The Summer of Hydrogen

NASA Technical Reports Server (NTRS)

Weber, Philip

2008-01-01

Ground crew veterans at Kennedy Space Center still talk about what they call "the summer of hydrogen"-the long, frustrating months in 1990 when the shuttle fleet was grounded by an elusive hydrogen leak that foiled our efforts to fill the orbiter's external fuel tank. Columbia (STS-35) was on Launch Pad A for a scheduled May 30 launch when we discovered the hydrogen leak during - tanking. The external fuel tank is loaded through the orbiter. Liquid hydrogen flows through a 17-inch umbilical between the orbiter and the tank. During fueling, we purge the aft fuselage with gaseous nitrogen to reduce the risk of fire, and we have a leak-detection system in the mobile launch platform, which samples (via tygon tubing) the atmosphere in and around the vehicle, drawing it down to a mass spectrometer that analyzes its composition. When we progressed to the stage of tanking where liquid hydrogen flows through the vehicle, the concentration of hydrogen approached four percent-the limit above which it would be dangerously flammable. We had a leak. We did everything we could think of to find it, and the contractor who supplied the flight hardware was there every day, working alongside us. We did tanking tests, which involved instrumenting the suspected leak sources, and cryo-loaded the external tank to try to isolate precisely where the leak originated. We switched out umbilicals; we replaced the seals between the umbilical and the orbiter. We inspected the seals microscopically and found no flaws. We replaced the recirculation pumps, and we found and replaced a damaged teflon seal in a main propulsion system detent cover, which holds the prevalve-the main valve supplying hydrogen to Space Shuttle Main Engine 3 -in the open position. The seal passed leak tests at ambient temperature but leaked when cryogenic temperatures were applied. We added new leak sensors-up to twenty at a time and tried to be methodical in our placements to narrow down the possible sources of the problem. We even switched orbiters, sending Columbia back to the Vehicle Assembly Building and bringing out Atlantis, scheduled to fly as STS-38. Two shuttles on their mobile launchers passing in the night was a majestic sight, but not one you want to see if you're trying to get an orbiter launched. None of this told us where the leak was, or if we were dealing with more than one leak source.

Chemochromic Hydrogen Sensors

NASA Technical Reports Server (NTRS)

Wiggins, Bryan C.

2007-01-01

As fossil fuel supplies decline, hydrogen is quickly becoming an increasingly important fuel source. Currently hydrogen is the prime fuel of today's space vehicles (e.g., Space Shuttle) and featured as a fuel for some prototype vehicles such as the BMW seven series model. Hydrogen is a colorless, odorless gas with a 4% lower explosive limit which makes leak detection a priority. In an effort to support the use of hydrogen, a chemochromic (color changing) sensor was developed that is robust, simple to use, and does not require active operation. It can be made into a thin tape which can be conveniently used for leak detection at flanges, valves, or outlets. Chemochromic sensors can be either reversible or irreversible; however, irreversible chemochromic sensors will be analyzed in this report. The irreversible sensor is useful during hazardous operations when personnel cannot be present. To actively monitor leaks, testing of the irreversible sensor against environmental effects was completed and results indicated this material is suitable for outdoor use in the harsh beachside environment of Kennedy Space Center. The experiments in this report will give additional results to the environmental testing by adding solid rocket booster residue as a variable. The primary motivation for these experiments is to prepare the sensors for the launch pad environment at the Kennedy Space Center. In an effort to simulate the atmosphere at the pads before and after launch, the chemochromic sensors are exposed to solid rocket residue under various conditions.

REACTOR FUEL ELEMENTS TESTING CONTAINER

DOEpatents

Whitham, G.K.; Smith, R.R.

1963-01-15

This patent shows a method for detecting leaks in jacketed fuel elements. The element is placed in a sealed tank within a nuclear reactor, and, while the reactor operates, the element is sparged with gas. The gas is then led outside the reactor and monitored for radioactive Xe or Kr. (AEC)

DoD Fuel Facilities Criteria

DTIC Science & Technology

2015-04-27

Pantograph Feb-2010 UFGS 33 58 00 Leak Detection for Fueling Systems Apr-2008 UFGS 33 52 43.13 Aviation Fuel Piping Feb-2010 UFGS 33 59 00 Tightness of... Pipeline Pressure Testing Guidelines  Specifications  Questions 2 7/12/2017 3 7/12/2017 DoD Fuels Facilities Documents  Unified...UFGS)  Most in the 33 nn nn series  Associated with Standard Designs  Available on WBDG site  Coating Systems 4 7/12/2017 Pipeline

Investigative techniques used to locate the liquid hydrogen leakage on the Space Shuttle Main Propulsion System

NASA Technical Reports Server (NTRS)

Hammock, William R., Jr.; Cota, Phillip E., Jr.; Rosenbaum, Bernard J.; Barrett, Michael J.

1991-01-01

Standard leak detection methods at ambient temperature have been developed in order to prevent excessive leakage from the Space Shuttle liquid oxygen and liquid hydrogen Main Propulsion System. Unacceptable hydrogen leakage was encountered on the Columbia and Atlantis flight vehicles in the summer of 1990 after the standard leak check requirements had been satisfied. The leakage was only detectable when the fuel system was exposed to subcooled liquid hydrogen during External Tank loading operations. Special instrumentation and analytical tools were utilized during a series of propellant tanking tests in order to identify the sources of the hydrogen leakage. After the leaks were located and corrected, the physical characteristics of the leak sources were analyzed in an effort to understand how the discrepancies were introduced and why the leakage had evaded the standard leak detection methods. As a result of the post-leak analysis, corrective actions and leak detection improvements have been implemented in order to preclude a similar incident.

40 CFR 52.1120 - Identification of plan.

Code of Federal Regulations, 2013 CFR

2013-07-01

... a new regulation 310 CMR 7.19 “Interim Sulfur-in-Fuel Limitations for Fossil Fuel Utilization... May 22, 1985, including Method 27, record form, potential leak points, major tank truck leak sources...

40 CFR 52.1120 - Identification of plan.

Code of Federal Regulations, 2010 CFR

2010-07-01

... a new regulation 310 CMR 7.19 “Interim Sulfur-in-Fuel Limitations for Fossil Fuel Utilization... May 22, 1985, including Method 27, record form, potential leak points, major tank truck leak sources...

40 CFR 52.1120 - Identification of plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

... a new regulation 310 CMR 7.19 “Interim Sulfur-in-Fuel Limitations for Fossil Fuel Utilization... May 22, 1985, including Method 27, record form, potential leak points, major tank truck leak sources...

40 CFR 52.1120 - Identification of plan.

Code of Federal Regulations, 2014 CFR

2014-07-01

... a new regulation 310 CMR 7.19 “Interim Sulfur-in-Fuel Limitations for Fossil Fuel Utilization... May 22, 1985, including Method 27, record form, potential leak points, major tank truck leak sources...

40 CFR 52.1120 - Identification of plan.

Code of Federal Regulations, 2012 CFR

2012-07-01

... a new regulation 310 CMR 7.19 “Interim Sulfur-in-Fuel Limitations for Fossil Fuel Utilization... May 22, 1985, including Method 27, record form, potential leak points, major tank truck leak sources...

Development of a Laminar Flame Test Facility for Bio-Diesel Characterization

DTIC Science & Technology

2009-12-01

heat from the fuel injector during operation. NPT Threaded Holes Bolts and Nuts Stainless Steel Pipes 17 Figure 3. Top Flange of the...3 2. Pre- Heat Temperature... Piping Systems........................... 37 2. Leak Test for Combustion Chamber .................................... 38 3. Calibration of High Speed

A Fully Redundant On-Line Mass Spectrometer System Used to Monitor Cryogenic Fuel Leaks on the Space Shuttle

NASA Technical Reports Server (NTRS)

Griffin, T. P.; Naylor, G. R.; Haskell, W. D.; Breznik, G. S.; Mizell, C. A.; Steinrock, Todd (Technical Monitor)

2001-01-01

This paper presents an on-line mass spectrometer designed to monitor for cryogenic leaks on the Space Shuttle. The topics include: 1) Hazardous Gas Detection Lab; 2) LASRE Test Support; 3) Background; 4) Location of Systems; 5) Sample Lines for Gas Detection; 6) Problems with Current Systems; 7) Requirements for New System (Nitrogen and Helium Background); and 8) HGDS 2000. This paper is in viewgraph form.

78 FR 49237 - Airworthiness Directives; the Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... could cause a fuel leak near an ignition source (e.g., hot brakes or engine exhaust nozzle..., which could cause a fuel leak near an ignition source (e.g., hot brakes or engine exhaust nozzle... brakes or engine exhaust nozzle), consequently leading to a fuel-fed fire. (f) Compliance Comply with...

78 FR 48826 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-12

... could cause a fuel leak near an ignition source (e.g., hot brakes or engine exhaust nozzle... could cause a fuel leak near an ignition source (e.g., hot brakes or engine nozzle), consequently... ignition source (e.g., hot brakes or engine nozzle), consequently leading to a fuel-fed fire. (f...

Alternative Fuels Data Center: Equipment Options for E85 Fueling Systems

Science.gov Websites

equipment includes an overfill protection device, a leak detection device, shear valves, fill and vapor caps protection, leak detection, shear valves, fill and vapor caps, adaptors, containment sumps, and all

Using Decision Trees to Detect and Isolate Simulated Leaks in the J-2X Rocket Engine

NASA Technical Reports Server (NTRS)

Schwabacher, Mark A.; Aguilar, Robert; Figueroa, Fernando F.

2009-01-01

The goal of this work was to use data-driven methods to automatically detect and isolate faults in the J-2X rocket engine. It was decided to use decision trees, since they tend to be easier to interpret than other data-driven methods. The decision tree algorithm automatically "learns" a decision tree by performing a search through the space of possible decision trees to find one that fits the training data. The particular decision tree algorithm used is known as C4.5. Simulated J-2X data from a high-fidelity simulator developed at Pratt & Whitney Rocketdyne and known as the Detailed Real-Time Model (DRTM) was used to "train" and test the decision tree. Fifty-six DRTM simulations were performed for this purpose, with different leak sizes, different leak locations, and different times of leak onset. To make the simulations as realistic as possible, they included simulated sensor noise, and included a gradual degradation in both fuel and oxidizer turbine efficiency. A decision tree was trained using 11 of these simulations, and tested using the remaining 45 simulations. In the training phase, the C4.5 algorithm was provided with labeled examples of data from nominal operation and data including leaks in each leak location. From the data, it "learned" a decision tree that can classify unseen data as having no leak or having a leak in one of the five leak locations. In the test phase, the decision tree produced very low false alarm rates and low missed detection rates on the unseen data. It had very good fault isolation rates for three of the five simulated leak locations, but it tended to confuse the remaining two locations, perhaps because a large leak at one of these two locations can look very similar to a small leak at the other location.

Hydrogen Research for Spaceport and Space-Based Applications: Hydrogen Sensors and Systems. Part 2

NASA Technical Reports Server (NTRS)

Anderson, Tim; Balaban, Canan

2008-01-01

The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. Sensor systems research was focused on hydrogen leak detection and smart sensors with adaptive feedback control for fuel cells. The goal was to integrate multifunction smart sensors, low-power high-efficiency wireless circuits, energy harvesting devices, and power management circuits in one module. Activities were focused on testing and demonstrating sensors in a realistic environment while also bringing them closer to production and commercial viability for eventual use in the actual operating environment.

Ultrasonic Detectors Safely Identify Dangerous, Costly Leaks

NASA Technical Reports Server (NTRS)

2013-01-01

In 1990, NASA grounded its space shuttle fleet. The reason: leaks detected in the hydrogen fuel systems of the Space Shuttles Atlantis and Columbia. Unless the sources of the leaks could be identified and fixed, the shuttles would not be safe to fly. To help locate the existing leaks and check for others, Kennedy Space Center engineers used portable ultrasonic detectors to scan the fuel systems. As a gas or liquid escapes from a leak, the resulting turbulence creates ultrasonic noise, explains Gary Mohr, president of Elmsford, New York-based UE Systems Inc., a long-time leader in ultrasonic detector technologies. "In lay terms, the leak is like a dog whistle, and the detector is like the dog ear." Because the ultrasound emissions from a leak are highly localized, they can be used not only to identify the presence of a leak but also to help pinpoint a leak s location. The NASA engineers employed UE s detectors to examine the shuttle fuel tanks and solid rocket boosters, but encountered difficulty with the devices limited range-certain areas of the shuttle proved difficult or unsafe to scan up close. To remedy the problem, the engineers created a long-range attachment for the detectors, similar to "a zoom lens on a camera," Mohr says. "If you are on the ground, and the leak is 50 feet away, the detector would now give you the same impression as if you were only 25 feet away." The enhancement also had the effect of reducing background noise, allowing for a clearer, more precise detection of a leak s location.

CHEMICALS STORED IN USTS: CHARACTERISTICS AND LEAK DETECTION

EPA Science Inventory

The regulations Issued by the U.S. Environmental Protection Agency (EPA) In 1988 require, with several exceptions, that the Integrity of underground storage tank (UST) systems containing petroleum fuels and hazardous chemicals be routinely tested. The regulatory standards for ...

Pool-site fuel inspection and examination techniques applied by the Kraftwerk Union Aktiengesellschaft Fuel Service. [PWR; BWR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knaab, H.; Knecht, K.

The need for pool-site inspection and examination of fuel assemblies was recognized by Kraftwerk Union Aktiengesellschaft with the commissioning of the first nuclear power stations. A wet sipping method has demonstrated high reliability in detection of leaking fuel assemblies. The visual inspection system is a versatile tool. It can be supplemented by attaching devices for oxide thickness measurement or surface replication. Repair of leaking pressurized water reactor fuel assemblies has improved fuel utilization. Applied methods and typical results are described.

Novel load responsive multilayer insulation with high in-atmosphere and on-orbit thermal performance

NASA Astrophysics Data System (ADS)

Dye, S.; Kopelove, A.; Mills, G. L.

2012-04-01

Aerospace cryogenic systems require lightweight, high performance thermal insulation to preserve cryopropellants both pre-launch and on-orbit. Current technologies have difficulty meeting all requirements, and advances in insulation would benefit cryogenic upper stage launch vehicles, LH2 fueled aircraft and ground vehicles, and provide capabilities for sub-cooled cryogens for space-borne instruments and orbital fuel depots. This paper reports the further development of load responsive multilayer insulation (LRMLI) that has a lightweight integrated vacuum shell and provides high thermal performance both in-air and on-orbit. LRMLI is being developed by Quest Product Development and Ball Aerospace under NASA contract, with prototypes designed, built, installed and successfully tested. A 3-layer LRMLI blanket (0.63 cm thick, 77 K cold, 295 K hot) had a measured heat leak of 6.6 W/m2 in vacuum and 40.6 W/m2 in air at one atmosphere. In-air LRMLI has an 18× advantage over Spray On Foam Insulation (SOFI) in heat leak per thickness and a 16× advantage over aerogel. On-orbit LRMLI has a 78× lower heat leak than SOFI per thickness and 6× lower heat leak than aerogel. The Phase II development of LRMLI is reported with a modular, flexible, thin vacuum shell and improved on-orbit performance. Structural and thermal analysis and testing results are presented. LRMLI mass and thermal performance is compared to SOFI, aerogel and MLI over SOFI.

New acoustic techniques for leak detection in fossil fuel plant components

NASA Astrophysics Data System (ADS)

Parini, G.; Possa, G.

Two on-line acoustic monitoring techniques for leak detection in feedwater preheaters and boilers of fossil fuel power plants are presented. The leak detection is based on the acoustic noise produced by the turbulent leak outflow. The primary sensors are piezoelectric pressure transducers, installed near the feedwater preheater inlets, in direct contact with the water, or mounted on boiler observation windows. The frequency band of the auscultation ranges from a few kHz, to 10 to 15 kHz. The signals are characterized by their rms value, continuously recorded by means of potentiometric strip chart recorders. The leak occurrence is signalled by the signal rms overcoming predetermined threshold levels. Sensitivity, reliability, acceptance in plant control practice, and costs-benefits balance are satisfactory.

Portable Rapid Test Fuel Tank Leak Detection System

DTIC Science & Technology

2010-04-01

polished. Lid is tig welded . Media: Water Result: Bubbles (encircled in red) only at threaded port and at top of the center as shown in Picture 2...bimetallic strip ( ) quartz crystal ( ) thermistor ( ) other (describe briefly) B-3 If product temperature is not

Spray sealing: A breakthrough in integral fuel tank sealing technology

NASA Astrophysics Data System (ADS)

Richardson, Martin D.; Zadarnowski, J. H.

1989-11-01

In a continuing effort to increase readiness, a new approach to sealing integral fuel tanks is being developed. The technique seals potential leak sources by spraying elastomeric materials inside the tank cavity. Laboratory evaluations project an increase in aircraft supportability and reliability, an improved maintainability, decreasing acquisition and life cycle costs. Increased usable fuel volume and lower weight than conventional bladders improve performance. Concept feasibility was demonstrated on sub-scale aircraft fuel tanks. Materials were selected by testing sprayable elastomers in a fuel tank environment. Chemical stability, mechanical properties, and dynamic durability of the elastomer are being evaluated at the laboratory level and in sub-scale and full scale aircraft component fatigue tests. The self sealing capability of sprayable materials is also under development. Ballistic tests show an improved aircraft survivability, due in part to the elastomer's mechanical properties and its ability to damp vibrations. New application equipment, system removal, and repair methods are being investigated.

Fuel subassembly leak test chamber for a nuclear reactor

DOEpatents

Divona, Charles J.

1978-04-04

A container with a valve at one end is inserted into a nuclear reactor coolant pool. Once in the pool, the valve is opened by a mechanical linkage. An individual fuel subassembly is lifted into the container by a gripper; the valve is then closed providing an isolated chamber for the subassembly. A vacuum is drawn on the chamber to encourage gaseous fission product leakage through any defects in the cladding of the fuel rods comprising the subassembly; this leakage may be detected by instrumentation, and the need for replacement of the assembly ascertained.

Fuel Cell Vehicle Fleet and Hydrogen Infrastructure at Hickam Air Force Base

DTIC Science & Technology

2009-04-27

there has been no evidence of busbar or endplate corrosion in the manifold region. The crossover leak was the result of a failed humidification device...leak that develops within the humidifier can lead to a combustible gas mixture entering the fuel cell stack. This humidification device has been

24 CFR 3285.605 - Fuel supply system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... designed for a pressure that is at least 7 inches of water column [4oz./in.2 or 0.25 psi] and not more than 14 inches of water column [8 oz./in.2 or 0.5 psi]. If gas from any supply source exceeds, or could... connector quick-disconnect. (c) Testing procedures. The gas system must be inspected and tested for leaks...

In-situ diagnostic tools for hydrogen transfer leak characterization in PEM fuel cell stacks part II: Operational applications

NASA Astrophysics Data System (ADS)

Niroumand, Amir M.; Homayouni, Hooman; DeVaal, Jake; Golnaraghi, Farid; Kjeang, Erik

2016-08-01

This paper describes a diagnostic tool for in-situ characterization of the rate and distribution of hydrogen transfer leaks in Polymer Electrolyte Membrane (PEM) fuel cell stacks. The method is based on reducing the air flow rate from a high to low value at a fixed current, while maintaining an anode overpressure. At high air flow rates, the reduction in air flow results in lower oxygen concentration in the cathode and therefore reduction in cell voltages. Once the air flow rate in each cell reaches a low value at which the cell oxygen-starves, the voltage of the corresponding cell drops to zero. However, oxygen starvation results from two processes: 1) the electrochemical oxygen reduction reaction which produces current; and 2) the chemical reaction between oxygen and the crossed over hydrogen. In this work, a diagnostic technique has been developed that accounts for the effect of the electrochemical reaction on cell voltage to identify the hydrogen leak rate and number of leaky cells in a fuel cell stack. This technique is suitable for leak characterization during fuel cell operation, as it only requires stack air flow and voltage measurements, which are readily available in an operational fuel cell system.

Fuel containment, lightning protection and damage tolerance in large composite primary aircraft structures

NASA Technical Reports Server (NTRS)

Griffin, Charles F.; James, Arthur M.

1985-01-01

The damage-tolerance characteristics of high strain-to-failure graphite fibers and toughened resins were evaluated. Test results show that conventional fuel tank sealing techniques are applicable to composite structures. Techniques were developed to prevent fuel leaks due to low-energy impact damage. For wing panels subjected to swept stroke lightning strikes, a surface protection of graphite/aluminum wire fabric and a fastener treatment proved effective in eliminating internal sparking and reducing structural damage. The technology features developed were incorporated and demonstrated in a test panel designed to meet the strength, stiffness, and damage tolerance requirements of a large commercial transport aircraft. The panel test results exceeded design requirements for all test conditions. Wing surfaces constructed with composites offer large weight savings if design allowable strains for compression can be increased from current levels.

In-pile and out-of-pile testing of a molybdenum-uranium dioxide cermet fueled themionic diode

NASA Technical Reports Server (NTRS)

Diianni, D. C.

1972-01-01

The behavior of Mo-UO2 cermet fuel in a diode for thermionic reactor application was studied. The diode had a Mo-0.5 Ti emitter and niobium collector. Output power ranged from 1.4 to 2.8 W/cm squared at emitter and collector temperatures of 1500 deg and 540 C. Thermionic performance was stable within the limits of the instrumentation sensitivity. Through 1000 hours of in-pile operation the emitter was dimensionally stable. However, some fission gases (15 percent) leaked through an inner clad imperfection that occurred during fuel fabrication.

Sample Delivery and Computer Control Systems for Detecting Leaks in the Main Engines of the Space Shuttle

NASA Technical Reports Server (NTRS)

Griffin, Timothy P.; Naylor, Guy R.; Hritz, Richard J.; Barrett, Carolyn A.

1997-01-01

The main engines of the Space Shuttle use hydrogen and oxygen as the fuel and oxidant. The explosive and fire hazards associated with these two components pose a serious danger to personnel and equipment. Therefore prior to use the main engines undergo extensive leak tests. Instead of using hazardous gases there tests utilize helium as the tracer element. This results in a need to monitor helium in the ppm level continuously for hours. The major challenge in developing such a low level gas monitor is the sample delivery system. This paper discuss a system developed to meet the requirements while also being mobile. Also shown is the calibration technique, stability, and accuracy results for the system.

Bioenvironmental Engineer’s Guide to Indoor Air Quality Surveys

DTIC Science & Technology

2014-09-01

housekeeping practices •Fresh air intake located near contaminant source •Check for sewer line leak, septic tank leak, fuel tank leaks...make-up air •Dirty coils/filters •Sewer gas, drain traps, sanitary vents •Leaky tanks , spills •Cleaning products, pesticides •Poor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaech, J.L.

The use of a pooling technique in leak testing Plutonium Recycle Test Reactor fuel elements to reduce the number of tests is discussed. Since the proportion of defectives in this case is small, application of the method would suggest that the group size be large. It was suggested that additional savings might be introduced by subgrouping the originally grouped items in the event of a positive result, rather than testing them individually. An investigation was made to determine optimum subgrouping sizes. (M.C.G.)

In situ formation of leak-free polyethylene glycol (PEG) membranes in microfluidic fuel cells.

PubMed

Ho, W F; Lim, K M; Yang, K-L

2016-11-29

Membraneless microfluidic fuel cells operated under two co-laminar flows often face serious fuel cross-over problems, especially when flow rates are close to zero. In this study, we show that polyethylene glycol (PEG) monomers can be cross-linked inside microfluidic channels to form leak-free PEG membranes, which prevent mixing of two incompatible electrolyte solutions while allowing diffusion of certain molecules (e.g. glucose) and ions. By using PEG monomers of different molecular weights and cross-linking conditions, we are able to tailor selectivity of the membrane to allow passage of glucose while blocking larger molecules such as trypan blue. As a proof of principle, a microfluidic fuel cell with a PEG membrane and two incompatible electrolytes (acid and base) is demonstrated. Thanks to the leak-free nature of the PEG membrane, these two electrolytes do not mix together even at very slow flow rates. This microfluidic fuel cell is able to generate a voltage up to ∼450 mV from 10 mM of glucose with a flow rate of 20 μL min -1 . This microfluidic fuel cell is potentially useful as a miniature power source for many applications.

Inert matrix fuel in dispersion type fuel elements

NASA Astrophysics Data System (ADS)

Savchenko, A. M.; Vatulin, A. V.; Morozov, A. V.; Sirotin, V. L.; Dobrikova, I. V.; Kulakov, G. V.; Ershov, S. A.; Kostomarov, V. P.; Stelyuk, Y. I.

2006-06-01

The advantages of using inert matrix fuel (IMF) as a dispersion fuel in an aluminium alloy matrix are considered, in particular, low temperatures in the fuel centre, achievable high burn-ups, serviceability in transients and an environmentally friendly process of fuel rod fabrication. Two main versions of IMF are under development at A.A. Bochvar Institute, i.e. heterogeneous or isolated distribution of plutonium. The out-of-pile results on IMF loaded with uranium dioxide as plutonium simulator are presented. Fuel elements with uranium dioxide composition fabricated at A.A. Bochvar Institute are currently under MIR tests (RIAR, Dimitrovgrad). The fuel elements reached a burn-up of 88 MW d kg-1 (equivalent to the burn up of the standard uranium dioxide pelletized fuel) without loss of leak-tightness of the cladding. The feasibility of fabricating IMF of these particular types with plutonium dioxide is considered with a view to in-pile irradiation.

Real-Time Model-Based Leak-Through Detection within Cryogenic Flow Systems

NASA Technical Reports Server (NTRS)

Walker, M.; Figueroa, F.

2015-01-01

The timely detection of leaks within cryogenic fuel replenishment systems is of significant importance to operators on account of the safety and economic impacts associated with material loss and operational inefficiencies. Associated loss in control of pressure also effects the stability and ability to control the phase of cryogenic fluids during replenishment operations. Current research dedicated to providing Prognostics and Health Management (PHM) coverage of such cryogenic replenishment systems has focused on the detection of leaks to atmosphere involving relatively simple model-based diagnostic approaches that, while effective, are unable to isolate the fault to specific piping system components. The authors have extended this research to focus on the detection of leaks through closed valves that are intended to isolate sections of the piping system from the flow and pressurization of cryogenic fluids. The described approach employs model-based detection of leak-through conditions based on correlations of pressure changes across isolation valves and attempts to isolate the faults to specific valves. Implementation of this capability is enabled by knowledge and information embedded in the domain model of the system. The approach has been used effectively to detect such leak-through faults during cryogenic operational testing at the Cryogenic Testbed at NASA's Kennedy Space Center.

40 CFR 86.608-98 - Test procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... voltage supply to the chemiluminescent analyzers is placed in the standby position.) (B) The manufacturer... system to ensure the absence of any leaks of liquid or vapor to the atmosphere by applying a pressure of 14.5±0.5 inches of water (3.6±0.1 Kpa) to the fuel system allowing the pressure to stabilize and...

Diffusion Bonding of Silicon Carbide for a Micro-Electro-Mechanical Systems Lean Direct Injector

NASA Technical Reports Server (NTRS)

Halbig, Michael C.; Singh, Mrityunjay; Shpargel, Tarah P.; Kiser, James D.

2006-01-01

Robust approaches for joining silicon carbide (SiC) to silicon carbide sub-elements have been developed for a micro-electro-mechanical systems lean direct injector (MEMS LDI) application. The objective is to join SiC sub-elements to form a leak-free injector that has complex internal passages for the flow and mixing of fuel and air. Previous bonding technology relied upon silicate glass interlayers that were not uniform or leak free. In a newly developed joining approach, titanium foils and physically vapor deposited titanium coatings were used to form diffusion bonds between SiC materials during hot pressing. Microscopy results show the formation of well adhered diffusion bonds. Initial tests show that the bond strength is much higher than required for the component system. Benefits of the joining technology are fabrication of leak free joints with high temperature and mechanical capability.

METHOD OF TESTING FOR LEAKS

DOEpatents

Creutz, E.C.; McAdams, Wm.A.; Foss, M.H.

1958-07-22

A method is described for detecting minute holes In fuel element jackets. The method comprises submerging the jacketed body in an atmosphere of a radioactive gas under pressure, the radioactive emanations from said gas being sufficientiy penetratIng to penetrate the jacket of the jacketed body. After the jacketed body is removed from the radtoactive gas atmosphere, it is exannined for the presence of emanations from radioactive gas which entered the jacketed body through the minute holes. In this manner, the detectton of radioactive emanations is a positive indication that the fuel element is not perfectly sealed.

Wrapped Multilayer Insulation

NASA Technical Reports Server (NTRS)

Dye, Scott A.

2015-01-01

New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/sq m, or 27 percent of the heat leak of conventional MLI (26.7 W/sq m). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

Wrapped Multilayer Insulation

NASA Technical Reports Server (NTRS)

Dye, Scott A.

2015-01-01

New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

AFP no. 28 (General Electric Lynn Manufacturing dept). is located in the City of Everett, Mass. The facility is composed of 10 buildings having 344,342 square feet of floor space on a 43-acre tract. The plant is engaged in the manufacture of large jet engine components and sub-assemblies. AFT 29 (General Electric River Works Facility) is located in the City of Lynn, Mass. AFT No. 29 is part of the General Electric Aircraft Engine Business Group and the facilities are used for testing and assembly of jet engines. The following conclusions have been developed based on the results of themore » project team's field inspection, review of plant records and files, and interviews with plant personnel. Each of the sites listed below was ranked using the HARM system and was determined to have a sufficient potential for environmental contamination to warrant some degree of follow-on investigation. AFB no. 28: Waste sump and chip storage area; and AFT no. 29: Underground fuel line leaks and underground fuel storage tank leak.« less

30 CFR 75.1906 - Transport of diesel fuel.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Transport of diesel fuel. 75.1906 Section 75... diesel fuel. (a) Diesel fuel shall be transported only by diesel fuel transportation units or in safety... fuel storage facilities. (c) Safety cans that leak must be promptly removed from the mine. (d) Diesel...

33 CFR 183.524 - Fuel pumps.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Fuel pumps. 183.524 Section 183... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically...

33 CFR 183.524 - Fuel pumps.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel pumps. 183.524 Section 183... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically...

33 CFR 183.524 - Fuel pumps.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Fuel pumps. 183.524 Section 183... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically...

33 CFR 183.524 - Fuel pumps.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Fuel pumps. 183.524 Section 183... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically...

33 CFR 183.524 - Fuel pumps.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Fuel pumps. 183.524 Section 183... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.524 Fuel pumps. (a) Each diaphragm pump must not leak fuel from the pump if the primary diaphragm fails. (b) Each electrically...

40 CFR 65.146 - Nonflare control devices used for equipment leaks only.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Closed Vent Systems, Control Devices, and Routing to a Fuel Gas System or a Process § 65.146 Nonflare control devices used for equipment leaks only...

Intraoperative leak testing has no correlation with leak after laparoscopic sleeve gastrectomy.

PubMed

Sethi, Monica; Zagzag, Jonathan; Patel, Karan; Magrath, Melissa; Somoza, Eduardo; Parikh, Manish S; Saunders, John K; Ude-Welcome, Aku; Schwack, Bradley F; Kurian, Marina S; Fielding, George A; Ren-Fielding, Christine J

2016-03-01

Staple line leak is a serious complication of sleeve gastrectomy. Intraoperative methylene blue and air leak tests are routinely used to evaluate for leak; however, the utility of these tests is controversial. We hypothesize that the practice of routine intraoperative leak testing is unnecessary during sleeve gastrectomy. A retrospective cohort study was designed using a prospectively collected database of seven bariatric surgeons from two institutions. All patients who underwent sleeve gastrectomy from March 2012 to November 2014 were included. The performance of intraoperative leak testing and the type of test (air or methylene blue) were based on surgeon preference. Data obtained included BMI, demographics, comorbidity, presence of intraoperative leak test, result of test, and type of test. The primary outcome was leak rate between the leak test (LT) and no leak test (NLT) groups. SAS version 9.4 was used for univariate and multivariate analyses. A total of 1550 sleeve gastrectomies were included; most were laparoscopic (99.8%), except for one converted and two open cases. Routine intraoperative leak tests were performed in 1329 (85.7%) cases, while 221 (14.3%) did not have LTs. Of the 1329 cases with LTs, there were no positive intraoperative results. Fifteen (1%) patients developed leaks, with no difference in leak rate between the LT and NLT groups (1 vs. 1%, p = 0.999). After adjusting for baseline differences between the groups with a propensity analysis, the observed lack of association between leak and intraoperative leak test remained. In this cohort, leaks presented at a mean of 17.3 days postoperatively (range 1-67 days). Two patients with staple line leaks underwent repeat intraoperative leak testing at leak presentation, and the tests remained negative. Intraoperative leak testing has no correlation with leak due to laparoscopic sleeve gastrectomy and is not predictive of the later development of staple line leak.

Fatigue and creep to leak tests of proton exchange membranes using pressure-loaded blisters

NASA Astrophysics Data System (ADS)

Li, Yongqiang; Dillard, David A.; Case, Scott W.; Ellis, Michael W.; Lai, Yeh-Hung; Gittleman, Craig S.; Miller, Daniel P.

In this study, three commercially available proton exchange membranes (PEMs) are biaxially tested using pressure-loaded blisters to characterize their resistance to gas leakage under either static (creep) or cyclic fatigue loading. The pressurizing medium, air, is directly used for leak detection. These tests are believed to be more relevant to fuel cell applications than quasi-static uniaxial tensile-to-rupture tests because of the use of biaxial cyclic and sustained loading and the use of gas leakage as the failure criterion. They also have advantages over relative humidity cycling test, in which a bare PEM or catalyst coated membrane is clamped with gas diffusion media and flow field plates and subjected to cyclic changes in relative humidity, because of the flexibility in allowing controlled mechanical loading and accelerated testing. Nafion ® NRE-211 membranes are tested at three different temperatures and the time-temperature superposition principle is used to construct stress-lifetime master curve. Tested at 90 °C, 2%RH extruded Ion Power ® N111-IP membranes have a longer lifetime than Gore™-Select ® 57 and Nafion ® NRE-211 membranes.

Neutronic fuel element fabrication

DOEpatents

Korton, George

2004-02-24

This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure by encompassing the sides of the fuel element between the header plates.

Drying results of K-Basin fuel element 1990 (Run 1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marschman, S.C.; Abrefah, J.; Klinger, G.S.

1998-06-01

The water-filled K-Basins in the Hanford 100-Area have been used to store N-Reactor spent nuclear fuel (SNF) since the 1970s. Because some leaks in the basins have been detected and some of the fuel is breached due to handling damage and corrosion, efforts are underway to remove the fuel elements from wet storage. An Integrated Process Strategy (IPS) has been developed to package, dry, transport, and store these metallic uranium fuels in an interim storage facility on the Hanford Site (WHC 1995). Information required to support the development of the drying processes, and the required safety analyses, is being obtainedmore » from characterization tests conducted on fuel elements removed from the K-Basins. A series of whole element drying tests (reported in separate documents, see Section 8.0) have been conducted by Pacific Northwest National Laboratory (PNNL) on several intact and damaged fuel elements recovered from both the K-East and K-West Basins. This report documents the results of the first of those tests (Run 1), which was conducted on an N-Reactor inner fuel element (1990) that had been stored underwater in the K-West Basin (see Section 2.0). This fuel element was subjected to a combination of low- and high-temperature vacuum drying treatments that were intended to mimic, wherever possible, the fuel treatment strategies of the IPS. The testing was conducted in the Whole Element Furnace Testing System, described in Section 3.0, located in the Postirradiation Testing Laboratory (PTL, 327 Building). The test conditions and methodology are given in Section 4.0, and the experimental results provided in Section 5.0. These results are further discussed in Section 6.0.« less

AIR EMISSIONS FROM THE TREATMENT OF SOILS CONTAMINATED WITH PETROLEUM FUELS AND OTHER SUBSTANCES

EPA Science Inventory

The report updates a 1992 report that summarizes available information on air emissions from the treatment of soils contaminated with fuels. Soils contaminated by leaks or spills of fuel products, such as gasoline or jet fuel, are a nationwide concern. Air emissions during remedi...

Fiber Optic Cable Feedthrough and Sealing

NASA Technical Reports Server (NTRS)

Fan, Robert J.

1998-01-01

A novel fiberoptic hermetic bulkhead feedthrough has been developed which will offer cryogenic sealing at leak rates of 10(exp -11) cc/sec helium. This feedthrough was developed for NASA in response to needs for a hermetically sealed feedthrough which could withstand a range of temperatures from low cryogenic (-196 C), due to liquid fuels and oxidizers, to high temperatures (+200 C) encountered in the proximity of combustion gasses. The development effort will be reported from conceptual design of single and multi-channel feedthrough units with single interconnection interfaces to units with double-ended interconnection interfaces. Various combinations of fiber/buffers are reported with recommendations based on test results. A comprehensive series of environmental and mechanical tests were performed to evaluate the feedthroughs in adverse conditions. Test results are reported including insertion loss, salt spray, sinusoidal vibration, random vibration, mechanical shock, thermal shock and humidity. A second set of feedthrough units was exposed to 3 different types of radiation. Optical transmittance changes during the tests were monitored and leak rate testing was done after each test. State-of-the-art technology in optical fiber feedthroughs constructed with polycrystalline ceramic is presented.

46 CFR 119.455 - Fuel piping.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the fuel supply line in the engine compartment. Strainers must be leak free. Strainers must be of the... as to close against the fuel flow, must be fitted in the fuel supply lines, one at the tank... copper tubing or a short length of flexible hose must be installed in the fuel supply line at or near the...

Feasibility of Carbon Fiber/PEEK Composites for Cryogenic Fuel Tank Applications

NASA Astrophysics Data System (ADS)

Doyle, K.; Doyle, A.; O Bradaigh, C. M.; Jaredson, D.

2012-07-01

This paper investigates the feasibility of CF/PEEK composites for manufacture of cryogenic fuel tanks for Next Generation Space Launchers. The material considered is CF/PEEK tape from Suprem SA and the proposed manufacturing process for the fuel tank is Automated Tape Placement. Material characterization was carried out on test laminates manufactured in an autoclave and also by Automated Tape Placement with in-situ consolidation. The results of the two processes were compared to establish if there is any knock down in properties for the automated tape placement process. A permeability test rig was setup with a helium leak detector and the effect of thermal cycling on the permeability properties of CF/PEEK was measured. A 1/10th scale demonstrator was designed and manufactured consisting of a cylinder manufactured by automated tape placement and an upper dome manufactured by autoclave processing. The assembly was achieved by Amorphous Interlayer Bonding with PEI.

49 CFR 176.905 - Stowage of motor vehicles or mechanical equipment.

Code of Federal Regulations, 2012 CFR

2012-10-01

... powered by an internal combustion engine, a fuel cell, batteries or a combination thereof, is subject to... leakage from the battery, engine, fuel cell, compressed gas cylinder or accumulator, or fuel tank, as..., each vehicle or mechanical equipment must be inspected for fuel leaks and identifiable faults in the...

77 FR 72200 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-05

... correctly on the engine fuel feed manifold couplings. This AD also requires inspecting the assembly of the engine fuel feed manifold rigid and full flexible couplings. This AD was prompted by reports of fuel leaks due to improperly assembled engine fuel feed manifold couplings. We are issuing this AD to detect...

Spent nuclear fuel integrity during dry storage - performance tests and demonstrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKinnon, M.A.; Doherty, A.L.

1997-06-01

This report summarizes the results of fuel integrity surveillance determined from gas sampling during and after performance tests and demonstrations conducted from 1983 through 1996 by or in cooperation with the US DOE Office of Commercial Radioactive Waste Management (OCRWM). The cask performance tests were conducted at Idaho National Engineering Laboratory (INEL) between 1984 and 1991 and included visual observation and ultrasonic examination of the condition of the cladding, fuel rods, and fuel assembly hardware before dry storage and consolidation of fuel, and a qualitative determination of the effects of dry storage and fuel consolidation on fission gas release frommore » the spent fuel rods. The performance tests consisted of 6 to 14 runs involving one or two loading, usually three backfill environments (helium, nitrogen, and vacuum backfills), and one or two storage system orientations. The nitrogen and helium backfills were sampled and analyzed to detect leaking spent fuel rods. At the end of each performance test, periodic gas sampling was conducted on each cask. A spent fuel behavior project (i.e., enhanced surveillance, monitoring, and gas sampling activities) was initiated by DOE in 1994 for intact fuel in a CASTOR V/21 cask and for consolidated fuel in a VSC-17 cask. The results of the gas sampling activities are included in this report. Information on spent fuel integrity is of interest in evaluating the impact of long-term dry storage on the behavior of spent fuel rods. Spent fuel used during cask performance tests at INEL offers significant opportunities for confirmation of the benign nature of long-term dry storage. Supporting cask demonstration included licensing and operation of an independent spent fuel storage installation (ISFSI) at the Virginia Power (VP) Surry reactor site. A CASTOR V/21, an MC-10, and a Nuclear Assurance NAC-I28 have been loaded and placed at the VP ISFSI as part of the demonstration program. 13 refs., 14 figs., 9 tabs.« less

Development and testing of dry chemicals in advanced extinguishing systems for jet engine nacelle fires

NASA Technical Reports Server (NTRS)

Altman, R. L.; Ling, A. C. (Editor); Mayer, L. A.; Myronik, D. J.

1979-01-01

The effectiveness of dry chemical in extinguishing and delaying reignition of fires resulting from hydrocarbon fuel leaking onto heated surfaces such as can occur in jet engine nacelles is studied. The commercial fire extinguishant dry chemical tried are sodium and potassium bicarbonate, carbonate, chloride, carbamate (Monnex), metal halogen, and metal hydroxycarbonate compounds. Synthetic and preparative procedures for new materials developed, a new concept of fire control by dry chemical agents, descriptions of experiment assemblages to test dry chemical fire extinguishant efficiencies in controlling fuel fires initiated by hot surfaces, comparative testing data for more than 25 chemical systems in a 'static' assemblage with no air flow across the heated surface, and similar comparative data for more than ten compounds in a dynamic system with air flows up to 350 ft/sec are presented.

Space Shuttle RCS Oxidizer Leak Repair for STS-26

NASA Technical Reports Server (NTRS)

Delventhal, R. A.; Faget, N. M.

1989-01-01

Following propellant loading of the Space Shuttle's reaction control system (RCS) for mission STS 26, an oxidizer leak was detected in the left orbital maneuvering system (OMS) pod, where the RCS is located. Subsequent investigation determined that the leak was isolated at a mechanical Dynatube fitting near the RCS nitrogen tetroxide tank. An intense effort was initiated to design, fabricate, and qualify a sealing device to stop the oxidizer leak externally so that the Space Shuttle launch could proceed. It was discovered that sealing devices called clamshells were widely used throughout the petrochemical and power generation industries to stop leaks developed in large diameter pipes which carry steam or other hazardous fluids. These clamshells are available in different diameters and strengths and are placed around the pipe at the location of the leak. A sealing compound is then injected under high pressure into the clamshell to stop the leak. This technology was scaled down and applied to the problem of stopping the leak on the Orbiter, which was on a half-inch diameter line in a nearly inaccessible location. Many obstacles had to be overcome such as determining that the sealing material would be compatible with the nitrogen tetroxide and ensuring that the clamshell would actually fit around the Dynatube fitting without interfering with other lines which were in close proximity. The effort at the NASA Johnson Space Center included materials compatibility testing of several sealants, design of a clamshell to fit in the confined compartment, and manufacture and qualification of the flight hardware. A clamshell was successfully placed around the Dynatube fitting on the Orbiter and the oxidizer leak was terminated. Then it was decided to apply this technology further and design clamshells for other mechanical fittings onboard the Orbiter and develop sealing compounds which will be compatible with fuels such as monomethyl hydrazine (MMH). The potential exists for using this type of sealing device in numerous other applications throughout the aerospace industry.

Evaluating Fuel Leak and Aging Infrastructure at Red Hill, Hawaii, the Largest Underground Fuel Storage Facility in the United States

EPA Pesticide Factsheets

Learn about how EPA Region 9, Hawaii’s Department of Health, U.S. Navy, and Defense Logistics Agency are working tprotect human health and the environment at the Red Hill Bulk Fuel Storage Facility in Hawaii.

Report: Suitability of Leak Detection Technology for Use In Ethanol-Blended Fuel Service

EPA Science Inventory

As the use of biofuels has increased in the last decade, there has been a level of concern over the effect that ethanol blends have on the material compatibility and operability of existing infrastructure. The focus of this research is to determine whether leak detection (LD) te...

Permeability of Impacted Coated Composite Laminates

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Findley, Benjamin

2002-01-01

Composite materials are being considered for use on future generations of Reusable Launch Vehicles (RLVs) for both fuel tanks and fuel feedlines. Through the use of composite materials NASA can reduce the overall weight of the vehicle dramatically. This weight savings can then be translated into an increase in the weight of payload sent into orbit, reducing the cost per pound of payload. It is estimated that by switching to composite materials for fuel tanks the weight of the tanks can be reduced by 40 percent, which translates to a total vehicle weight savings of 14 percent. In this research, carbon/epoxy composites were studied for fuel feedline applications. There are concerns about using composite materials for feedlines and fuel tanks because these materials are extremely vulnerable to impact in the form of inadvertent bumping or dropped tools both during installation and maintenance. Additionally, it has been found that some of the sample feedlines constructed have had leaks, and thus there may be a need to seal preexisting leaks in the composite prior to usage.

33 CFR 183.536 - Seals and gaskets in fuel filters and strainers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Seals and gaskets in fuel filters... Standards § 183.536 Seals and gaskets in fuel filters and strainers. (a) [Reserved] (b) Each gasket and each sealed joint in a fuel filter and strainer must not leak when subjected for 24 hours to a gasoline that...

33 CFR 183.536 - Seals and gaskets in fuel filters and strainers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Seals and gaskets in fuel filters... Standards § 183.536 Seals and gaskets in fuel filters and strainers. (a) [Reserved] (b) Each gasket and each sealed joint in a fuel filter and strainer must not leak when subjected for 24 hours to a gasoline that...

33 CFR 183.536 - Seals and gaskets in fuel filters and strainers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Seals and gaskets in fuel filters... Standards § 183.536 Seals and gaskets in fuel filters and strainers. (a) [Reserved] (b) Each gasket and each sealed joint in a fuel filter and strainer must not leak when subjected for 24 hours to a gasoline that...

33 CFR 183.536 - Seals and gaskets in fuel filters and strainers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Seals and gaskets in fuel filters... Standards § 183.536 Seals and gaskets in fuel filters and strainers. (a) [Reserved] (b) Each gasket and each sealed joint in a fuel filter and strainer must not leak when subjected for 24 hours to a gasoline that...

33 CFR 183.536 - Seals and gaskets in fuel filters and strainers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Seals and gaskets in fuel filters... Standards § 183.536 Seals and gaskets in fuel filters and strainers. (a) [Reserved] (b) Each gasket and each sealed joint in a fuel filter and strainer must not leak when subjected for 24 hours to a gasoline that...

Hydrogen Research for Spaceport and Space-Based Applications: Fuel Cell Projects

NASA Technical Reports Server (NTRS)

Anderson, Tim; Balaban, Canan

2008-01-01

The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. Fuel cell research focused on proton exchange membranes (PEM), solid oxide fuel cells (SOFC). Specific technologies included aircraft fuel cell reformers, new and improved electrodes, electrolytes, interconnect, and seals, modeling of fuel cells including CFD coupled with impedance spectroscopy. Research was conducted on new materials and designs for fuel cells, along with using embedded sensors with power management electronics to improve the power density delivered by fuel cells. Fuel cell applications considered were in-space operations, aviation, and ground-based fuel cells such as; powering auxiliary power units (APUs) in aircraft; high power density, long duration power supplies for interplanetary missions (space science probes and planetary rovers); regenerative capabilities for high altitude aircraft; and power supplies for reusable launch vehicles.

Modeling the Risk of Fire/Explosion Due to Oxidizer/Fuel Leaks in the Ares I Interstage

NASA Technical Reports Server (NTRS)

Ring, Robert W.; Stott, James E.; Hales, Christy

2008-01-01

A significant flight hazard associated with liquid propellants, such as those used in the upper stage of NASA's new Ares I launch vehicle, is the possibility of leakage of hazardous fluids resulting in a catastrophic fire/explosion. The enclosed and vented interstage of the Ares I contains numerous oxidizer and fuel supply lines as well as ignition sources. The potential for fire/explosion due to leaks during ascent depends on the relative concentrations of hazardous and inert fluids within the interstage along with other variables such as pressure, temperature, leak rates, and fluid outgasing rates. This analysis improves on previous NASA Probabilistic Risk Assessment (PRA) estimates of the probability of deflagration, in which many of the variables pertinent to the problem were not explicitly modeled as a function of time. This paper presents the modeling methodology developed to analyze these risks.

49 CFR 176.905 - Stowage of motor vehicles or mechanical equipment.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... (a) A vehicle or any mechanical equipment powered by an internal combustion engine, a fuel cell... equipment and there are no signs of leakage from the battery, engine, fuel cell, compressed gas cylinder or... fuel leaks and identifiable faults in the electrical system that could result in short circuit or other...

49 CFR 176.905 - Stowage of motor vehicles or mechanical equipment.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... (a) A vehicle or any mechanical equipment powered by an internal combustion engine, a fuel cell... equipment and there are no signs of leakage from the battery, engine, fuel cell, compressed gas cylinder or... fuel leaks and identifiable faults in the electrical system that could result in short circuit or other...

Temperature and Atomic Oxygen Effects on Helium Leak Rates of a Candidate Main Interface Seal

NASA Technical Reports Server (NTRS)

Penney, Nicholas; Wasowski, Janice L.; Daniels, Christopher C.

2011-01-01

Helium leak tests were completed to characterize the leak rate of a 54 in. diameter composite space docking seal design in support of the National Aeronautics and Space Administration s (NASA's) Low Impact Docking System (LIDS). The evaluated seal design was a candidate for the main interface seal on the LIDS, which would be compressed between two vehicles, while docked, to prevent the escape of breathable air from the vehicles and into the vacuum of space. Leak tests completed at nominal temperatures of -30, 20, and 50 C on untreated and atomic oxygen (AO) exposed test samples were examined to determine the influence of both test temperature and AO exposure on the performance of the composite seal assembly. Results obtained for untreated seal samples showed leak rates which increased with increased test temperature. This general trend was not observed in tests of the AO exposed specimens. Initial examination of collected test data suggested that AO exposure resulted in higher helium leak rates, however, further analysis showed that the differences observed in the 20 and 50 C tests between the untreated and AO exposed samples were within the experimental error of the test method. Lack of discernable trends in the test data prevented concrete conclusions about the effects of test temperature and AO exposure on helium leak rates of the candidate seal design from being drawn. To facilitate a comparison of the current test data with results from previous leak tests using air as the test fluid, helium leak rates were converted to air leak rates using standard conversion factors for viscous and molecular flow. Flow rates calculated using the viscous flow conversion factor were significantly higher than the experimental air leakage values, whereas values calculated using the molecular flow conversion factor were significantly lower than the experimentally obtained air leak rates. The difference in these sets of converted flow rates and their deviation from the experimentally obtained air leak rate data suggest that neither conversion factor can be used alone to accurately convert helium leak rates to equivalent air leak rates for the test seals evaluated in this study; other leak phenomena, including permeation, must also be considered.

29 CFR 1926.350 - Gas welding and cutting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... or valve protection caps to pry cylinders loose when frozen. Warm, not boiling, water shall be used... fuel gas cylinder is opened, there is found to be a leak around the valve stem, the valve shall be closed and the gland nut tightened. If this action does not stop the leak, the use of the cylinder shall...

DOE Office of Scientific and Technical Information (OSTI.GOV)

PIEPHO, M.G.

Four bounding accidents postulated for the K West Basin integrated water treatment system are evaluated against applicable risk evaluation guidelines. The accidents are a spray leak during fuel retrieval, spray leak during backflushing a hydrogen explosion, and a fire breaching filter vessel and enclosure. Event trees and accident probabilities are estimated. In all cases, the unmitigated dose consequences are below the risk evaluation guidelines.

Hydrogen and Gaseous Fuel Safety and Toxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee C. Cadwallader; J. Sephen Herring

2007-06-01

Non-traditional motor fuels are receiving increased attention and use. This paper examines the safety of three alternative gaseous fuels plus gasoline and the advantages and disadvantages of each. The gaseous fuels are hydrogen, methane (natural gas), and propane. Qualitatively, the overall risks of the four fuels should be close. Gasoline is the most toxic. For small leaks, hydrogen has the highest ignition probability and the gaseous fuels have the highest risk of a burning jet or cloud.

Test Report of Special Form Qualification Testing for the ORNL U ZipCan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, Oscar A.

This test report describes the special form testing activities performed on the two ZiPCans. One prototype test unit was subjected to the tests stipulated by 10 CFR 71.75 (d)(1)(i), ISO 2919:1999(E) Class 4 impact test, along with the leak rate test specified in 49 CFR 173.469(a)(4)(i). The other test unit was subjected to a leak rate test as specified in 173.469(a)(4)(i) and a heat test as specified in 49 CFR 173.469 (b)(4). Each test unit was leak tested before and after these respective tests. The leak rate tests performed were helium back-pressure tests and bubble tests, as specified in ANSImore » N14.5-2014.The measured leak rates were converted to standard condition leak rates as specified in ASTM E 493. The determined standardized leak rates from the test and calculation for both test units met the requirements for special form certification.« less

Empirical membrane lifetime model for heavy duty fuel cell systems

NASA Astrophysics Data System (ADS)

Macauley, Natalia; Watson, Mark; Lauritzen, Michael; Knights, Shanna; Wang, G. Gary; Kjeang, Erik

2016-12-01

Heavy duty fuel cells used in transportation system applications such as transit buses expose the fuel cell membranes to conditions that can lead to lifetime-limiting membrane failure via combined chemical and mechanical degradation. Highly durable membranes and reliable predictive models are therefore needed in order to achieve the ultimate heavy duty fuel cell lifetime target of 25,000 h. In the present work, an empirical membrane lifetime model was developed based on laboratory data from a suite of accelerated membrane durability tests. The model considers the effects of cell voltage, temperature, oxygen concentration, humidity cycling, humidity level, and platinum in the membrane using inverse power law and exponential relationships within the framework of a general log-linear Weibull life-stress statistical distribution. The obtained model is capable of extrapolating the membrane lifetime from accelerated test conditions to use level conditions during field operation. Based on typical conditions for the Whistler, British Columbia fuel cell transit bus fleet, the model predicts a stack lifetime of 17,500 h and a membrane leak initiation time of 9200 h. Validation performed with the aid of a field operated stack confirmed the initial goal of the model to predict membrane lifetime within 20% of the actual operating time.

Livermore study says oil leaks not severe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick, L.

The Petroleum Marketers Association of America (PMAA), which is working to reform the federal Leaking Underground Storage Tank program, got some strong ammunition last month. A study that the Lawrence Livermore National Laboratory performed for the California State Water Resources Control Board has found that the environmental threat of leaks is not as severe as formerly thought. The study said: such leaks rarely jeopardize drinking water; fuel hydrocarbons have limited impacts on health, the environment, and groundwater; and cleanups often are done contrary to the knowledge and experience gained from prior remediations. As a result of the study, Gov. Petemore » Wilson ordered California cleanups halted at sites more than 250 feet from drinking water supplies.« less

Pulsed Magnetic Welding for Advanced Core and Cladding Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Guoping; Yang, Yong

2013-12-19

To investigate a solid-state joining method, pulsed magnetic welding (PMW), for welding the advanced core and cladding steels to be used in Generation IV systems, with a specific application for fuel pin end-plug welding. As another alternative solid state welding technique, pulsed magnetic welding (PMW) has not been extensively explored on the advanced steels. The resultant weld can be free from microstructure defects (pores, non-metallic inclusions, segregation of alloying elements). More specifically, the following objectives are to be achieved: 1. To design a suitable welding apparatus fixture, and optimize welding parameters for repeatable and acceptable joining of the fuel pinmore » end-plug. The welding will be evaluated using tensile tests for lap joint weldments and helium leak tests for the fuel pin end-plug; 2 Investigate the microstructural and mechanical properties changes in PMW weldments of proposed advanced core and cladding alloys; 3. Simulate the irradiation effects on the PWM weldments using ion irradiation.« less

KSC-06pd0218

NASA Image and Video Library

2006-02-07

KENNEDY SPACE CENTER, FLA. - Pilot Steve Fossett (left) and Sir Richard Branson (right) talk with Virgin Atlantic GlobalFlyer team members about the fuel leak detected in the aircraft. Branson is chairman and founder of Virgin Atlantic. Fossett will pilot the GlobalFlyer on a record-breaking attempt by flying solo, non-stop without refueling, to surpass the current record for the longest flight of any aircraft. Fossett was expected to take off from the KSC SLF before the takeoff was postponed due to the fuel leak that appeared in the last moments of loading. The next planned takeoff attempt is 7 a.m. Feb. 8 from the SLF. Photo credit: NASA/Kim Shiflett

49 CFR 393.67 - Liquid fuel tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... section. The rules in this section apply to tanks containing or supplying fuel for the operation of... leak more than a total of one ounce by weight of fuel per minute in any position the tank assumes...) Drop test—(i) Procedure. Fill the tank with a quantity of water having a weight equal to the weight of...

46 CFR 56.97-38 - Initial service leak test (reproduces 137.7).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Initial service leak test (reproduces 137.7). 56.97-38... PIPING SYSTEMS AND APPURTENANCES Pressure Tests § 56.97-38 Initial service leak test (reproduces 137.7). (a) An initial service leak test and inspection is acceptable when other types of test are not...

Large-area imager of hydrogen leaks in fuel cells using laser-induced breakdown spectroscopy.

PubMed

Hori, M; Hayano, R S; Fukuta, M; Koyama, T; Nobusue, H; Tanaka, J

2009-10-01

We constructed a simple device, which utilized laser-induced breakdown spectroscopy to image H2 gas leaking from the surfaces of hydrogen fuel cells to ambient air. Nanosecond laser pulses of wavelength lambda=532 nm emitted from a neodymium-doped yttrium aluminum garnet laser were first compressed to a pulse length Deltat<1 ns using a stimulated Brillouin backscattering cell. Relay-imaging optics then focused this beam onto the H(2) leak and initiated the breakdown plasma. The Balmer-alpha (H-alpha) emission that emerged from this was collected with a 2-m-long macrolens assembly with a 90-mm-diameter image area, which covered a solid angle of approximately 1 x 10(-3)pi steradians seen from the plasma. The H-alpha light was isolated by two 100-mm-diameter interference filters with a 2 nm bandpass, and imaged by a thermoelectrically cooled charge-coupled device camera. By scanning the position of the laser focus, the spatial distribution of H2 gas over a 90-mm-diameter area was photographed with a spatial resolution of < or = 5 mm. Photoionization of the water vapor in the air caused a strong H-alpha background. By using pure N2 as a buffer gas, H2 leaks with rates of <1 cc/min were imaged. We also studied the possibilities of detecting He, Ne, or Xe gas leaks.

Analysis of temperature and pressure changes in liquefied natural gas (LNG) cryogenic tanks

NASA Astrophysics Data System (ADS)

Chen, Q.-S.; Wegrzyn, J.; Prasad, V.

2004-10-01

Liquefied natural gas (LNG) is being developed as a transportation fuel for heavy vehicles such as trucks and transit buses, to lessen the dependency on oil and to reduce greenhouse gas emissions. The LNG stations are properly designed to prevent the venting of natural gas (NG) from LNG tanks, which can cause evaporative greenhouse gas emissions and result in fluctuations of fuel flow and changes of fuel composition. Boil-off is caused by the heat added into the LNG fuel during the storage and fueling. Heat can leak into the LNG fuel through the shell of tank during the storage and through hoses and dispensers during the fueling. Gas from tanks onboard vehicles, when returned to LNG tanks, can add additional heat into the LNG fuel. A thermodynamic and heat transfer model has been developed to analyze different mechanisms of heat leak into the LNG fuel. The evolving of properties and compositions of LNG fuel inside LNG tanks is simulated. The effect of a number of buses fueled each day on the possible total fuel loss rate has been analyzed. It is found that by increasing the number of buses, fueled each day, the total fuel loss rate can be reduced significantly. It is proposed that an electric generator be used to consume the boil-off gas or a liquefier be used to re-liquefy the boil-off gas to reduce the tank pressure and eliminate fuel losses. These approaches can prevent boil-off of natural gas emissions, and reduce the costs of LNG as transportation fuel.

75 FR 54462 - Airworthiness Directives; Bombardier-Rotax GmbH 912 F Series and 912 S Series Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

... Airworthiness Directives; Bombardier-Rotax GmbH 912 F Series and 912 S Series Reciprocating Engines AGENCY... result in exceeding of the fuel pressure and might cause engine malfunction and/or massive fuel leakage... engine malfunction or a massive fuel leak. These conditions could cause loss of control of the airplane...

Can the intraoperative leak test prevent postoperative leakage of esophagojejunal anastomosis after total gastrectomy?

PubMed

Kanaji, Shingo; Ohyama, Masato; Yasuda, Takashi; Sendo, Hiroyoshi; Suzuki, Satoshi; Kawasaki, Kentaro; Tanaka, Kenichi; Fujino, Yasuhiro; Tominaga, Masahiro; Kakeji, Yoshihiro

2016-07-01

Anastomotic failures that cannot be detected during surgery often lead to postoperative leakage. There have been no detailed reports on the intraoperative leak test for esophagojejunal anastomosis. Our purpose was to investigate the utility of routine intraoperative leak testing to prevent postoperative anastomotic leakage after performing esophagojejunostomy. We prospectively performed routine air leak tests and reviewed the records of 185 consecutive patients with gastric cancer who underwent open total gastrectomy followed by esophagojejunostomy. A positive leak test was found for six patients (3.2 %). These patients with positive leak tests were subsequently treated with additional suturing, and they developed no postoperative anastomotic leakage. However, anastomotic leakage occurred in nine patients (4.9 %) with negative leak tests. A multivariate analysis demonstrated that a patient age >75 years and the surgeon's experience <30 cases were risk factors for anastomotic leakage. Intraoperative leak testing can detect some physical dehiscence, and additional suturing may prevent anastomotic leakage. However, it cannot prevent all anastomotic leakage caused by other factors, such as the surgeons' experience and patients' age.

Validation of Test Methods for Air Leak Rate Verification of Spaceflight Hardware

NASA Technical Reports Server (NTRS)

Oravec, Heather Ann; Daniels, Christopher C.; Mather, Janice L.

2017-01-01

As deep space exploration continues to be the goal of NASAs human spaceflight program, verification of the performance of spaceflight hardware becomes increasingly critical. Suitable test methods for verifying the leak rate of sealing systems are identified in program qualification testing requirements. One acceptable method for verifying the air leak rate of gas pressure seals is the tracer gas leak detector method. In this method, a tracer gas (commonly helium) leaks past the test seal and is transported to the leak detector where the leak rate is quantified. To predict the air leak rate, a conversion factor of helium-to-air is applied depending on the magnitude of the helium flow rate. The conversion factor is based on either the molecular mass ratio or the ratio of the dynamic viscosities. The current work was aimed at validating this approach for permeation-level leak rates using a series of tests with a silicone elastomer O-ring. An established pressure decay method with constant differential pressure was used to evaluate both the air and helium leak rates of the O-ring under similar temperature and pressure conditions. The results from the pressure decay tests showed, for the elastomer O-ring, that neither the molecular flow nor the viscous flow helium-to-air conversion factors were applicable. Leak rate tests were also performed using nitrogen and argon as the test gas. Molecular mass and viscosity based helium-to-test gas conversion factors were applied, but did not correctly predict the measured leak rates of either gas. To further this study, the effect of pressure boundary conditions was investigated. Often, pressure decay leak rate tests are performed at a differential pressure of 101.3 kPa with atmospheric pressure on the downstream side of the test seal. In space applications, the differential pressure is similar, but with vacuum as the downstream pressure. The same O-ring was tested at four unique differential pressures ranging from 34.5 to 137.9 kPa. Up to six combinations of upstream and downstream pressures for each differential pressure were compared. For a given differential pressure, the various combinations of upstream and downstream dry air pressures did not significantly affect the leak rate. As expected, the leak rate of the O-ring increased with increasing differential pressure. The results suggested that the current leak test pressure conditions, used to verify spacecraft sealing systems with elastomer seals, produce accurate values even though the boundary conditions do not model the space application.

Piping Connector

NASA Technical Reports Server (NTRS)

1994-01-01

In Stennis Space Center's Component Test Facility, piping lines carry rocket propellants and high pressure cryogenic fuels. When the lines are chilled to a pretest temperature of 400 degrees below zero, ordinary piping connectors can leak. Under contract to Stennis, Reflange, Inc. developed the T-Con connector, which included a secondary seal that tolerates severe temperature change. Because of the limited need for the large and expensive T-Con product, Reflange also developed the less costly E-Con, a smaller more compact design with the same technical advantages as the T-Con.

Woodbridge Research Facility Remedial Investigation/Feasibility Study; Remedial Investigation, Volume 1 - Text, Tables, and Figures

DTIC Science & Technology

1997-11-01

toxic form of organic mercury ( Eisler , 1987 ). The EEQs were calculated for both inorganic mercury and methyl mercury for robins and shrews to...always less than the toxicity of methylmercury, and methylmercury is the most toxic form of organic mercury ( Eisler , 1987 ), this assumption is likely to...The UST was installed in 1966 and was used to store #2 fuel oil. The tank was removed in 1986 or 1987 with no record of leak testing or soil

Areal extent of petroleum-related compounds from a gasoline and diesel-fuel leak in ground water at a site in Yakima, Washington, 1984-89

USGS Publications Warehouse

Wagner, R.J.

1995-01-01

A gasoline and diesel-fuel leak was discovered in the early 1980's at a service station in Yakima, Washington, and an attempt to recover the flee-floating petroleum product was unsuccessful. From 1984 through 1989, data were collected from observation wells drilled near the site of the leak and from nearby domestic wells during three separate studies. Between February 1985 and November 1986, benzene, toluene, xylenes, and other soluble compounds of petroleum origin were found at concentrations that exceeded standards for drinking water in all samples from observation wells within 300 feet of the service station. These compounds also were found in smaller concentrations in some samples from domestic wells as far as 1,500 feet downgradient of the service station. Concentrations of these soluble compounds in ground-water samples collected in March 1989 had decreased, and areal distribution of the compounds was smaller than when monitoring began in 1984.

KSC-06pd0217

NASA Image and Video Library

2006-02-07

KENNEDY SPACE CENTER, FLA. - Pilot Steve Fossett (facing camera, left) and Sir Richard Branson (second from right) talk with Virgin Atlantic GlobalFlyer team members about the fuel leak detected in the aircraft. Branson is chairman and founder of Virgin Atlantic. Steve Fossett will pilot the GlobalFlyer on a record-breaking attempt by flying solo, non-stop without refueling, to surpass the current record for the longest flight of any aircraft. Fossett was expected to take off from the KSC SLF before the takeoff was postponed due to the fuel leak that appeared in the last moments of loading. The next planned takeoff attempt is 7 a.m. Feb. 8 from the SLF. Photo credit: NASA/Kim Shiflett

Expert system for identification of simultaneous and sequential reactor fuel failures with gas tagging

DOEpatents

Gross, Kenny C.

1994-01-01

Failure of a fuel element in a nuclear reactor core is determined by a gas tagging failure detection system and method. Failures are catalogued and characterized after the event so that samples of the reactor's cover gas are taken at regular intervals and analyzed by mass spectroscopy. Employing a first set of systematic heuristic rules which are applied in a transformed node space allows the number of node combinations which must be processed within a barycentric algorithm to be substantially reduced. A second set of heuristic rules treats the tag nodes of the most recent one or two leakers as "background" gases, further reducing the number of trial node combinations. Lastly, a "fuzzy" set theory formalism minimizes experimental uncertainties in the identification of the most likely volumes of tag gases. This approach allows for the identification of virtually any number of sequential leaks and up to five simultaneous gas leaks from fuel elements.

Leak testing and repair of fusion devices

NASA Astrophysics Data System (ADS)

Kozman, T. A.

1983-06-01

The leak testing, reporting and vacuum leak repair techniques of the MPTF yin-yang number one magnet system, the world's largest superconducting magnet system, are discussed. Based on this experience, techniques are developed for testing and repairing leaks on the 42 MPTF-B magnets. The leak hunting techniques for the yin-yang magnet systems were applied to two helium circuits (the coil bundle and guard vacuum; both require helium flow for magnet cooldown). Additionally, during MPTF-B operation there are warm water plasma shields and piping that require leak checking.

On-line detection of key radionuclides for fuel-rod failure in a pressurized water reactor.

PubMed

Qin, Guoxiu; Chen, Xilin; Guo, Xiaoqing; Ni, Ning

2016-08-01

For early on-line detection of fuel rod failure, the key radionuclides useful in monitoring must leak easily from failing rods. Yield, half-life, and mass share of fission products that enter the primary coolant also need to be considered in on-line analyses. From all the nuclides that enter the primary coolant during fuel-rod failure, (135)Xe and (88)Kr were ultimately chosen as crucial for on-line monitoring of fuel-rod failure. A monitoring system for fuel-rod failure detection for pressurized water reactor (PWR) based on the LaBr3(Ce) detector was assembled and tested. The samples of coolant from the PWR were measured using the system as well as a HPGe γ-ray spectrometer. A comparison showed the method was feasible. Finally, the γ-ray spectra of primary coolant were measured under normal operations and during fuel-rod failure. The two peaks of (135)Xe (249.8keV) and (88)Kr (2392.1keV) were visible, confirming that the method is capable of monitoring fuel-rod failure on-line. Copyright © 2016 Elsevier Ltd. All rights reserved.

Vacuum decay container/closure integrity testing technology. Part 1. ASTM F2338-09 precision and bias studies.

PubMed

Wolf, Heinz; Stauffer, Tony; Chen, Shu-Chen Y; Lee, Yoojin; Forster, Ronald; Ludzinski, Miron; Kamat, Madhav; Godorov, Phillip; Guazzo, Dana Morton

2009-01-01

ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method is applicable for leak-testing rigid and semi-rigid non-lidded trays; trays or cups sealed with porous barrier lidding materials; rigid, nonporous packages; and flexible, nonporous packages. Part 1 of this series describes the precision and bias studies performed in 2008 to expand this method's scope to include rigid, nonporous packages completely or partially filled with liquid. Round robin tests using three VeriPac 325/LV vacuum decay leak testers (Packaging Technologies & Inspection, LLC, Tuckahoe, NY) were performed at three test sites. Test packages were 1-mL glass syringes. Positive controls had laser-drilled holes in the barrel ranging from about 5 to 15 microm in nominal diameter. Two different leak tests methods were performed at each site: a "gas leak test" performed at 250 mbar (absolute) and a "liquid leak test" performed at about 1 mbar (absolute). The gas leak test was used to test empty, air-filled syringes. All defects with holes > or = 5.0 microm and all no-defect controls were correctly identified. The only false negative result was attributed to a single syringe with a < 5.0-microm hole. Tests performed using a calibrated air leak supported a 0.10-cm3 x min(-1) (ccm) sensitivity limit (99/99 lower tolerance limit). The liquid leak test was used to test both empty, air-filled syringes and water-filled syringes. Test results were 100% accurate for all empty and water-filled syringes, both without holes and with holes (5, 10, and 15 microm). Tests performed using calibrated air flow leaks of 0, 0.05, and 0.10 ccm were also 100% accurate; data supported a 0.10-ccm sensitivity limit (99/99 lower tolerance limit). Quantitative differential pressure results strongly correlated to hole size using either liquid or gas vacuum decay leak tests. The higher vacuum liquid leak test gave noticeably higher pressure readings when water was present in the defect. Both the ASTM F2338-09 test method and the precision and bias study report are available by contacting ASTM International in West Conshohocken, PA, USA (www.astm.org).

Intelligent Chemical Sensor Systems for In-space Safety Applications

NASA Technical Reports Server (NTRS)

Hunter, G. W.; Xu, J. C.; Neudeck, P. G.; Makel, D. B.; Ward, B.; Liu, C. C.

2006-01-01

Future in-space and lunar operations will require significantly improved monitoring and Integrated System Health Management (ISHM) throughout the mission. In particular, the monitoring of chemical species is an important component of an overall monitoring system for space vehicles and operations. For example, in leak monitoring of propulsion systems during launch, inspace, and on lunar surfaces, detection of low concentrations of hydrogen and other fuels is important to avoid explosive conditions that could harm personnel and damage the vehicle. Dependable vehicle operation also depends on the timely and accurate measurement of these leaks. Thus, the development of a sensor array to determine the concentration of fuels such as hydrogen, hydrocarbons, or hydrazine as well as oxygen is necessary. Work has been on-going to develop an integrated smart leak detection system based on miniaturized sensors to detect hydrogen, hydrocarbons, or hydrazine, and oxygen. The approach is to implement Microelectromechanical Systems (MEMS) based sensors incorporated with signal conditioning electronics, power, data storage, and telemetry enabling intelligent systems. The final sensor system will be self-contained with a surface area comparable to a postage stamp. This paper discusses the development of this "Lick and Stick" leak detection system and it s application to In-Space Transportation and other Exploration applications.

N-16 monitors: Almaraz NPP experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adrada, J.

1997-02-01

Almaraz Nuclear Power Plant has installed N-16 monitors - one per steam generator - to control the leakage rate through the steam generator tubes after the application of leak before break (LBB) criteria for the top tube sheet (TTS). After several years of operation with the N-16 monitors, Almaraz NPP experience may be summarized as follows: N-16 monitors are very useful to follow the steam generator leak rate trend and to detect an incipient tube rupture; but they do not provide an exact absolute leak rate value, mainly when there are small leaks. The evolution of the measured N-16 leakmore » rates varies along the fuel cycle, with the same trend for the 3 steam generators. This behaviour is associated with the primary water chemistry evolution along the cycle.« less

Assessing Surgeon Behavior Change after Anastomotic Leak in Colorectal Surgery

PubMed Central

Simianu, Vlad V.; Basu, Anirban; Alfonso-Cristancho, Rafael; Thirlby, Richard C.; Flaxman, Abraham D.; Flum, David R.

2016-01-01

Background Recency effect suggests that people disproportionately value events from the immediate past when making decisions, but the extent of this impact on surgeons’ decisions is unknown. This study evaluates for recency effect in surgeons by examining use of preventative leak testing before and after colorectal operations with anastomotic leaks. Materials and Methods Prospective cohort of adult patients (≥18 years) undergoing elective colorectal operations at Washington State hospitals participating in the Surgical Care and Outcomes Assessment Program (2006–2013). The main outcome measure was surgeons’ change in leak testing from 6 months before to 6 months after an anastomotic leak occurred. Results Across 4,854 elective colorectal operations performed by 282 surgeons at 44 hospitals, there was a leak rate of 2.6% (n=124). The 40 leaks (32%) in which the anastomosis was not tested occurred across 25 surgeons. While the ability to detect an overall difference in use of leak testing was limited by small sample size, 9 (36%) of 25 surgeons increased their leak testing by 5 percent points or more after leaks in cases where the anastomosis was not tested. Surgeons who increased their leak testing more frequently performed operations for diverticulitis (45% vs 33%), more frequently began their cases laparoscopically (65% vs 37%), and had longer mean operative times (195±99 vs 148±87 minutes), all p<0.001. Conclusions Recency effect was demonstrated by only one-third of eligible surgeons. Understanding the extent to which clinical decisions may be influenced by recency effect may be important in crafting quality improvement initiatives that require clinician behavior change. PMID:27664886

40 CFR Appendix M to Part 51 - Recommended Test Methods for State Implementation Plans

Code of Federal Regulations, 2014 CFR

2014-07-01

..., and after the run with the cyclone removed. The cyclone is removed before the post-test leak-check to.... 4.1.4.3 Post-Test Leak-Check. A leak-check is required at the conclusion of each sampling run... disturbing the collected sample and use the following procedure to conduct a post-test leak-check. 4.1.4.3.1...

40 CFR Appendix M to Part 51 - Recommended Test Methods for State Implementation Plans

Code of Federal Regulations, 2013 CFR

2013-07-01

..., and after the run with the cyclone removed. The cyclone is removed before the post-test leak-check to.... 4.1.4.3 Post-Test Leak-Check. A leak-check is required at the conclusion of each sampling run... disturbing the collected sample and use the following procedure to conduct a post-test leak-check. 4.1.4.3.1...

40 CFR Appendix M to Part 51 - Recommended Test Methods for State Implementation Plans

Code of Federal Regulations, 2011 CFR

2011-07-01

..., and after the run with the cyclone removed. The cyclone is removed before the post-test leak-check to.... 4.1.4.3 Post-Test Leak-Check. A leak-check is required at the conclusion of each sampling run... disturbing the collected sample and use the following procedure to conduct a post-test leak-check. 4.1.4.3.1...

40 CFR Appendix M to Part 51 - Recommended Test Methods for State Implementation Plans

Code of Federal Regulations, 2012 CFR

2012-07-01

..., and after the run with the cyclone removed. The cyclone is removed before the post-test leak-check to.... 4.1.4.3 Post-Test Leak-Check. A leak-check is required at the conclusion of each sampling run... disturbing the collected sample and use the following procedure to conduct a post-test leak-check. 4.1.4.3.1...

10 CFR 35.2067 - Records of leaks tests and inventory of sealed sources and brachytherapy sources.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Records of leaks tests and inventory of sealed sources and... MATERIAL Records § 35.2067 Records of leaks tests and inventory of sealed sources and brachytherapy sources. (a) A licensee shall retain records of leak tests required by § 35.67(b) for 3 years. The records...

40 CFR 86.1337-96 - Engine dynamometer test run.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., dynamometer, and sampling system. (iii) Change filters, etc., and leak check as necessary. For a single... sample is lost. A separate leak check is needed. A leak check of a filter assembly that has only one seal ring in contact with the filter media will not detect a leak when tested under vacuum. A pressure leak...

40 CFR 86.1337-96 - Engine dynamometer test run.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., dynamometer, and sampling system. (iii) Change filters, etc., and leak check as necessary. For a single... sample is lost. A separate leak check is needed. A leak check of a filter assembly that has only one seal ring in contact with the filter media will not detect a leak when tested under vacuum. A pressure leak...

40 CFR 86.1337-96 - Engine dynamometer test run.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., dynamometer, and sampling system. (iii) Change filters, etc., and leak check as necessary. For a single... sample is lost. A separate leak check is needed. A leak check of a filter assembly that has only one seal ring in contact with the filter media will not detect a leak when tested under vacuum. A pressure leak...

40 CFR 86.1337-96 - Engine dynamometer test run.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., dynamometer, and sampling system. (iii) Change filters, etc., and leak check as necessary. For a single... sample is lost. A separate leak check is needed. A leak check of a filter assembly that has only one seal ring in contact with the filter media will not detect a leak when tested under vacuum. A pressure leak...

Routine intraoperative leak testing for sleeve gastrectomy: is the leak test full of hot air?

PubMed

Bingham, Jason; Lallemand, Michael; Barron, Morgan; Kuckelman, John; Carter, Preston; Blair, Kelly; Martin, Matthew

2016-05-01

Staple line leak after sleeve gastrectomy (SG) is a rare but dreaded complication with a reported incidence of 0% to 8%. Many surgeons routinely test the staple line with an intraoperative leak test (IOLT), but there is little evidence to validate this practice. In fact, there is a theoretical concern that the leak test may weaken the staple line and increase the risk of a postop leak. Retrospective review of all SGs performed over a 7-year period was conducted. Cases were grouped by whether an IOLT was performed, and compared for the incidence of postop staple line leaks. The ability of the IOLT for identifying a staple line defect and for predicting a postoperative leak was analyzed. Five hundred forty-two SGs were performed between 2007 and 2014. Thirteen patients (2.4%) developed a postop staple line leak. The majority of patients (n = 494, 91%) received an IOLT, including all 13 patients (100%) who developed a subsequent clinical leak. There were no (0%) positive IOLTs and no additional interventions were performed based on the IOLT. The IOLT sensitivity and positive predictive value were both 0%. There was a trend, although not significant, to increase leak rates when a routine IOLT was performed vs no routine IOLT (2.6% vs 0%, P = .6). The performance of routine IOLT after SG provided no actionable information, and was negative in all patients who developed a postoperative leak. The routine use of an IOLT did not reduce the incidence of postop leak, and in fact was associated with a higher leak rate after SG. Published by Elsevier Inc.

New instrumentation technologies for testing the bonding of sensors to solid materials

NASA Technical Reports Server (NTRS)

Hashemian, H. M.; Shell, C. S.; Jones, C. N.

1996-01-01

This report presents the results of a comprehensive research and development project that was conducted over a three-year period to develop new technologies for testing the attachment of sensors to solid materials for the following NASA applications: (1) testing the performance of composites that are used for the lining of solid rocket motor nozzles, (2) testing the bonding of surface-mounted platinum resistance thermometers that are used on fuel and oxidizer lines of the space shuttle to detect valve leaks by monitoring temperature, (3) testing the attachment of strain gages that are used in testing the performance of space shuttle main engines, and (4) testing the thermocouples that are used for determining the performance of blast tube liner material in solid rocket boosters.

Improved gas tagging and cover gas combination for nuclear reactor

DOEpatents

Gross, K.C.; Laug, M.T.

1983-09-26

The invention discloses the use of stable isotopes of neon and argon, sealed as tags in different cladding nuclear fuel elements to be used in a liquid metal fast breeder reactor. Cladding failure allows fission gases and these tag isotopes to escape and to combine with the cover gas. The isotopes are Ne/sup 20/, Ne/sup 21/ and Ne/sup 22/ and Ar/sup 36/, Ar/sup 38/ and Ar/sup 40/, and the cover gas is He. Serially connected cryogenically operated charcoal beds are used to clean the cover gas and to separate out the tags. The first or cover gas cleanup bed is held between 0 and -25/sup 0/C to remove the fission gases from the cover gas and tags, and the second or tag recovery system bed between -170 and -185/sup 0/C to isolate the tags from the cover gas. Spectrometric analysis is used to identify the specific tags that are recovered, and thus the specific leaking fuel element. By cataloging the fuel element tags to the location of the fuel elements in the reactor, the location of the leaking fuel element can then be determined.

Lightweight Vacuum Jacket for Cryogenic Insulation. Volume 1

NASA Technical Reports Server (NTRS)

Barclay, D. L.; Bell, J. E.; Brogren, E. W.; Straayer, J. W.

1975-01-01

The feasibility of producing a lightweight vacuum jacket using state-of-the-art technology and materials was examined. Design and analytical studies were made on a full-scale, orbital maneuvering system fuel tank. Preliminary design details were made for the tank assembly, including an optimized vacuum jacket and multilayer insulation system. A half-scale LH2 test model was designed and fabricated, and a force/stiffness proof test was conducted on the vacuum jacket. A vacuum leak rate of .000001 atmosphere ml of helium per second was measured, approximately 1500 hours of vacuum pressure were sustained, and 29 vacuum-pressure cycles were experienced prior to failure.

Lightweight Vacuum Jacket for Cryogenic Insulation - Appendices to Final Report. Volume 2

NASA Technical Reports Server (NTRS)

Barclay, D. L.; Bell, J. E.; Brogren, E. W.; Straayer, J. W.

1975-01-01

The feasibility is demonstrated of producing a lightweight vacuum jacket using state-of-the-art technology and materials. Design and analytical studies were made on an orbital maneuvering system fuel tank. Preliminary design details were completed for the tank assembly which included an optimized vacuum jacket and multilayered insulation system. A half-scale LH2 test model was designed and fabricated and a force/stiffness proof test was conducted on the vacuum jacket. A vacuum leak rate of 0.00001 was measured, approximately 1500 hours of vacuum pressure was sustained, and 29 vacuum pressure cycles were experienced prior to failure. For vol. 1, see N75-26192.

76 FR 78805 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 800 Series Turbofan Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-20

... rejected fuel tubes need to be replaced to avoid fuel leaks. Delta indicated that the On- wing Inspection... Revision Number Three commenters, American Airlines (American), Delta Airlines (Delta), and the Boeing... Revisions of the Service Bulletin One commenter, Delta, asked that engines previously inspected per Revision...

Pump-to-Wheels Methane Emissions from the Heavy-Duty Transportation Sector.

PubMed

Clark, Nigel N; McKain, David L; Johnson, Derek R; Wayne, W Scott; Li, Hailin; Akkerman, Vyacheslav; Sandoval, Cesar; Covington, April N; Mongold, Ronald A; Hailer, John T; Ugarte, Orlando J

2017-01-17

Pump-to-wheels (PTW) methane emissions from the heavy-duty (HD) transportation sector, which have climate change implications, are poorly documented. In this study, methane emissions from HD natural gas fueled vehicles and the compressed natural gas (CNG) and liquefied natural gas (LNG) fueling stations that serve them were characterized. A novel measurement system was developed to quantify methane leaks and losses. Engine related emissions were characterized from twenty-two natural gas fueled transit buses, refuse trucks, and over-the-road (OTR) tractors. Losses from six LNG and eight CNG stations were characterized during compression, fuel delivery, storage, and from leaks. Cryogenic boil-off pressure rise and pressure control venting from LNG storage tanks were characterized using theoretical and empirical modeling. Field and laboratory observations of LNG storage tanks were used for model development and evaluation. PTW emissions were combined with a specific scenario to view emissions as a percent of throughput. Vehicle tailpipe and crankcase emissions were the highest sources of methane. Data from this research are being applied by the authors to develop models to forecast methane emissions from the future HD transportation sector.

Assessing surgeon behavior change after anastomotic leak in colorectal surgery.

PubMed

Simianu, Vlad V; Basu, Anirban; Alfonso-Cristancho, Rafael; Thirlby, Richard C; Flaxman, Abraham D; Flum, David R

2016-10-01

Recency effect suggests that people disproportionately value events from the immediate past when making decisions, but the extent of this impact on surgeons' decisions is unknown. This study evaluates for recency effect in surgeons by examining use of preventative leak testing before and after colorectal operations with anastomotic leaks. Prospective cohort of adult patients (≥18 y) undergoing elective colorectal operations at Washington State hospitals participating in the Surgical Care and Outcomes Assessment Program (2006-2013). The main outcome measure was surgeons' change in leak testing from 6 mo before to 6 mo after an anastomotic leak occurred. Across 4854 elective colorectal operations performed by 282 surgeons at 44 hospitals, there was a leak rate of 2.6% (n = 124). The 40 leaks (32%) in which the anastomosis was not tested occurred across 25 surgeons. While the ability to detect an overall difference in use of leak testing was limited by small sample size, nine (36%) of 25 surgeons increased their leak testing by 5% points or more after leaks in cases where the anastomosis was not tested. Surgeons who increased their leak testing more frequently performed operations for diverticulitis (45% versus 33%), more frequently began their cases laparoscopically (65% versus 37%), and had longer mean operative times (195 ± 99 versus 148 ± 87 min), all P < 0.001. Recency effect was demonstrated by only one-third of eligible surgeons. Understanding the extent to which clinical decisions may be influenced by recency effect may be important in crafting quality improvement initiatives that require clinician behavior change. Copyright © 2016 Elsevier Inc. All rights reserved.

Examinations for leak tightness of actively cooled components in ITER and fusion devices

NASA Astrophysics Data System (ADS)

Hirai, T.; Barabash, V.; Carrat, R.; Chappuis, Ph; Durocher, A.; Escourbiac, F.; Merola, M.; Raffray, R.; Worth, L.; Boscary, J.; Chantant, M.; Chuilon, B.; Guilhem, D.; Hatchressian, J.-C.; Hong, S. H.; Kim, K. M.; Masuzaki, S.; Mogaki, K.; Nicolai, D.; Wilson, D.; Yao, D.

2017-12-01

Any leak in one of the ITER actively cooled components would cause significant consequences for machine operations; therefore, the risk of leak must be minimized as much as possible. In this paper, the strategy of examination to ensure leak tightness of the ITER internal components (i.e. examination of base materials, vacuum boundary joints and final components) and the hydraulic parameters for ITER internal components are summarized. The experiences of component tests, especially hot helium leak tests in recent fusion devices, were reviewed and the parameters were discussed. Through these experiences, it was confirmed that the hot He leak test was effective to detect small leak paths which were not always possible to detect by volumetric examination due to limited spatial resolution.

Liquid metal cooled nuclear reactor plant system

DOEpatents

Hunsbedt, Anstein; Boardman, Charles E.

1993-01-01

A liquid metal cooled nuclear reactor having a passive cooling system for removing residual heat resulting for fuel decay during reactor shutdown, or heat produced during a mishap. The reactor system is enhanced with sealing means for excluding external air from contact with the liquid metal coolant leaking from the reactor vessel during an accident. The invention also includes a silo structure which resists attack by leaking liquid metal coolant, and an added unique cooling means.

Prediction of failure pressure and leak rate of stress corrosion.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Majumdar, S.; Kasza, K.; Park, J. Y.

2002-06-24

An ''equivalent rectangular crack'' approach was employed to predict rupture pressures and leak rates through laboratory generated stress corrosion cracks and steam generator tubes removed from the McGuire Nuclear Station. Specimen flaws were sized by post-test fractography in addition to a pre-test advanced eddy current technique. The predicted and observed test data on rupture and leak rate are compared. In general, the test failure pressures and leak rates are closer to those predicted on the basis of fractography than on nondestructive evaluation (NDE). However, the predictions based on NDE results are encouraging, particularly because they have the potential to determinemore » a more detailed geometry of ligamented cracks, from which failure pressure and leak rate can be more accurately predicted. One test specimen displayed a time-dependent increase of leak rate under constant pressure.« less

Numerical investigation of VOC levels in the area of petrol stations.

PubMed

Kountouriotis, A; Aleiferis, P G; Charalambides, A G

2014-02-01

In the area of petrol stations several Volatile Organic Compounds (VOCs) leak into the atmosphere due to the evaporation of liquid fuels, especially of gasoline that is predominantly composed of light hydrocarbons. The aim of the present study is to investigate the spatial distribution of various VOCs when leaked into the atmosphere in the area of a petrol station. The study is based on numerical simulations. The effect of wind speed and direction, as well as of air temperature has been studied. Gasoline components of different properties have been studied (e.g. pentane, iso-octane, o-xylene, toluene, benzene), as well as ethanol that is considered a new fuel blend component that can be found in different fractions in new gasoline blends worldwide. The area of flammable cloud near the source of the leak is investigated for various atmospheric conditions taking into account the lower and higher flammable limits of each compound. Lastly, the exposure to gasoline vapour is studied taking into consideration the recommended occupational exposure limits of various organisations. © 2013 Elsevier B.V. All rights reserved.

Sensitivities of Soap Solutions in Leak Detection

NASA Technical Reports Server (NTRS)

Stuck, D.; Lam, D. Q.; Daniels, C.

1985-01-01

Document describes method for determining minimum leak rate to which soap-solution leak detectors sensitive. Bubbles formed at smaller leak rates than previously assumed. In addition to presenting test results, document discusses effects of joint-flange configurations, properties of soap solutions, and correlation of test results with earlier data.

Pharmaceutical container/closure integrity. I: Mass spectrometry-based helium leak rate detection for rubber-stoppered glass vials.

PubMed

Kirsch, L E; Nguyen, L; Moeckly, C S

1997-01-01

The development of mass spectrometry-based leak detection for pharmaceutical container integrity was undertaken to provide an alternative to microbial challenge testing. Standard 10-mL vials were modified to contain pinholes (0.5 to 10 microns) by affixing micropipettes with epoxy into 2-mm vial side wall holes. The absolute leak rate was determined using vials that were sealed in a tracer (helium) environment with butyl rubber stoppers and crimps. Alternatively leak rates were determined using vials that were sealed in room air and exposed to tracer under pressure (charging or bombing). Tracer leak rates were measured with mass spectrometry leak rate detectors. The absolute leak rate was correlated the squared nominal leak radius which suggested that the mode of gas flow through the glass pipette leaks was more turbulent than viscous even at low leak rates typically associated with viscous flow. The minimum observed absolute leak rate was about 10(-6.6) std cc/sec and was likely due to helium permeation through the rubber stoppers. Heat-stressed rubber stoppers did not affect the baseline absolute leak rate. Adsorption of helium tracer to the test unit surfaces was found to confound baseline leak rate measurement reliability but was eliminated as a source of variation by exposing the test units to ambient air for > or = 12 hours. The absolute leak rate and the leak rate measured after charging were related in a mathematically predictable way.

Routine Leak Testing in Colorectal Surgery in the Surgical Care and Outcomes Assessment Program

PubMed Central

Kwon, Steve; Morris, Arden; Billingham, Richard; Frankhouse, Joseph; Horvath, Karen; Johnson, Morrie; McNevin, Shane; Simons, Anthony; Symons, Rebecca; Steele, Scott; Thirlby, Richard; Whiteford, Mark; Flum, David R.

2014-01-01

Objective To evaluate the effect of routine anastomotic leak testing (performed to screen for leaks) vs selective testing (performed to evaluate for a suspected leak in a higher-risk or technically difficult anastomosis) on outcomes in colorectal surgery because the value of provocative testing of colorectal anastomoses as a quality improvement metric has yet to be determined. Design Observational, prospectively designed cohort study. Setting Data from Washington state’s Surgical Care and Outcomes Assessment Program (SCOAP). Patients Patients undergoing elective left-sided colon or rectal resections at 40 SCOAP hospitals from October 1, 2005, to December 31, 2009. Interventions Use of leak testing, distinguishing procedures that were performed at hospitals where leak testing was selective (<90% use) or routine (≥90% use) in a given calendar quarter. Main Outcome Measure Adjusted odds ratio of a composite adverse event (CAE) (unplanned postoperative intervention and/or in-hospital death) at routine testing hospitals. Results Among 3449 patients (mean [SD] age, 58.8[14.8] years; 55.0% women), the CAE rate was 5.5%. Provocative leak testing increased (from 56% in the starting quarter to 76% in quarter 16) and overall rates of CAE decreased (from 7.0% in the starting quarter to 4.6% in quarter 16; both P ≤ .01) over time. Among patients at hospitals that performed routine leak testing, we found a reduction of more than 75% in the adjusted risk of CAEs (odds ratio, 0.23; 95% CI, 0.05–0.99). Conclusion Routine leak testing of left-sided colorectal anastomoses appears to be associated with a reduced rate of CAEs within the SCOAP network and meets many of the criteria of a worthwhile quality improvement metric. PMID:22508778

Routine leak testing in colorectal surgery in the Surgical Care and Outcomes Assessment Program.

PubMed

Kwon, Steve; Morris, Arden; Billingham, Richard; Frankhouse, Joseph; Horvath, Karen; Johnson, Morrie; McNevin, Shane; Simons, Anthony; Symons, Rebecca; Steele, Scott; Thirlby, Richard; Whiteford, Mark; Flum, David R

2012-04-01

To evaluate the effect of routine anastomotic leak testing (performed to screen for leaks) vs selective testing (performed to evaluate for a suspected leak in a higher-risk or technically difficult anastomosis) on outcomes in colorectal surgery because the value of provocative testing of colorectal anastomoses as a quality improvement metric has yet to be determined. Observational, prospectively designed cohort study. Data from Washington state's Surgical Care and Outcomes Assessment Program (SCOAP). Patients undergoing elective left-sided colon or rectal resections at 40 SCOAP hospitals from October 1, 2005, to December 31, 2009. Use of leak testing, distinguishing procedures that were performed at hospitals where leak testing was selective (<90% use) or routine (≥ 90% use) in a given calendar quarter. Adjusted odds ratio of a composite adverse event (CAE) (unplanned postoperative intervention and/or in-hospital death) at routine testing hospitals. Among 3449 patients (mean [SD] age, 58.8 [14.8] years; 55.0% women), the CAE rate was 5.5%. Provocative leak testing increased (from 56% in the starting quarter to 76% in quarter 16) and overall rates of CAE decreased (from 7.0% in the starting quarter to 4.6% in quarter 16; both P ≤ .01) over time. Among patients at hospitals that performed routine leak testing, we found a reduction of more than 75% in the adjusted risk of CAEs (odds ratio, 0.23; 95% CI, 0.05-0.99). Routine leak testing of left-sided colorectal anastomoses appears to be associated with a reduced rate of CAEs within the SCOAP network and meets many of the criteria of a worthwhile quality improvement metric.

Artificial Leaks in Container Closure Integrity Testing: Nonlinear Finite Element Simulation of Aperture Size Originated by a Copper Wire Sandwiched between the Stopper and the Glass Vial.

PubMed

Nieto, Alejandra; Roehl, Holger; Brown, Helen; Adler, Michael; Chalus, Pascal; Mahler, Hanns-Christian

2016-01-01

Container closure integrity (CCI) testing is required by different regulatory authorities in order to provide assurance of tightness of the container closure system against possible contamination, for example, by microorganisms. Microbial ingress CCI testing is performed by incubation of the container closure system with microorganisms under specified testing conditions. Physical CCI uses surrogate endpoints, such as coloration by dye solution ingress or gas flow (helium leakage testing). In order to correlate microbial CCI and physical CCI test methods and to evaluate the methods' capability to detect a given leak, artificial leaks are being introduced into the container closure system in a variety of different ways. In our study, artificial leaks were generated using inserted copper wires between the glass vial opening and rubber stopper. However, the insertion of copper wires introduces leaks of unknown size and shape. With nonlinear finite element simulations, the aperture size between the rubber stopper and the glass vial was calculated, depending on wire diameter and capping force. The dependency of the aperture size on the copper wire diameter was quadratic. With the data obtained, we were able to calculate the leak size and model leak shape. Our results suggest that the size as well as the shape of the artificial leaks should be taken into account when evaluating critical leak sizes, as flow rate does not, independently, correlate to hole size. Capping force also affected leak size. An increase in the capping force from 30 to 70 N resulted in a reduction of the aperture (leak size) by approximately 50% for all wire diameters. From 30 to 50 N, the reduction was approximately 33%. Container closure integrity (CCI) testing is required by different regulatory authorities in order to provide assurance of tightness of the container closure system against contamination, for example, by microorganisms. Microbial ingress CCI testing is performed by incubation of the container closure system with microorganisms under specified testing conditions. Physical CCI uses surrogate endpoints, such as coloration by dye solution ingress or gas flow. In order to correlate microbial ingress CCI and physical CCI test methods and to evaluate the methods' capability to detect a given leak, artificially created defects (artificial leaks) are being introduced into the container closure system in a variety of different ways. In our study, artificial leaks were generated using inserted copper wires between the glass vial opening and rubber stopper. Up to date, the insertion of copper wires introduced leaks of unknown size and shape. With nonlinear finite element simulations, the effective aperture size between the rubber stopper and the glass vial was calculated, depending on wire diameter and capping force, and the leak shape was modelled. Our results suggest that the size as well as the shape of the artificial leaks should be taken into account when evaluating critical leak sizes, as flow rate does not, independently, correlate to the hole size. © PDA, Inc. 2016.

Study of Residual Gas Analyser (RGA) Response towards Known Leaks

NASA Astrophysics Data System (ADS)

Pathan, Firozkhan S.; Khan, Ziauddin; Semwal, Pratibha; George, Siju; Raval, Dilip C.; Thankey, Prashant L.; Manthena, Himabindu; Yuvakiran, Paravastu; Dhanani, Kalpesh R.

2012-11-01

Helium leak testing is the most versatile form of weld qualification test for any vacuum application. Almost every ultra-high vacuum (UHV) system utilizes this technique for insuring leak tightness for the weld joints as well as demountable joints. During UHV system under operational condition with many other integrated components, in-situ developed leaks identification becomes one of the prime aspect for maintaining the health of such system and for continuing the experiments onwards. Since online utilization of leak detector (LD) has many practical limitations, residual gas analyser (RGA) can be used as a potential instrument for online leak detection. For this purpose, a co-relation for a given leak rate between Leak Detector and RGA is experimentally established. This paper describes the experimental aspect and the relationship between leak detector and RGA.

Expert system for identification of simultaneous and sequential reactor fuel failures with gas tagging

DOEpatents

Gross, K.C.

1994-07-26

Failure of a fuel element in a nuclear reactor core is determined by a gas tagging failure detection system and method. Failures are catalogued and characterized after the event so that samples of the reactor's cover gas are taken at regular intervals and analyzed by mass spectroscopy. Employing a first set of systematic heuristic rules which are applied in a transformed node space allows the number of node combinations which must be processed within a barycentric algorithm to be substantially reduced. A second set of heuristic rules treats the tag nodes of the most recent one or two leakers as background'' gases, further reducing the number of trial node combinations. Lastly, a fuzzy'' set theory formalism minimizes experimental uncertainties in the identification of the most likely volumes of tag gases. This approach allows for the identification of virtually any number of sequential leaks and up to five simultaneous gas leaks from fuel elements. 14 figs.

Fuel leak detection apparatus for gas cooled nuclear reactors

DOEpatents

Burnette, Richard D.

1977-01-01

Apparatus is disclosed for detecting nuclear fuel leaks within nuclear power system reactors, such as high temperature gas cooled reactors. The apparatus includes a probe assembly that is inserted into the high temperature reactor coolant gaseous stream. The probe has an aperture adapted to communicate gaseous fluid between its inside and outside surfaces and also contains an inner tube for sampling gaseous fluid present near the aperture. A high pressure supply of noncontaminated gas is provided to selectively balance the pressure of the stream being sampled to prevent gas from entering the probe through the aperture. The apparatus includes valves that are operable to cause various directional flows and pressures, which valves are located outside of the reactor walls to permit maintenance work and the like to be performed without shutting down the reactor.

Detection of gas leakage

DOEpatents

Thornberg, Steven [Peralta, NM; Brown, Jason [Albuquerque, NM

2012-06-19

A method of detecting leaks and measuring volumes as well as an apparatus, the Power-free Pump Module (PPM), that is a self-contained leak test and volume measurement apparatus that requires no external sources of electrical power during leak testing or volume measurement, where the invention is a portable, pneumatically-controlled instrument capable of generating a vacuum, calibrating volumes, and performing quantitative leak tests on a closed test system or device, all without the use of alternating current (AC) power. Capabilities include the ability is to provide a modest vacuum (less than 10 Torr), perform a pressure rise leak test, measure the gas's absolute pressure, and perform volume measurements. All operations are performed through a simple rotary control valve which controls pneumatically-operated manifold valves.

Detection of gas leakage

DOEpatents

Thornberg, Steven M; Brown, Jason

2015-02-17

A method of detecting leaks and measuring volumes as well as a device, the Power-free Pump Module (PPM), provides a self-contained leak test and volume measurement apparatus that requires no external sources of electrical power during leak testing or volume measurement. The PPM is a portable, pneumatically-controlled instrument capable of generating a vacuum, calibrating volumes, and performing quantitative leak tests on a closed test system or device, all without the use of alternating current (AC) power. Capabilities include the ability is to provide a modest vacuum (less than 10 Torr) using a venturi pump, perform a pressure rise leak test, measure the gas's absolute pressure, and perform volume measurements. All operations are performed through a simple rotary control valve which controls pneumatically-operated manifold valves.

Pad stress tests with increasing load for the diagnosis of stress urinary incontinence.

PubMed

Rimstad, Liv; Larsen, Elsa Skjønhaug; Schiøtz, Hjalmar A; Kulseng-Hanssen, Sigurd

2014-09-01

The aim of the study was to test the ability of pad stress tests with increasing load (supine, jumping on the floor, and jumping on a trampoline) to document stress incontinence in subjectively stress incontinent women. In this prospective study 147 subjectively stress and mixed incontinent women performed consecutively the three pad stress tests with a bladder volume of 300 ml. Nineteen women performed a second trampoline pad stress test to test repeatability of the test. Nine continent women performed a trampoline pad stress test in order to determine if subjectively continent women would leak during the test. Seventy-two women (49%) leaked during the supine, 136 (93%) leaked during the jumping, and 146 (99%) leaked during the trampoline pad stress test. The differences between pad stress tests were significant with P < 0.005. Correlation between the two trampoline pad stress tests was high at 0.8. None of the nine continent women leaked during the trampoline pad stress test. The supine pad stress test has low sensitivity and is therefore often falsely negative. The jumping pad stress test is a simple test to perform and is satisfactory for everyday use. Subjectively stress incontinent women who do not leak during the jumping pad stress test may perform a trampoline pad stress test to document stress incontinence. The trampoline pad stress test is also simple to perform and detected leakage in 91% of the women who did not leak during the jumping pad stress test. © 2013 Wiley Periodicals, Inc.

Leak Rate Quantification Method for Gas Pressure Seals with Controlled Pressure Differential

NASA Technical Reports Server (NTRS)

Daniels, Christopher C.; Braun, Minel J.; Oravec, Heather A.; Mather, Janice L.; Taylor, Shawn C.

2015-01-01

An enhancement to the pressure decay leak rate method with mass point analysis solved deficiencies in the standard method. By adding a control system, a constant gas pressure differential across the test article was maintained. As a result, the desired pressure condition was met at the onset of the test, and the mass leak rate and measurement uncertainty were computed in real-time. The data acquisition and control system were programmed to automatically stop when specified criteria were met. Typically, the test was stopped when a specified level of measurement uncertainty was attained. Using silicone O-ring test articles, the new method was compared with the standard method that permitted the downstream pressure to be non-constant atmospheric pressure. The two methods recorded comparable leak rates, but the new method recorded leak rates with significantly lower measurement uncertainty, statistical variance, and test duration. Utilizing this new method in leak rate quantification, projects will reduce cost and schedule, improve test results, and ease interpretation between data sets.

77 FR 43374 - Biweekly Notice, Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... degrees Fahrenheit ([deg]F) as a consequence of inservice leak and hydrostatic testing, and as a consequence of scram time testing initiated in conjunction with an inservice leak or hydrostatic test, while... [Limited Conditions of Operation] 3.10.1, Inservice Leak and Hydrostatic Testing Operation Using...

Methane Leaks from Natural Gas Systems Follow Extreme Distributions.

PubMed

Brandt, Adam R; Heath, Garvin A; Cooley, Daniel

2016-11-15

Future energy systems may rely on natural gas as a low-cost fuel to support variable renewable power. However, leaking natural gas causes climate damage because methane (CH 4 ) has a high global warming potential. In this study, we use extreme-value theory to explore the distribution of natural gas leak sizes. By analyzing ∼15 000 measurements from 18 prior studies, we show that all available natural gas leakage data sets are statistically heavy-tailed, and that gas leaks are more extremely distributed than other natural and social phenomena. A unifying result is that the largest 5% of leaks typically contribute over 50% of the total leakage volume. While prior studies used log-normal model distributions, we show that log-normal functions poorly represent tail behavior. Our results suggest that published uncertainty ranges of CH 4 emissions are too narrow, and that larger sample sizes are required in future studies to achieve targeted confidence intervals. Additionally, we find that cross-study aggregation of data sets to increase sample size is not recommended due to apparent deviation between sampled populations. Understanding the nature of leak distributions can improve emission estimates, better illustrate their uncertainty, allow prioritization of source categories, and improve sampling design. Also, these data can be used for more effective design of leak detection technologies.

Methane Leaks from Natural Gas Systems Follow Extreme Distributions

DOE PAGES

Brandt, Adam R.; Heath, Garvin A.; Cooley, Daniel

2016-10-14

Future energy systems may rely on natural gas as a low-cost fuel to support variable renewable power. However, leaking natural gas causes climate damage because methane (CH 4) has a high global warming potential. In this study, we use extreme-value theory to explore the distribution of natural gas leak sizes. By analyzing ~15,000 measurements from 18 prior studies, we show that all available natural gas leakage datasets are statistically heavy-tailed, and that gas leaks are more extremely distributed than other natural and social phenomena. A unifying result is that the largest 5% of leaks typically contribute over 50% of themore » total leakage volume. While prior studies used lognormal model distributions, we show that lognormal functions poorly represent tail behavior. Our results suggest that published uncertainty ranges of CH 4 emissions are too narrow, and that larger sample sizes are required in future studies to achieve targeted confidence intervals. Additionally, we find that cross-study aggregation of datasets to increase sample size is not recommended due to apparent deviation between sampled populations. Finally, understanding the nature of leak distributions can improve emission estimates, better illustrate their uncertainty, allow prioritization of source categories, and improve sampling design. Also, these data can be used for more effective design of leak detection technologies.« less

Methane Leaks from Natural Gas Systems Follow Extreme Distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brandt, Adam R.; Heath, Garvin A.; Cooley, Daniel

Future energy systems may rely on natural gas as a low-cost fuel to support variable renewable power. However, leaking natural gas causes climate damage because methane (CH 4) has a high global warming potential. In this study, we use extreme-value theory to explore the distribution of natural gas leak sizes. By analyzing ~15,000 measurements from 18 prior studies, we show that all available natural gas leakage datasets are statistically heavy-tailed, and that gas leaks are more extremely distributed than other natural and social phenomena. A unifying result is that the largest 5% of leaks typically contribute over 50% of themore » total leakage volume. While prior studies used lognormal model distributions, we show that lognormal functions poorly represent tail behavior. Our results suggest that published uncertainty ranges of CH 4 emissions are too narrow, and that larger sample sizes are required in future studies to achieve targeted confidence intervals. Additionally, we find that cross-study aggregation of datasets to increase sample size is not recommended due to apparent deviation between sampled populations. Finally, understanding the nature of leak distributions can improve emission estimates, better illustrate their uncertainty, allow prioritization of source categories, and improve sampling design. Also, these data can be used for more effective design of leak detection technologies.« less

10 CFR 36.59 - Detection of leaking sources.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Detection of leaking sources. 36.59 Section 36.59 Energy... Irradiators § 36.59 Detection of leaking sources. (a) Each dry-source-storage sealed source must be tested for leakage at intervals not to exceed 6 months using a leak test kit or method approved by the Commission or...

Hermetic Seal Leak Detection Apparatus with Variable Size Test Chamber

NASA Technical Reports Server (NTRS)

Kelley, Anthony R. (Inventor)

2015-01-01

The present invention is a versatile hermetic seal leak detection apparatus for testing hermetically sealed containers and devices for leaks without the need to create a custom or specially manufactured testing chamber conforming to the dimensions of the specific object under test. The size of the testing chamber may be mechanically adjusted by the novel use of bellows to reduce and optimize the amount of gas space in a test chamber which surrounds the hermetically sealed object under test. The present invention allows the size of the test chamber to be selectively adjusted during testing to provide an optimum test chamber gas space. The present invention may be further adapted to isolate and test specific portions of the hermetically sealed object under test for leaks.

Method and apparatus for container leakage testing

DOEpatents

Kronberg, James W.

1995-01-01

An apparatus for use in one-hundred percent leak testing of food containers used in conjunction with a tracer gas. The apparatus includes a shell with entrance and exit air locks to create a controlled atmosphere through which a series of containers is conveyed by a conveyor belt. The pressure in the shell is kept lower than the pressure in the containers and the atmosphere is made to flow with the containers so that a tracer gas placed in the packages before sealing them will leak more readily, but the leaked tracer gas will remain associated with the leaking package as it moves through the shell. The leaks are detected with a sniffer probe in fluid communication with a gas chromatograph. The gas chromatograph issues a signal when it detects a leak to an ejector that will eject the leaking container from the conveyor. The system is timed so that the series of containers can move continuously into and out of the shell, past the probe and the ejector, without stopping, yet each package is tested for leaks and removed if leaking.

Mapping urban pipeline leaks: methane leaks across Boston.

PubMed

Phillips, Nathan G; Ackley, Robert; Crosson, Eric R; Down, Adrian; Hutyra, Lucy R; Brondfield, Max; Karr, Jonathan D; Zhao, Kaiguang; Jackson, Robert B

2013-02-01

Natural gas is the largest source of anthropogenic emissions of methane (CH(4)) in the United States. To assess pipeline emissions across a major city, we mapped CH(4) leaks across all 785 road miles in the city of Boston using a cavity-ring-down mobile CH(4) analyzer. We identified 3356 CH(4) leaks with concentrations exceeding up to 15 times the global background level. Separately, we measured δ(13)CH(4) isotopic signatures from a subset of these leaks. The δ(13)CH(4) signatures (mean = -42.8‰ ± 1.3‰ s.e.; n = 32) strongly indicate a fossil fuel source rather than a biogenic source for most of the leaks; natural gas sampled across the city had average δ(13)CH(4) values of -36.8‰ (± 0.7‰ s.e., n = 10), whereas CH(4) collected from landfill sites, wetlands, and sewer systems had δ(13)CH(4) signatures ~20‰ lighter (μ = -57.8‰, ± 1.6‰ s.e., n = 8). Repairing leaky natural gas distribution systems will reduce greenhouse gas emissions, increase consumer health and safety, and save money. Copyright © 2012 Elsevier Ltd. All rights reserved.

40 CFR 63.11094 - What are my recordkeeping requirements?

Code of Federal Regulations, 2010 CFR

2010-07-01

...: Test pressure; pressure or vacuum change, mm of water; time period of test; number of leaks found with... § 63.11092(f)(1) and periodic railcar bubble leak testing performed under § 63.11092(f)(2). (2) The... Certification Test—Method 27 or Periodic Railcar Bubble Leak Test Procedure. (ii) Cargo tank owner's name and...

40 CFR 53.52 - Leak check test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be verified at the highest and lowest pressures and temperatures used in the tests and shall be... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Leak check test. 53.52 Section 53.52... Leak check test. (a) Overview. In section 7.4.6 of 40 CFR part 50, appendix L, the sampler is required...

10 CFR 34.27 - Leak testing and replacement of sealed sources.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Leak testing and replacement of sealed sources. 34.27 Section 34.27 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.27 Leak testing and replacement...

10 CFR 34.27 - Leak testing and replacement of sealed sources.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Leak testing and replacement of sealed sources. 34.27 Section 34.27 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.27 Leak testing and replacement...

10 CFR 34.27 - Leak testing and replacement of sealed sources.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Leak testing and replacement of sealed sources. 34.27 Section 34.27 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.27 Leak testing and replacement...

10 CFR 34.27 - Leak testing and replacement of sealed sources.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Leak testing and replacement of sealed sources. 34.27 Section 34.27 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.27 Leak testing and replacement...

10 CFR 34.27 - Leak testing and replacement of sealed sources.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Leak testing and replacement of sealed sources. 34.27 Section 34.27 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.27 Leak testing and replacement...

Hermetic Seal Leak Detection Apparatus

NASA Technical Reports Server (NTRS)

Kelley, Anthony R. (Inventor)

2013-01-01

The present invention is a hermetic seal leak detection apparatus, which can be used to test for hermetic seal leaks in instruments and containers. A vacuum tight chamber is created around the unit being tested to minimize gas space outside of the hermetic seal. A vacuum inducing device is then used to increase the gas chamber volume inside the device, so that a slight vacuum is pulled on the unit being tested. The pressure in the unit being tested will stabilize. If the stabilized pressure reads close to a known good seal calibration, there is not a leak in the seal. If the stabilized pressure reads closer to a known bad seal calibration value, there is a leak in the seal. The speed of the plunger can be varied and by evaluating the resulting pressure change rates and final values, the leak rate/size can be accurately calculated.

Pharmaceutical container/closure integrity. II: The relationship between microbial ingress and helium leak rates in rubber-stoppered glass vials.

PubMed

Kirsch, L E; Nguyen, L; Moeckly, C S; Gerth, R

1997-01-01

Helium leak rate measurements were quantitatively correlated to the probability of microbial ingress for rubber-stoppered glass vials subjected to immersion challenge. Standard 10-mL tubing glass vials were modified by inserting micropipettes of various sizes (0.1 to 10 microns nominal diameter) into a side wall hole and securing them with epoxy. Butyl rubber closures and aluminum crimps were used to seal the vials. The test units were sealed in a helium-filled glove bag, then the absolute helium leak rates were determined. The test units were disassembled, filled with media, resealed, and autoclaved. The test units were thermally treated to eliminate airlocks within the micropipette lumen and establish a liquid path between microbial challenge media and the test units' contents. Microbial challenge was performed by immersing the test units in a 35 degrees C bath containing magnesium ion and 8 to 10 logs of viable P. diminuta and E. coli for 24 hours. The test units were then incubated at 35 degrees C for an additional 13 days. Microbial ingress was detected by turbidity and plating on blood agar. The elimination of airlocks was confirmed by the presence of magnesium ions in the vial contents by atomic absorption spectrometry. A total of 288 vials were subjected to microbial challenge testing. Those test units whose contents failed to show detectable magnesium ions were eliminated from further analysis. At large leak rates, the probability of microbial ingress approached 100% and at very low leak rates microbial ingress rates were 0%. A dramatic increase in microbial failure occurred in the leak rate region 10(-4.5) to 10(-3) std cc/sec, which roughly corresponded to leak diameters ranging from 0.4 to 2 microns. Below a leak rate of 10(-4.5) std cc/sec the microbial failure rate was < 10%. The critical leak rate in our studies, i.e. the value below which microbial ingress cannot occur because the leak is too small, was observed to be between 10(-5) and 10(-5.8) std cc/sec, which corresponds to an approximate leak diameter of 0.2-0.3 micron.

Test program to provide confidence in liquid oxygen cooling of hydrocarbon fueled rocket thrust chambers

NASA Technical Reports Server (NTRS)

Armstrong, E. S.

1986-01-01

An experimental program has been planned at the NASA Lewis Research Center to build confidence in the feasibility of liquid oxygen cooling for hydrocarbon fueled rocket engines. Although liquid oxygen cooling has previously been incorporated in test hardware, more runtime is necessary to gain confidence in this concept. In the previous tests, small oxygen leaks developed at the throat of the thrust chamber and film cooled the hot-gas side of the chamber wall without resulting in catastrophic failure. However, more testing is necessary to demonstrate that a catastrophic failure would not occur if cracks developed further upstream between the injector and the throat, where the boundary layer has not been established. Since under normal conditions cracks are expected to form in the throat region of the thrust chamber, cracks must be initiated artificially in order to control their location. Several methods of crack initiation are discussed in this report. Four thrust chambers, three with cracks and one without, should be tested. The axial location of the cracks should be varied parametrically. Each chamber should be instrumented to determine the effects of the cracks, as well as the overall performance and durability of the chambers.

Color Changing Hydrogen Sensors

NASA Technical Reports Server (NTRS)

Roberson, Luke B.; Williams, Martha; Captain, Janine E.; Mohajeri, Nahid; Raissi, Ali

2015-01-01

During the Space Shuttle Program, one of the most hazardous operation that occurred was the loading of liquid hydrogen (LH2) during fueling operations of the spacecraft. Due to hydrogen's low explosive limit, any amount leaked could lead to catastrophic event. Hydrogen's chemical properties make it ideal as a rocket fuel; however, the fuel is deemed unsafe for most commercial use because of the inability to easily detect the gas leaking. The increased use of hydrogen over traditional fossil fuels would reduce greenhouse gases and America's dependency on foreign oil. Therefore a technology that would improve safety at NASA and in the commercial sector while creating a new economic sector would have a huge impact to NASA's mission. The Chemochromic Detector for sensing hydrogen gas leakage is a color-changing detector that is useful in any application where it is important to know not only the presence but also the location of the hydrogen gas leak. This technology utilizes a chemochromicpigment and polymer matrix that can be molded or spun into rigid or pliable shapes useable in variable temperature environments including atmospheres of inert gas, hydrogen gas, or mixtures of gases. A change in color of the detector material indicates where gaseous hydrogen leaks are occurring. The irreversible sensor has a dramatic color change from beige to dark grey and remains dark grey after exposure. A reversible pigment changes from white to blue in the presence of hydrogen and reverts back to white in the presence of oxygen. Both versions of the sensor's pigments were comprised of a mixture of a metal oxide substrate and a hydro-chromic compound (i.e., the compound that changed color in the presence of hydrogen) and immediately notified the operator of the presence of low levels of hydrogen. The detector can be used in a variety of formats including paint, tape, caulking, injection molded parts, textiles and fabrics, composites, and films. This technology brings numerous benefits over the traditional hydrogen sensors: The technology has excellent temperature stability (4K to 373 K), it can be used in cryogenic fluid applications, it is easy to apply and remove; it requires no power to operate; it has a quick response time; the leak points can be detected visually or electronically; it is nonhazardous, thus environmentally friendly; it can be reversible or irreversible; it does not require on-site monitoring; has a long shelf life; the detector is very durable; and the technology is inexpensive to manufacture.

Numerical Modeling, Thermomechanical Testing, and NDE Procedures for Prediction of Microcracking Induced Permeability of Cryogenic Composites

NASA Technical Reports Server (NTRS)

Noh, Jae; Whitcomb, John; Oh, Bongtaek; Lagoudas, Dimitris; Maslov, Konstatin; Ganpatyre, Atul; Kinra, Vikram

2003-01-01

Reusable Space Vehicles will include light cryogenic composite fuel tanks that must not leak excessively even after multiple launches. Damage in cryogenic composite fuel tanks induced during manufacturing and advanced by thermomechanical cycling can accelerate leakage of the propellant. Whether the leakage exceeds tolerable levels depends on many factors, including pressure gradients, microcrack density, other damage such as delamination, connectivity of the cracks, residual stresses from manufacture, service-induced stresses from thermal and mechanical loads, and composite lay-up. Although it is critical to experimentally characterize permeability during various thermal and mechanical load histories, optimal design depends on having analytical models that can predict the effect of various parameters on performance. Our broad goal is to develop such models that are experimentally validated by destructive and non-destructive evaluation means.

40 CFR 63.428 - Reporting and recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-07-01

...; pressure or vacuum change, mm of water; time period of test; number of leaks found with instrument; and... facility as follows: (1) Annual certification testing performed under § 63.425(e) and railcar bubble leak...)); Annual Certification Test—Internal Vapor Valve (§ 63.425(e)(2)); Leak Detection Test (§ 63.425(f...

A primary standard for the calibration of sniffer test leak devices

NASA Astrophysics Data System (ADS)

Jousten, Karl; Becker, Ute

2009-10-01

Test leaks with a gas flow to atmospheric pressure are often called sniffer test leaks. They are used to calibrate leak detectors for sniffing applications. Sniffer test leaks need calibration against a standard. A primary standard for the calibration of sniffer test leaks with relatively low measurement uncertainties is described. It is assured that the measurement result is traceable to the relevant SI units and that there is a well-known and complete measurement uncertainty budget. The measurement range of the system is from 4 × 10-11 mol s-1 (corresponding to 10-4 Pa l s-1 at 23 °C) to 4 × 10-9 mol s-1 (10-2 Pa l s-1 at 23 °C), which is the most often needed range in industry of around 1 g loss per year of the cooling agent R134a. The temperature where the calibration can be carried out may vary from 18 °C to 30 °C. The flow rate of any test gas not condensing in this temperature range can be measured.

Leak testing in parenteral packaging: establishment of direct correlation between helium leak rate measurements and microbial ingress for two different leak types.

PubMed

Morrical, Bradley D; Goverde, Marcel; Grausse, Jean; Gerwig, Tanja; Vorgrimler, Lothar; Morgen, Rachel; Büttiker, Jean-Pierre

2007-01-01

A direct test method using helium leak detection was developed to determine microbial ingress in parenteral vial/rubber closure systems. The purpose of this study was to establish a direct correlation between the helium leak rate and the presence of ingress when vials were submersed under pressure in a broth of bacteria. Results were obtained for two different types of leaks: microholes that have been laser-drilled into thin metal plates, and thin copper wire that was placed between the rubber closure and the glass vial's sealing surface. The results from the microholes showed that the helium leak rate was a function of the square of the hole diameter and fit well with theoretical calculations. The relationship with the wire gave a far more complex dependence and was not modeled theoretically. Comparison with the microbial challenge showed that for microholes a lower size limit was found to be 2 microm with a corresponding leak rate of 1.4 x 10(-3) mbarl/s. For the fine wire experiment the lower limit was 15-microm wire and a corresponding leak rate of 1.3 x 10(-5) mbarl/s. From these tests a safe, lower limit, leak rate was established.

Analysis of Ignition Testing on K-West Basin Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Abrefah; F.H. Huang; W.M. Gerry

Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basinmore » into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).« less

10 CFR 300.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... these forms of distributed energy. Base period means a period of 1-4 years used to derive the average... fossil fuels or other materials, such as HFC leaks from refrigeration, SF6 from electrical power...

10 CFR 300.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... these forms of distributed energy. Base period means a period of 1-4 years used to derive the average... fossil fuels or other materials, such as HFC leaks from refrigeration, SF6 from electrical power...

10 CFR 300.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... these forms of distributed energy. Base period means a period of 1-4 years used to derive the average... fossil fuels or other materials, such as HFC leaks from refrigeration, SF6 from electrical power...

10 CFR 300.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... these forms of distributed energy. Base period means a period of 1-4 years used to derive the average... fossil fuels or other materials, such as HFC leaks from refrigeration, SF6 from electrical power...

10 CFR 300.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... these forms of distributed energy. Base period means a period of 1-4 years used to derive the average... fossil fuels or other materials, such as HFC leaks from refrigeration, SF6 from electrical power...

Vacuum decay container closure integrity leak test method development and validation for a lyophilized product-package system.

PubMed

Patel, Jayshree; Mulhall, Brian; Wolf, Heinz; Klohr, Steven; Guazzo, Dana Morton

2011-01-01

A leak test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method was developed and validated for container-closure integrity verification of a lyophilized product in a parenteral vial package system. This nondestructive leak test method is intended for use in manufacturing as an in-process package integrity check, and for testing product stored on stability in lieu of sterility tests. Method development and optimization challenge studies incorporated artificially defective packages representing a range of glass vial wall and sealing surface defects, as well as various elastomeric stopper defects. Method validation required 3 days of random-order replicate testing of a test sample population of negative-control, no-defect packages and positive-control, with-defect packages. Positive-control packages were prepared using vials each with a single hole laser-drilled through the glass vial wall. Hole creation and hole size certification was performed by Lenox Laser. Validation study results successfully demonstrated the vacuum decay leak test method's ability to accurately and reliably detect those packages with laser-drilled holes greater than or equal to approximately 5 μm in nominal diameter. All development and validation studies were performed at Whitehouse Analytical Laboratories in Whitehouse, NJ, under the direction of consultant Dana Guazzo of RxPax, LLC, using a VeriPac 455 Micro Leak Test System by Packaging Technologies & Inspection (Tuckahoe, NY). Bristol Myers Squibb (New Brunswick, NJ) fully subsidized all work. A leak test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method was developed and validated to detect defects in stoppered vial packages containing lyophilized product for injection. This nondestructive leak test method is intended for use in manufacturing as an in-process package integrity check, and for testing product stored on stability in lieu of sterility tests. Test method validation study results proved the method capable of detecting holes laser-drilled through the glass vial wall greater than or equal to 5 μm in nominal diameter. Total test time is less than 1 min per package. All method development and validation studies were performed at Whitehouse Analytical Laboratories in Whitehouse, NJ, under the direction of consultant Dana Guazzo of RxPax, LLC, using a VeriPac 455 Micro Leak Test System by Packaging Technologies & Inspection (Tuckahoe, NY). Bristol Myers Squibb (New Brunswick, NJ) fully subsidized all work.

Experience with helium leak and thermal shocks test of SST-1 cryo components

NASA Astrophysics Data System (ADS)

Sharma, Rajiv; Nimavat, Hiren; Srikanth, G. L. N.; Bairagi, Nitin; Shah, Pankil; Tanna, V. L.; Pradhan, S.

2012-11-01

A steady state superconducting Tokamak SST-1 is presently under its assembly stage at the Institute for Plasma Research. The SST-1 machine is a family of Superconducting SC coils for both Toroidal field and Poloidal Field. An ultra high vacuum compatible vacuum vessel, placed in the bore of the TF coils, houses the plasma facing components. A high vacuum cryostat encloses all the SC coils and the vacuum vessel. Liquid Nitrogen (LN2) cooled thermal shield between the vacuum vessel & SC coils as well as between cryostat and the SC coils. There are number of crucial cryogenic components as Electrical isolators, 80 K thermal shield, Cryogenic flexible hose etc., which have to be passed the performance validation tests as part of fulfillment of the stringent QA/QC before incorporated in the main assembly. The individual leak tests of components at RT as well as after thermal cycle from 300 K to 77 K ensure us to make final overall leak proof system. These components include, Large numbers of Electrical Isolators for Helium as well as LN2 services, Flexible Bellows and Hoses for Helium as well as LN2 services, Thermal shock tests of large numbers of 80 K Bubble shields In order to validate the helium leak tightness of these components, we have used the calibrated mass spectrometer leak detector (MSLD) at 300 K, 77 K and 4.2. Since it is very difficult to locate the leaks, which are appearing at rather lower temperatures e.g. less than 20 K, We have invented different approaches to resolve the issue of such leaks. This paper, in general describes the design of cryogenic flexible hose, assembly, couplings for leak testing, test method and techniques of thermal cycles test at 77 K inflow conditions and leak testing aspects of different cryogenic components. The test results, the problems encountered and its solutions techniques are discussed.

Aerospace Payloads Leak Test Methodology

NASA Technical Reports Server (NTRS)

Lvovsky, Oleg; Grayson, Cynthia M.

2010-01-01

Pressurized and sealed aerospace payloads can leak on orbit. When dealing with toxic or hazardous materials, requirements for fluid and gas leakage rates have to be properly established, and most importantly, reliably verified using the best Nondestructive Test (NDT) method available. Such verification can be implemented through application of various leak test methods that will be the subject of this paper, with a purpose to show what approach to payload leakage rate requirement verification is taken by the National Aeronautics and Space Administration (NASA). The scope of this paper will be mostly a detailed description of 14 leak test methods recommended.

Payload and Components Real-Time Automated Test System (PACRATS), Data Acquisition of Leak Rate and Pressure Data Test Procedure

NASA Technical Reports Server (NTRS)

Rinehart, Maegan L.

2011-01-01

The purpose of this activity is to provide the Mechanical Components Test Facility (MCTF) with the capability to obtain electronic leak test and proof pressure data, Payload and Components Real-time Automated Test System (PACRATS) data acquisition software will be utilized to display real-time data. It will record leak rates and pressure/vacuum level(s) simultaneously. This added functionality will provide electronic leak test and pressure data at specified sampling frequencies. Electronically stored data will provide ES61 with increased data security, analysis, and accuracy. The tasks performed in this procedure are to verify PACRATS only, and are not intended to provide verifications for MCTF equipment.

Solid oxide fuel cell generator

DOEpatents

Draper, Robert; George, Raymond A.; Shockling, Larry A.

1993-01-01

A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

Performance analysis and an assessment of operational issues of Ya-21U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paramonov, D.V.; El-Genk, M.S.

1996-03-01

Extensive testing of the Soviet made TOPAZ-II space nuclear power system unit designated {open_quote}{open_quote}Ya-21U{close_quote}{close_quote} was conducted both in the USSR (1989{endash}1990) and in the US (August 1993 to March 1995). The unit underwent a total of 15 tests for a cumulative test/operation time of almost 8000 hours. These tests included steady-state operation at different power levels, fast startups and power optimizations. Leaks were detected in some of the Thermionic Fuel Elements (TFEs) after the first test in the US. These leaks that facilitated air incursion into the interelectrode gap caused operational changes in both electric power and conversion efficiency andmore » changed the optimum cesium pressure and load voltage. Additional changes in operational performance were detected following shock and vibration tests performed in August 1994. Test data was examined and analyzed to assess the performance of not only individual TFEs, and also the whole Ya-21U unit, and identify causes for measured operational performance changes; most probable causes were identified and discussed. The Ya-21U unit remained operational throughout extensive testing for 8000 hours at conditions far exceeding the design limits of the TOPAZ-II system. No single TFE was damaged during testing and measured operational performance changes were uniform among working section TFEs. In addition to providing a unique knowledge base for future development and operation of thermionic power systems, the test results testify to the reliability and ruggedness of the TOPAZ-II system design. {copyright} {ital 1996 American Institute of Physics.}« less

Failure Pressure and Leak Rate of Steam Generator Tubes With Stress Corrosion Cracks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Majumdar, S.; Kasza, K.; Park, J.Y.

2002-07-01

This paper illustrates the use of an 'equivalent rectangular crack' approach to predict leak rates through laboratory generated stress corrosion cracks. A comparison between predicted and observed test data on rupture and leak rate from laboratory generated stress corrosion cracks are provided. Specimen flaws were sized by post-test fractography in addition to pre-test advanced eddy current technique. The test failure pressures and leak rates are shown to be closer to those predicted on the basis of fractography than on NDE. However, the predictions based on NDE results are encouraging, particularly because they have the potential to determine a more detailedmore » geometry of ligamentous cracks from which more accurate predictions of failure pressure and leak rate can be made in the future. (authors)« less

10 CFR 34.67 - Records of leak testing of sealed sources and devices containing depleted uranium.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Records of leak testing of sealed sources and devices containing depleted uranium. 34.67 Section 34.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL... Requirements § 34.67 Records of leak testing of sealed sources and devices containing depleted uranium. Each...

10 CFR 34.67 - Records of leak testing of sealed sources and devices containing depleted uranium.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Records of leak testing of sealed sources and devices containing depleted uranium. 34.67 Section 34.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL... Requirements § 34.67 Records of leak testing of sealed sources and devices containing depleted uranium. Each...

10 CFR 34.67 - Records of leak testing of sealed sources and devices containing depleted uranium.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Records of leak testing of sealed sources and devices containing depleted uranium. 34.67 Section 34.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL... Requirements § 34.67 Records of leak testing of sealed sources and devices containing depleted uranium. Each...

10 CFR 34.67 - Records of leak testing of sealed sources and devices containing depleted uranium.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Records of leak testing of sealed sources and devices containing depleted uranium. 34.67 Section 34.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL... Requirements § 34.67 Records of leak testing of sealed sources and devices containing depleted uranium. Each...

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR HARVARD PM IMPACTOR CALIBRATION AND LEAK TESTING (UA-L-7.1)

EPA Science Inventory

The purpose of this SOP is to describe the procedures for the periodic calibration and leak testing of Harvard particulate matter (PM) impactor units. This procedure applies directly to the calibration and leak testing of Harvard PM impactor units used during the Arizona NHEXAS ...

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR HARVARD PM IMPACTOR CALIBRATION AND LEAK TESTING (UA-L-7.1)

EPA Science Inventory

The purpose of this SOP is to describe the procedures for the periodic calibration and leak testing of Harvard particulate matter (PM) impactor units. This procedure applies directly to the calibration and leak testing of Harvard PM impactor units used during the Arizona NHEXAS ...

10 CFR 34.67 - Records of leak testing of sealed sources and devices containing depleted uranium.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Records of leak testing of sealed sources and devices containing depleted uranium. 34.67 Section 34.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL... Requirements § 34.67 Records of leak testing of sealed sources and devices containing depleted uranium. Each...

Hazardous Materials Hazard Analysis, Portland, Oregon.

DTIC Science & Technology

1981-06-01

combustible liquids, primarily petroleum products such as gasoline and fuel oil . Although less prevalent, compressed flammable gases (such as liquid...magnitude when hazardous materials are involved. -- Texas City, Texas, 1947--A ship being loaded with ammonium nitrate exploded, killing 468 people...An overturned gasoline or home heating fuel oil tanker or natural gas leak which does not ignite would be a Level 1 emergency. Level 2: A spill or

40 CFR 65.115 - Standards: Closed vent systems and control devices; or emissions routed to a fuel gas system or...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Standards: Closed vent systems and control devices; or emissions routed to a fuel gas system or process. 65.115 Section 65.115 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Equipment Leaks § 65.115 Standards:...

White gauze test: a novel technique in preventing post-hepatectomy bile leak.

PubMed

Yugasaravanan, K; Affirul, C A; Zamri, Z; Azlanudin, A; Bong, J J

Post-hepatectomy bile leak may lead to undesired morbidity. Multiple methods have been employed to identify this leak but can be inconclusive and taxing. This novel white gauze test is a simple and reliable method. This is a prospective study performed from January 2010 until March 2011. All open hepatic resection were included. Dry white gauze is compressed onto the transected surface and observed for bile staining. The leaking duct is repaired immediately upon detection. The process is repeated until negative. Drain was removed on postoperative day-5. Post-operative bile leak is defined as: 1. Bilirubin concentration of the drain fluid is 3 times or higher than serum; 2. Presence of intra-abdominal bile collection on imaging and upon drainage; 3. Bile leak demonstrated on postoperative cholangiography. 42 patients were recruited. Seven (16.7%) patients were cirrhotic with Child-Pugh A. White gauze test were positive for intra-operative bile leaks in 29 patients (70%), which were primarily repaired. As a result, there was no postoperative bile leak in this series. One mortality was detected in this series due to postoperative pancreatic fistula and multi organ failure. The White Gauze Test is a useful method for the prevention of bile leakage after hepatic resection. It is safe, quick and cheap.

SIXTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W.

2011-08-31

A series of experiments to monitor the aging performance of Viton{reg_sign} GLT O-rings used in the Model 9975 package has been ongoing for seven years at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 F. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 F. High temperature aging continues formore » 33 GLT O-ring fixtures at 200-300 F. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 F and higher temperatures, and in 7 fixtures aging at 300 F. No failures have yet been observed in GLT O-ring fixtures aging at 200 F for 41-60 months, which is still bounding to O-ring temperatures during storage in K-Area Complex (KAC). Based on expectations that the fixtures aging at 200 F will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging within the past year at an intermediate temperature of 270 F, with hopes that they may leak before the 200 F fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200-300 F. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 F. No failures have yet been observed in GLT-S O-ring fixtures aging at 200-300 F for up to 26 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the Orings displayed a compression set ranging from 51-96%. This is greater than seen to date for packages inspected during KAC field surveillance (24% average). For GLT O-rings, separate service life estimates have been made based on the O-ring fixture leak test data and based on compression stress relaxation (CSR) data. These two predictive models show reasonable agreement at higher temperatures (350-400 F). However, at 300 F, the room temperature leak test failures to date experienced longer aging times than predicted by the CSR-based model. This suggests that extrapolations of the CSR model predictions to temperatures below 300 F will provide a conservative prediction of service life relative to the leak rate criterion. Leak test failure data at lower temperatures are needed to verify this apparent trend. Insufficient failure data exist currently to perform a similar comparison for GLT-S O-rings. Aging and periodic leak testing will continue for the remaining fixtures.« less

Apparatus for detecting leaks

DOEpatents

Booth, Eugene T.

1976-02-24

A method and apparatus for determining the position of and estimating the size of leaks in an evacuating apparatus comprising the use of a testing gas such as helium or hydrogen flowing around said apparatus whereby the testing gas will be drawn in at the site of any leaks.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.; JOHNS, B.R.

1999-12-21

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

2000-02-28

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping Instrumentation and Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

1999-08-11

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

JOHNS, B.R.

1999-05-05

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

1999-10-26

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

JOHNS, B.R.; KOCH, M.R.

2000-01-28

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping Instrumentation and Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Biogeochemical assessment of natural attenuation of JP-4-contaminated ground water in the presence of fluorinated surfactants.

PubMed

Levine, A D; Libelo, E L; Bugna, G; Shelley, T; Mayfield, H; Stauffer, T B

1997-12-22

The biogeochemistry of the natural attenuation of petroleum-contaminated ground water was investigated in a field study. The focus of the study was a fire training site located on Tyndall Air Force Base in Florida. The site has been used by the Air Force for approximately 11 years in fire fighting exercises. An on-site above-ground tank of JP-4 provided fuel for setting controlled fires for the exercises. Various amounts of water and aqueous film forming foams (AFFF) were applied to extinguish the fires. The sources of contamination included leaks from pipelines transporting the fuel, leaks from an oil/water separator and runoff and percolation from the fire fighting activities. Previous investigations had identified jet fuel contamination at the site, however, no active remediation efforts have been conducted to date. The goal of this study was to use biogeochemical monitoring data to delineate redox zones within the site and to identify evidence of natural attenuation of JP-4 contamination. In addition to identifying several hydrocarbon metabolites, fluorinated surfactants (AFFF) were detected down-gradient of the hydrocarbon plume.

What is the optimal management of an intra-operative air leak in a colorectal anastomosis?

PubMed

Mitchem, J B; Stafford, C; Francone, T D; Roberts, P L; Schoetz, D J; Marcello, P W; Ricciardi, R

2018-02-01

An airtight anastomosis on intra-operative leak testing has been previously demonstrated to be associated with a lower risk of clinically significant postoperative anastomotic leak following left-sided colorectal anastomosis. However, to date, there is no consistently agreed upon method for management of an intra-operative anastomotic leak. Therefore, we powered a noninferiority study to determine whether suture repair alone was an appropriate strategy for the management of an intra-operative air leak. This is a retrospective cohort analysis of prospectively collected data from a tertiary care referral centre. We included all consecutive patients with left-sided colorectal or ileorectal anastomoses and evidence of air leak during intra-operative leak testing. Patients were excluded if proximal diversion was planned preoperatively, a pre-existing proximal diversion was present at the time of surgery or an anastomosis was ultimately unable to be completed. The primary outcome measure was clinically significant anastomotic leak, as defined by the Surgical Infection Study Group at 30 days. From a sample of 2360 patients, 119 had an intra-operative air leak during leak testing. Sixty-eight patients underwent suture repair alone and 51 underwent proximal diversion or anastomotic reconstruction. The clinically significant leak rate was 9% (6/68; 95% CI: 2-15%) in the suture repair alone arm and 0% (0/51) in the diversion or reconstruction arm. Suture repair alone does not meet the criteria for noninferiority for the management of intra-operative air leak during left-sided colorectal anastomosis. Further repair of intra-operative air leak by suture repair alone should be reconsidered given these findings. Colorectal Disease © 2017 The Association of Coloproctology of Great Britain and Ireland.

21 CFR 800.20 - Patient examination gloves and surgeons' gloves; sample plans and test method for leakage defects...

Code of Federal Regulations, 2010 CFR

2010-04-01

... examination and by a water leak test method, using 1,000 milliliters (ml) of water. (i) Units examined. Each... inches up the fill tube.) (iii) Leak test examination. Immediately after adding the water, examine the glove for water leaks. Do not squeeze the glove; use only minimum manipulation to spread the fingers to...

Detecting well casing leaks in Bangladesh using a salt spiking method

USGS Publications Warehouse

Stahl, M.O.; Ong, J.B.; Harvey, C.F.; Johnson, C.D.; Badruzzaman, A.B.M.; Tarek, M.H.; VanGeen, A.; Anderson, J.A.; Lane, J.W.

2014-01-01

We apply fluid-replacement logging in arsenic-contaminated regions of Bangladesh using a low-cost, down-well fluid conductivity logging tool to detect leaks in the cased section of wells. The fluid-conductivity tool is designed for the developing world: it is lightweight and easily transportable, operable by one person, and can be built for minimal cost. The fluid-replacement test identifies leaking casing by comparison of fluid conductivity logs collected before and after spiking the wellbore with a sodium chloride tracer. Here, we present results of fluid-replacement logging tests from both leaking and non-leaking casing from wells in Araihazar and Munshiganj, Bangladesh, and demonstrate that the low-cost tool produces measurements comparable to those obtained with a standard geophysical logging tool. Finally, we suggest well testing procedures and approaches for preventing casing leaks in Bangladesh and other developing countries.

Detecting well casing leaks in Bangladesh using a salt spiking method.

PubMed

Stahl, M O; Ong, J B; Harvey, C F; Johnson, C D; Badruzzaman, A B M; Tarek, M H; van Geen, A; Anderson, J A; Lane, J W

2014-09-01

We apply fluid-replacement logging in arsenic-contaminated regions of Bangladesh using a low-cost, down-well fluid conductivity logging tool to detect leaks in the cased section of wells. The fluid-conductivity tool is designed for the developing world: it is lightweight and easily transportable, operable by one person, and can be built for minimal cost. The fluid-replacement test identifies leaking casing by comparison of fluid conductivity logs collected before and after spiking the wellbore with a sodium chloride tracer. Here, we present results of fluid-replacement logging tests from both leaking and non-leaking casing from wells in Araihazar and Munshiganj, Bangladesh, and demonstrate that the low-cost tool produces measurements comparable to those obtained with a standard geophysical logging tool. Finally, we suggest well testing procedures and approaches for preventing casing leaks in Bangladesh and other developing countries. © 2014, National Ground Water Association.

40 CFR 65.117 - Alternative means of emission limitation: Batch processes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Equipment Leaks § 65.117 Alternative means... section provide the options of pressure testing or monitoring the equipment for leaks. The owner or... pressure-tested for leaks before regulated material is first fed to the equipment and the equipment is...

The Predictive Value of Coefficient of PCT × BG for Anastomotic Leak in Esophageal Carcinoma Patients With ARDS After Esophagectomy.

PubMed

Li, Huan; Wang, Daofeng; Wei, Wenxiao; Ouyang, Lamei; Lou, Ning

2017-01-01

Anastomotic leak was a potentially severe life-threatening complication of esophagectomy, which drew attention in consequence of progressive dyspnea until acute respiratory distress syndrome (ARDS) due to the early asymptomatic presentation. Respiratory failure, caused by ARDS as the severe presentation of anastomotic leak, is the most common organ failure. CRP (C-reactive protein), procalcitonin (PCT), and Blood G (BG) test are the sensitivity markers for inflammatory, sepsis, and fungemia, respectively. Early recognition and intervention treatment of anastomotic leak may alleviate complication and improve outcome. We retrospectively analyzed 71 patients, accepting mechanical ventilation support because of ARDS as the complication after radical resection of esophagus cancer. Clinical data were collected from the patients' electronic medical records, including their clinically hematological examination, drainage fluid cultures, and sputum culture. Accord to appearance of anastomotic leak or not, all patients were divided into 2 groups, leak group and no-leak group. Inflammatory markers, such as CRP, PCT, and the coefficient of BG and PCT, were significantly different between the 2 groups. Respiratory index, white blood cell, hemoglobin (HBG), platelet (PLT), and other clinical factors were not significantly different between the 2 groups. Receiver operating characteristic curves were constructed to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve for various cutoff levels of several factors. Blood G tests presented the better predicting value for anastomotic leak. Blood G tests and PCT should be tested after esophagectomy. The coefficient of PCT and BG (>260) is of great significance, and clinical value to predict anastomotic leak for patients with postesophagectomy ARDS, early PCT and BG test, and especially, dynamic variation may alleviate complication and improve outcome.

Method Of Making Closed End Ceramic Fuel Cell Tubes

DOEpatents

Borglum, Brian P.

2002-04-30

A method of manufacturing closed end ceramic fuel cell tubes with improved properties and higher manufacturing yield is disclosed. The method involves bonding an unfired cap to a hollow unfired tube to form a compound joint. The assembly is then fired to net shape without subsequent machining. The resultant closed end tube is superior in that it provides a leak-tight seal and its porosity is substantially identical to that of the tube wall. The higher manufacturing yield associated with the present method decreases overall fuel cell cost significantly.

Analysis of Underground Storage Tanks System Materials to Increased Leak Potential Associated with E15 Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kass, Michael D; Theiss, Timothy J; Janke, Christopher James

2012-07-01

The Energy Independence and Security Act (EISA) of 2007 was enacted by Congress to move the nation toward increased energy independence by increasing the production of renewable fuels to meet its transportation energy needs. The law establishes a new renewable fuel standard (RFS) that requires the nation to use 36 billion gallons annually (2.3 million barrels per day) of renewable fuel in its vehicles by 2022. Ethanol is the most widely used renewable fuel in the US, and its production has grown dramatically over the past decade. According to EISA and RFS, ethanol (produced from corn as well as cellulosicmore » feedstocks) will make up the vast majority of the new renewable fuel requirements. However, ethanol use limited to E10 and E85 (in the case of flex fuel vehicles or FFVs) will not meet this target. Even if all of the E0 gasoline dispensers in the country were converted to E10, such sales would represent only about 15 billion gallons per year. If 15% ethanol, rather than 10% were used, the potential would be up to 22 billion gallons. The vast majority of ethanol used in the United States is blended with gasoline to create E10, that is, gasoline with up to 10% ethanol. The remaining ethanol is sold in the form of E85, a gasoline blend with as much as 85% ethanol that can only be used in FFVs. Although DOE remains committed to expanding the E85 infrastructure, that market will not be able to absorb projected volumes of ethanol in the near term. Given this reality, DOE and others have begun assessing the viability of using intermediate ethanol blends as one way to transition to higher volumes of ethanol. In October of 2010, the EPA granted a partial waiver to the Clean Air Act allowing the use of fuel that contains up to 15% ethanol for the model year 2007 and newer light-duty motor vehicles. This waiver represents the first of a number of actions that are needed to move toward the commercialization of E15 gasoline blends. On January 2011, this waiver was expanded to include model year 2001 light-duty vehicles, but specifically prohibited use in motorcycles and off-road vehicles and equipment. UST stakeholders generally consider fueling infrastructure materials designed for use with E0 to be adequate for use with E10, and there are no known instances of major leaks or failures directly attributable to ethanol use. It is conceivable that many compatibility issues, including accelerated corrosion, do arise and are corrected onsite and, therefore do not lead to a release. However, there is some concern that higher ethanol concentrations, such as E15 or E20, may be incompatible with current materials used in standard gasoline fueling hardware. In the summer of 2008, DOE recognized the need to assess the impact of intermediate blends of ethanol on the fueling infrastructure, specifically located at the fueling station. This includes the dispenser and hanging hardware, the underground storage tank, and associated piping. The DOE program has been co-led and funded by the Office of the Biomass Program and Vehicle Technologies Program with technical expertise from the Oak Ridge National Laboratory (ORNL) and the National Renewable Energy Laboratory (NREL). The infrastructure material compatibility work has been supported through strong collaborations and testing at Underwriters Laboratories (UL). ORNL performed a compatibility study investigating the compatibility of fuel infrastructure materials to gasoline containing intermediate levels of ethanol. These results can be found in the ORNL report entitled Intermediate Ethanol Blends Infrastructure Materials Compatibility Study: Elastomers, Metals and Sealants (hereafter referred to as the ORNL intermediate blends material compatibility study). These materials included elastomers, plastics, metals and sealants typically found in fuel dispenser infrastructure. The test fuels evaluated in the ORNL study were SAE standard test fuel formulations used to assess material-fuel compatibility within a relatively short timeframe. Initially, these material studies included test fuels of Fuel C, CE10a, CE17a, and CE25a. The CE17a test fuel was selected to represent E15 since surveys have shown that the actual ethanol upper limit can be as high as 17%. Later, CE50a and CE85a test fuels were added to the investigation and these results are being compiled for a follow-on report to be published in 2012. Fuel C was used as the baseline reference and is a 50:50 blend of isooctane and toluene. This particular composition was used to represent premium-grade gasoline and was also used as the base fuel for the ethanol blends, where it is denoted by 'C' in the fuel name. The level of ethanol is represented by the number following the letter E. Therefore a 10% blend of ethanol in Fuel C is written as CE10a, where 'a' represents an aggressive formulation of the ethanol that contains water, NaCl, acetic and sulfuric acids per the SAE J1681 protocol.« less

A multicenter study of routine versus selective intraoperative leak testing for sleeve gastrectomy.

PubMed

Bingham, Jason; Kaufman, Jedediah; Hata, Kai; Dickerson, James; Beekley, Alec; Wisbach, Gordon; Swann, Jacob; Ahnfeldt, Eric; Hawkins, Devon; Choi, Yong; Lim, Robert; Martin, Matthew

2017-09-01

Staple line leaks after sleeve gastrectomy are dreaded complications. Many surgeons routinely perform an intraoperative leak test (IOLT) despite little evidence to validate the reliability, clinical benefit, and safety of this procedure. To determine the efficacy of IOLT and if routine use has any benefit over selective use. Eight teaching hospitals, including private, university, and military facilities. A multicenter, retrospective analysis over a 5-year period. The efficacy of the IOLT for identifying unsuspected staple line defects and for predicting postoperative leaks was evaluated. An anonymous survey was also collected reflecting surgeons' practices and beliefs regarding IOLT. From January 2010 through December 2014, 4284 patients underwent sleeve gastrectomy. Of these, 37 patients (.9%) developed a postoperative leak, and 2376 patients (55%) received an IOLT. Only 2 patients (0.08%) had a positive finding. Subsequently, 21 patients with a negative IOLT developed a leak. IOLT demonstrated a sensitivity of only 8.7%. There was a nonsignificant trend toward increased leak rates when an IOLT was performed versus when IOLT was not performed. Leak rates were not statistically different between centers that routinely perform IOLT versus those that selectively perform IOLT. Routine IOLT had very poor sensitivity and was negative in 91% of patients who later developed postoperative leaks. The use of IOLT was not associated with a decrease in the incidence of postoperative leaks, and routine IOLT had no benefit over selective leak testing. IOLT should not be used as a quality indicator or "best practice" for bariatric surgery. Published by Elsevier Inc.

Hazardous Gas Leak Analysis in the Space Shuttle

NASA Technical Reports Server (NTRS)

Barile, Ronald G.

1991-01-01

Helium tests of the main propulsion system in the Space Shuttle and on hydrogen leaks are examined. The hazardous gas detection system (HGDS) in the mobile launch pad uses mass spectrometers (MS) to monitor the shuttle environment for leaks. The mass spectrometers are fed by long tubes to sample gas from the payload bay, mid-body, aft engine compartment, and external tank. The purpose is to improve the HGDS, especially in its potential for locating cryogen leaks. Pre-existing leak data was analyzed for transient information to determine if the leak location could be pinpointed from test data. A rapid response leak detection experiment was designed, built, and tested. Large eddies and vortices were visually seen with Schlieren imaging, and they were detected in the time plots of the various instruments. The response time of the MS was found in the range of 0.05 to 0.1 sec. Pulsed concentration waves were clearly detected at 25 cycles per sec by spectral analysis of MS data. One conclusion is that the backup HGDS sampling frequency should be increased above the present rate of 1 sample per second.

Leak test fixture and method for using same

DOEpatents

Hawk, Lawrence S.

1976-01-01

A method and apparatus are provided which are especially useful for leak testing seams such as an end closure or joint in an article. The test does not require an enclosed pressurized volume within the article or joint section to be leak checked. A flexible impervious membrane is disposed over an area of the seamed surfaces to be leak checked and sealed around the outer edges. A preselected vacuum is applied through an opening in the membrane to evacuate the area between the membrane and the surface being leak checked to essentially collapse the membrane to conform to the article surface or joined adjacent surfaces. A pressure differential is concentrated at the seam bounded by the membrane and only the seam experiences a pressure differential as air or helium molecules are drawn into the vacuum system through a leak in the seam. A helium detector may be placed in a vacuum exhaust line from the membrane to detect the helium. Alternatively, the vacuum system may be isolated at a preselected pressure and leaks may be detected by a subsequent pressure increase in the vacuum system.

A Burke-Schumann Analysis of Dual-Flame Structure Supported by a Burning Droplet

NASA Technical Reports Server (NTRS)

Nayagam, V.; Dietrich, D.; Williams, F. A.

2016-01-01

Droplet combustion experiments carried out onboard the International Space Station (ISS), using pure fuels and fuel mixtures, have shown that quasi-steady burning can be sustained by a non-traditional flame configuration, namely a "cool flame" burning in the "partial-burning" regime where both fuel and oxygen leak through the low-temperature controlled flame-sheet. Recent experiments involving large, bi-component fuel (n-decane and hexanol, 50/50 by volume) droplets at elevated pressures show that the visible, hot flame becomes extremely weak while the burning rate remains relatively high, suggesting the possibility of simultaneous presence of "cool" and "hot" flames of roughly equal importance. The radiant output from these bi-component droplets is relatively high and cannot be accounted for only by the presence of a visible hot-flame. In this analysis we explore the theoretical possibility of a dual-flame structure, where one flame lies close to the droplet surface called the "cool-flame," and other farther away from the droplet surface, termed the "hot-flame." A Burke-Schumann analysis of this dual-structure seems to indicate such flame structures are possible over a narrow range of initial conditions. Theoretical results can be compared against available experimental data for pure and bi-component fuel droplet combustion to test how realistic the model may be.

40 CFR 65.144 - Fuel gas systems and processes to which storage vessel, transfer rack, or equipment leak...

Code of Federal Regulations, 2010 CFR

2010-07-01

...; (ii) Transformed by chemical reaction into materials that are not regulated materials; (iii... section for a storage vessel, the owner or operator shall prepare a design evaluation (or engineering...

PREDICTING DIVING PLUME BEHAVIOR

EPA Science Inventory

The United States Environmental Protection Agency has responded to a number of multi media environmental issues surrounding the use of methyl tertiary butyl ether (MTBE) and other fuel oxygenates. In Region 5, MTBE from various sources - but mainly from leaking underground stora...

Leak test adapter for containers

DOEpatents

Hallett, Brian H.; Hartley, Michael S.

1996-01-01

An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

SEVENTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W.

2012-08-30

A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23more » GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 54-72 months, which is still bounding to O-ring temperatures during storage in K-Area Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 30 - 36 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the O-rings displayed a compression set ranging from 51 – 96%. This is greater than seen to date for any packages inspected during KAC field surveillance (24% average). For GLT O-rings, separate service life estimates have been made based on the O-ring fixture leak test data and based on compression stress relaxation (CSR) data. These two predictive models show reasonable agreement at higher temperatures (350 – 400 ºF). However, at 300 ºF, the room temperature leak test failures to date experienced longer aging times than predicted by the CSRbased model. This suggests that extrapolations of the CSR model predictions to temperatures below 300 ºF will provide a conservative prediction of service life relative to the leak rate criterion. Leak test failure data at lower temperatures are needed to verify this apparent trend. Insufficient failure data exist currently to perform a similar comparison for GLT-S O-rings. Aging and periodic leak testing will continue for the remaining PCV O-ring fixtures.« less

Seal Integrity of Selected Fuzes as Measured by Three Leak Test Methods

DTIC Science & Technology

1976-09-01

the worst fuze from the seal standpoint. The M503A-2 fuze body is made from a cast aluminum alloy . The casting process leaves voids which, after...leak resistance of the joint. WDU4A/A The design of this fuze depends upon ultrasonic welding to seal lid to case. The specified leak test merely...test is probably one of the better leakage tests from an effectiveness standpoint. However, from lot quantities of 690 and 480, reject rates of 20% were

Closeup View of the Space Shuttle Main Engine (SSME) 2044 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up View of the Space Shuttle Main Engine (SSME) 2044 mounted in a SSME Engine Handler in the SSME processing Facility at Kennedy Space Center. This view shows SSME 2044 with its expansion nozzle removed and an Engine Leak-Test Plug is set in the throat of the Main Combustion Chamber in the approximate center of the image, the insulated, High-Pressure Fuel Turbopump sits below that and the Low Pressure Oxidizer Turbopump Discharge Duct sits towards the top of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

SSV Launch Monitoring Strategies: HGDS Design Implementation Through System Maturity

NASA Technical Reports Server (NTRS)

Shoemaker, Marc D.; Crimi, Thomas

2010-01-01

With over 500,000 gallons of liquid hydrogen and liquid oxygen, it is of vital importance to monitor the space shuttle vehicle (SSV) from external tank (ET) load through launch. The Hazardous Gas Detection System (HGDS) was installed as the primary system responsible for monitoring fuel leaks within the orbiter and ET. The HGDS was designed to obtain the lowest possible detection limits with the best resolution while monitoring the SSV for any hydrogen, helium, oxygen, or argon as the main requirement. The HGDS is a redundant mass spectrometer used for real-time monitoring during Power Reactant Storage and Distribution (PRSD) load and ET load through launch or scrub. This system also performs SSV processing leak checks of the Tail Service Mast (TSM) umbilical quick disconnects (QD's), Ground Umbilical Carrier Plate (GUCP) QD's and supports auxiliary power unit (APU) system tests. From design to initial implementation and operations, the HGDS has evolved into a mature and reliable launch support system. This paper will discuss the operational challenges and lessons learned from facing design deficiencies, validation and maintenance efforts, life cycle issues, and evolving requirements

Leak rate measurements for satellite subsystems and residual gas analysis during space environment tests. [thermal vacuum and solar simulation tests

NASA Technical Reports Server (NTRS)

Nuss, H. E.

1975-01-01

The measuring and evaluation procedure for the determination of leak rates of satellite subsystems with a quadrupole mass spectrometer, and the results of the residual gas analysis are described. The method selected for leak rate determination was placing the system into a vacuum chamber and furnishing the chamber with a mass spectrometer and calibrated leaks. The residual gas of a thermal vacuum test facility, in which the thermal balance test radiation input was simulated by a heated canister, was analyzed with the mass spectrometer in the atomic mass unit range up to 300 amu. In addition to the measurements during the space environment tests, mass spectrometric studies were performed with samples of spacecraft materials. The studies were carried out during tests for the projects HELIOS, AEROS B and SYMPHONIE.

Influence of anode thickness on the power output of solid oxide fuel cells with (La,Sr)(Co,Fe)-type cathode

NASA Astrophysics Data System (ADS)

Menzler, Norbert H.; Haanappel, Vincent A. C.

The influence of the thickness of the anode (functional layer) on the power output of anode-supported solid oxide fuel cells with a lanthanum-strontium-cobalt-ferrite cathode was investigated. The anode was applied by vacuum slip casting and the thickness varied between 1 and 22 μm. All other material and microstructural parameters were kept constant. Single cells with dimensions of 50 mm × 50 mm and with an active cathode area of 40 mm × 40 mm were manufactured and tested in an alumina housing with air as oxidant and hydrogen with 3% water vapour as the fuel gas. Results have shown that SOFCs with anodes between 1 and 13 μm have slightly better performance than those with thicker anodes (∼1.7 A cm -2 versus 1.5 A cm -2 at 800 °C and 0.7 V). The current densities were discussed with respect to cell area specific resistance, helium leak rate of the half-cell, and microstructure.

40 CFR 280.52 - Release investigation and confirmation steps.

Code of Federal Regulations, 2010 CFR

2010-07-01

... testing in § 280.43(c) and § 280.44(b)) that determine whether a leak exists in that portion of the tank... F if the test results for the system, tank, or delivery piping indicate that a leak exists. (2... indicate that a leak exists and if environmental contamination is not the basis for suspecting a release...

40 CFR 63.984 - Fuel gas systems and processes to which storage vessel, transfer rack, or equipment leak...

Code of Federal Regulations, 2010 CFR

2010-07-01

... function in that process; (ii) Transformed by chemical reaction into materials that are not regulated... evaluation (or engineering assessment) that demonstrates the extent to which one or more of the conditions...

29 CFR Appendix to Subpart E of... - Exit Routes, Emergency Action Plans, and Fire Prevention Plans

Code of Federal Regulations, 2010 CFR

2010-07-01

... necessary. Essential plant operations may include the monitoring of plant power supplies, water supplies... detect fuel leaks. An example is a temperature limit switch often found on deep-fat food fryers found in...

40 CFR 63.984 - Fuel gas systems and processes to which storage vessel, transfer rack, or equipment leak...

Code of Federal Regulations, 2011 CFR

2011-07-01

... function in that process; (ii) Transformed by chemical reaction into materials that are not regulated... evaluation (or engineering assessment) that demonstrates the extent to which one or more of the conditions...

Risk Factors for Gastrointestinal Leak after Bariatric Surgery: MBASQIP Analysis.

PubMed

Alizadeh, Reza Fazl; Li, Shiri; Inaba, Colette; Penalosa, Patrick; Hinojosa, Marcelo W; Smith, Brian R; Stamos, Michael J; Nguyen, Ninh T

2018-03-30

Gastrointestinal leak remains one of the most dreaded complications in bariatric surgery. We aimed to evaluate risk factors and the impact of common perioperative interventions on the development of leak in patients who underwent laparoscopic bariatric surgery. Using the 2015 database of accredited centers, data were analyzed for patients who underwent laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass (LRYGB). Emergent, revisional, and converted cases were excluded. Multivariate logistic regression was used to analyze risk factors for leak, including provocative testing of anastomosis, surgical drain placement, and use of postoperative swallow study. Data from 133,478 patients who underwent laparoscopic sleeve gastrectomy (n = 92,495 [69.3%]) and LRYGB (n = 40,983 [30.7%]) were analyzed. Overall leak rate was 0.7% (938 of 133,478). Factors associated with increased risk for leak were oxygen dependency (adjusted odds ratio [AOR] 1.97), hypoalbuminemia (AOR 1.66), sleep apnea (AOR 1.52), hypertension (AOR 1.36), and diabetes (AOR 1.18). Compared with LRYGB, laparoscopic sleeve gastrectomy was associated with a lower risk of leak (AOR 0.52; 95% CI 0.44 to 0.61; p < 0.01). Intraoperative provocative test was performed in 81.9% of cases and the leak rate was higher in patients with vs without a provocative test (0.8% vs 0.4%, respectively; p < 0.01). A surgical drain was placed in 24.5% of cases and the leak rate was higher in patients with vs without a surgical drain placed (1.6% vs 0.4%, respectively; p < 0.01). A swallow study was performed in 41% of cases and the leak rate was similar between patients with vs without swallow study (0.7% vs 0.7%; p = 0.50). The overall rate of gastrointestinal leak in bariatric surgery is low. Certain preoperative factors, procedural type (LRYGB), and interventions (intraoperative provocative test and surgical drain placement) were associated with a higher risk for leaks. Copyright © 2018 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Thermal stratification in LH2 tank of cryogenic propulsion stage tested in ISRO facility

NASA Astrophysics Data System (ADS)

Xavier, M.; Raj, R. Edwin; Narayanan, V.

2017-02-01

Liquid oxygen and hydrogen are used as oxidizer and fuel respectively in cryogenic propulsion system. These liquids are stored in foam insulated tanks of cryogenic propulsion system and are pressurized using warm pressurant gas supplied for tank pressure maintenance during cryogenic engine operation. Heat leak to cryogenic propellant tank causes buoyancy driven liquid stratification resulting in formation of warm liquid stratum at liquid free surface. This warm stratum is further heated by the admission of warm pressurant gas for tank pressurization during engine operation. Since stratified layer temperature has direct bearing on the cavitation free operation of turbo pumps integrated in cryogenic engine, it is necessary to model the thermal stratification for predicting stratified layer temperature and mass of stratified liquid in tank at the end of engine operation. These inputs are required for estimating the minimum pressure to be maintained by tank pressurization system. This paper describes configuration of cryogenic stage for ground qualification test, stage hot test sequence, a thermal model and its results for a foam insulated LH2 tank subjected to heat leak and pressurization with hydrogen gas at 200 K during liquid outflow at 38 lps for engine operation. The above model considers buoyancy flow in free convection boundary layer caused by heat flux from tank wall and energy transfer from warm pressurant gas etc. to predict temperature of liquid stratum and mass of stratified liquid in tank at the end of engine operation in stage qualification tests carried out in ISRO facility.

NASA Alternative Aviation Fuel Research

NASA Astrophysics Data System (ADS)

Anderson, B. E.; Beyersdorf, A. J.; Thornhill, K. L., II; Moore, R.; Shook, M.; Winstead, E.; Ziemba, L. D.; Crumeyrolle, S.

2015-12-01

We present an overview of research conducted by NASA Aeronautics Research Mission Directorate to evaluate the performance and emissions of "drop-in" alternative jet fuels, highlighting experiment design and results from the Alternative Aviation Fuel Experiments (AAFEX-I & -II) and Alternative Fuel-Effects on Contrails and Cruise Emissions flight series (ACCESS-I & II). These projects included almost 100 hours of sampling exhaust emissions from the NASA DC-8 aircraft in both ground and airborne operation and at idle to takeoff thrust settings. Tested fuels included Fischer-Tropsch (FT) synthetic kerosenes manufactured from coal and natural-gas feedstocks; Hydro-treated Esters and Fatty-Acids (HEFA) fuels made from beef-tallow and camelina-plant oil; and 50:50 blends of these alternative fuels with Jet A. Experiments were also conducted with FT and Jet A fuels doped with tetrahydrothiophene to examine the effects of fuel sulfur on volatile aerosol and contrail formation and microphysical properties. Results indicate that although the absence of aromatic compounds in the alternative fuels caused DC-8 fuel-system leaks, the fuels did not compromise engine performance or combustion efficiency. And whereas the alternative fuels produced only slightly different gas-phase emissions, dramatic reductions in non-volatile particulate matter (nvPM) emissions were observed when burning the pure alternative fuels, particularly at low thrust settings where particle number and mass emissions were an order of magnitude lower than measured from standard jet fuel combustion; 50:50 blends of Jet A and alternative fuels typically reduced nvPM emissions by ~50% across all thrust settings. Alternative fuels with the highest hydrogen content produced the greatest nvPM reductions. For Jet A and fuel blends, nvPM emissions were positively correlated with fuel aromatic and naphthalene content. Fuel sulfur content regulated nucleation mode aerosol number and mass concentrations within aging exhaust plumes, but did not clearly impact contrail formation or microphysics.

Influence of wetting effect at the outer surface of the pipe on increase in leak rate - experimental results and discussion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isozaki, Toshikuni; Shibata, Katsuyuki

1997-04-01

Experimental and computed results applicable to Leak Before Break analysis are presented. The specific area of investigation is the effect of the temperature distribution changes due to wetting of the test pipe near the crack on the increase in the crack opening area and leak rate. Two 12-inch straight pipes subjected to both internal pressure and thermal load, but not to bending load, are modelled. The leak rate was found to be very susceptible to the metal temperature of the piping. In leak rate tests, therefore, it is recommended that temperature distribution be measured precisely for a wide area.

Transepithelial leak in Barrett's esophagus patients: The role of proton pump inhibitors

PubMed Central

Farrell, Christopher; Morgan, Melissa; Tully, Owen; Wolov, Kevin; Kearney, Keith; Ngo, Benjamin; Mercogliano, Giancarlo; Thornton, James J; Valenzano, Mary Carmen; Mullin, James M

2012-01-01

AIM: To determine if the observed paracellular sucrose leak in Barrett’s esophagus patients is due to their proton pump inhibitor (PPI) use. METHODS: The in vivo sucrose permeability test was administered to healthy controls, to Barrett’s patients and to non-Barrett’s patients on continuous PPI therapy. Degree of leak was tested for correlation with presence of Barrett’s, use of PPIs, and length of Barrett’s segment and duration of PPI use. RESULTS: Barrett’s patients manifested a near 3-fold greater, upper gastrointestinal sucrose leak than healthy controls. A decrease of sucrose leak was observed in Barrett’s patients who ceased PPI use for 7 d. Although initial introduction of PPI use (in a PPI-naïve population) results in dramatic increase in sucrose leak, long-term, continuous PPI use manifested a slow spontaneous decline in leak. The sucrose leak observed in Barrett’s patients showed no correlation to the amount of Barrett’s tissue present in the esophagus. CONCLUSION: Although future research is needed to determine the degree of paracellular leak in actual Barrett’s mucosa, the relatively high degree of leak observed with in vivo sucrose permeability measurement of Barrett’s patients reflects their PPI use and not their Barrett’s tissue per se. PMID:22719187

Measuring Small Leak Holes

NASA Technical Reports Server (NTRS)

Koch, D. E.; Stephenson, J. G.

1983-01-01

Hole sizes deduced from pressure measurements. Measuring apparatus consists of pitot tube attached to water-filled manometer. Compartment tested is pressurized with air. Pitot probe placed at known distance from leak. Dynamic pressure of jet measured at that point and static pressure measured in compartment. Useful in situations in which small leaks are tolerable but large leaks are not.

Reduce Air Infiltration in Furnaces (English/Chinese) (Fact Sheet) (in Chinese; English)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Chinese translation of the Reduce Air Infiltration in Furnaces fact sheet. Provides suggestions on how to improve furnace energy efficiency. Fuel-fired furnaces discharge combustion products through a stack or a chimney. Hot furnace gases are less dense and more buoyant than ambient air, so they rise, creating a differential pressure between the top and the bottom of the furnace. This differential, known as thermal head, is the source of a natural draft or negative pressure in furnaces and boilers. A well-designed furnace (or boiler) is built to avoid air leakage into the furnace or leakage of flue gases from themore » furnace to the ambient. However, with time, most furnaces develop cracks or openings around doors, joints, and hearth seals. These openings (leaks) usually appear small compared with the overall dimensions of the furnace, so they are often ignored. The negative pressure created by the natural draft (or use of an induced-draft fan) in a furnace draws cold air through the openings (leaks) and into the furnace. The cold air becomes heated to the furnace exhaust gas temperature and then exits through the flue system, wasting valuable fuel. It might also cause excessive oxidation of metals or other materials in the furnaces. The heat loss due to cold air leakage resulting from the natural draft can be estimated if you know four major parameters: (1) The furnace or flue gas temperature; (2) The vertical distance H between the opening (leak) and the point where the exhaust gases leave the furnace and its flue system (if the leak is along a vertical surface, H will be an average value); (3) The area of the leak, in square inches; and (4) The amount of operating time the furnace spends at negative pressure. Secondary parameters that affect the amount of air leakage include these: (1) The furnace firing rate; (2) The flue gas velocity through the stack or the stack cross-section area; (3) The burner operating conditions (e.g., excess air, combustion air temperature, and so on). For furnaces or boilers using an induced-draft (ID) fan, the furnace negative pressure depends on the fan performance and frictional losses between the fan inlet and the point of air leakage. In most cases, it would be necessary to measure or estimate negative pressure at the opening. The amount of air leakage, the heat lost in flue gases, and their effects on increased furnace or boiler fuel consumption can be calculated by using the equations and graphs given in Industrial Furnaces (see W. Trinks et al., below). Note that the actual heat input required to compensate for the heat loss in flue gases due to air leakage would be greater than the heat contained in the air leakage because of the effect of available heat in the furnace. For a high-temperature furnace that is not maintained properly, the fuel consumption increase due to air leakage can be as high as 10% of the fuel input.« less

KSC-2010-5852

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Space shuttle Discovery's external fuel tank is outfitted with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

KSC-2010-5848

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Space shuttle Discovery's external fuel tank is outfitted with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

KSC-2010-5851

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Technicians outfit space shuttle Discovery's external fuel tank with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

KSC-2010-5849

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Technicians outfit space shuttle Discovery's external fuel tank with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

KSC-2010-5855

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Technicians outfit space shuttle Discovery's external fuel tank with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

KSC-2010-5854

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Technicians outfit space shuttle Discovery's external fuel tank with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

KSC-2010-5853

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Space shuttle Discovery's external fuel tank is outfitted with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

KSC-2010-5850

NASA Image and Video Library

2010-12-14

CAPE CANAVERAL, Fla. -- Technicians outfit space shuttle Discovery's external fuel tank with approximately 89 strain gauges, thermocouples and wiring in preparation for a tanking test no earlier than Dec. 17 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the external tank's intertank area, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jim Grossmann

40 CFR 63.984 - Fuel gas systems and processes to which storage vessel, transfer rack, or equipment leak...

Code of Federal Regulations, 2014 CFR

2014-07-01

... times when regulated material emissions are routed to it. (2) The owner or operator of a transfer rack... function in that process; (ii) Transformed by chemical reaction into materials that are not regulated...

40 CFR 63.984 - Fuel gas systems and processes to which storage vessel, transfer rack, or equipment leak...

Code of Federal Regulations, 2012 CFR

2012-07-01

... times when regulated material emissions are routed to it. (2) The owner or operator of a transfer rack... function in that process; (ii) Transformed by chemical reaction into materials that are not regulated...

Clean Air Program : cylinder issues associated with alternative fuels

DOT National Transportation Integrated Search

1999-01-01

A number of incidents of compressed natural gas (CNG) cylinder leaks have occurred while transit buses were either in service or at a bus maintenance facility. This study was initiated to determine the degree to which cylinder problems still exist in...

Analytical and Experimental Studies of Leak Location and Environment Characterization for the International Space Station

NASA Technical Reports Server (NTRS)

Woronowicz, Michael; Abel, Joshua; Autrey, David; Blackmon, Rebecca; Bond, Tim; Brown, Martin; Buffington, Jesse; Cheng, Edward; DeLatte, Danielle; Garcia, Kelvin;

Analytical and Experimental Studies of Leak Location and Environment Characterization for the International Space Station

NASA Technical Reports Server (NTRS)

Woronowicz, Michael S.; Abel, Joshua C.; Autrey, David; Blackmon, Rebecca; Bond, Tim; Brown, Martin; Buffington, Jesse; Cheng, Edward; DeLatte, Danielle; Garcia, Kelvin;

High-voltage leak detection of a parenteral proteinaceous solution product packaged in form-fill-seal plastic laminate bags. Part 1. Method development and validation.

PubMed

Damgaard, Rasmus; Rasmussen, Mats; Buus, Peter; Mulhall, Brian; Guazzo, Dana Morton

2013-01-01

In Part 1 of this three-part research series, a leak test performed using high-voltage leak detection (HVLD) technology, also referred to as an electrical conductivity and capacitance leak test, was developed and validated for container-closure integrity verification of a small-volume laminate plastic bag containing an aqueous solution for injection. The sterile parenteral product is the rapid-acting insulin analogue, insulin aspart (NovoRapid®/NovoLog®, by Novo Nordisk A/S, Bagsværd, Denmark). The aseptically filled and sealed package is designed to preserve product sterility through expiry. Method development and validation work incorporated positive control packages with a single hole laser-drilled through the laminate film of each bag. A unique HVLD method characterized by specific high-voltage and potentiometer set points was established for testing bags positioned in each of three possible orientations as they are conveyed through the instrument's test zone in each of two possible directions-resulting in a total of six different test method options. Validation study results successfully demonstrated the ability of all six methods to accurately and reliably detect those packages with laser-drilled holes from 2.5-11.2 μm in nominal diameter. Part 2 of this series will further explore HVLD test results as a function of package seal and product storage variables. The final Part 3 will report the impact of HVLD exposure on product physico-chemical stability. In this Part 1 of a three-part research series, a leak test method based on electrical conductivity and capacitance, called high voltage leak detection (HVLD), was used to find leaks in small plastic bags filled with an insulin pharmaceutical solution for human injection by Novo Nordisk A/S (Bagsværd, Denmark). To perform the test, the package is electrically grounded while being conveyed past an electrode linked to a high-voltage, low-amperage transformer. The instrument measures the current that passes from the transformer to the electrode, through the packaged product and along the package walls, to the ground. Plastic packages without defect are relatively nonconductive and yield a low voltage reading; a leaking package with electrically conductive solution located in or near the leak triggers a spike in voltage reading. Test methods were optimized and validated, enabling the detection of leaking packages with holes as small as 2.5 μm in diameter. Part 2 of this series will further explore HVLD test results as a function of package seal and product storage variables. The final Part 3 will report the impact of HVLD exposure on product stability.

Apparatus for Leak Testing Pressurized Hoses

NASA Technical Reports Server (NTRS)

Underwood, Steve D. (Inventor); Garrison, Steve G. (Inventor); Gant, Bobby D. (Inventor); Palmer, John R. (Inventor)

2015-01-01

A hose-attaching apparatus for leak-testing a pressurized hose may include a hose-attaching member. A bore may extend through the hose-attaching member. An internal annular cavity may extend coaxially around the bore. At least one of a detector probe hole and a detector probe may be connected to the internal annular cavity. At least a portion of the bore may have a diameter which is at least one of substantially equal to and less than a diameter of a hose to be leak-tested.

Integrity of Disposable Nitrile Exam Gloves Exposed to Simulated Movement

PubMed Central

Phalen, Robert N.; Wong, Weng Kee

2011-01-01

Every year, millions of health care, first responder, and industry workers are exposed to chemical and biological hazards. Disposable nitrile gloves are a common choice as both a chemical and physical barrier to these hazards, especially as an alternative to natural latex gloves. However, glove selection is complicated by the availability of several types or formulations of nitrile gloves, such as low-modulus, medical-grade, low-filler, and cleanroom products. This study evaluated the influence of simulated movement on the physical integrity (i.e., holes) of different nitrile exam glove brands and types. Thirty glove products were evaluated out-of-box and after exposure to simulated whole-glove movement for 2 hr. In lieu of the traditional 1-L water-leak test, a modified water-leak test, standardized to detect a 0.15 ± 0.05 mm hole in different regions of the glove, was developed. A specialized air inflation method simulated bidirectional stretching and whole-glove movement. A worst-case scenario with maximum stretching was evaluated. On average, movement did not have a significant effect on glove integrity (chi-square; p=0.068). The average effect was less than 1% between no movement (1.5%) and movement (2.1%) exposures. However, there was significant variability in glove integrity between different glove types (p ≤ 0.05). Cleanroom gloves, on average, had the highest percentage of leaks, and 50% failed the water-leak test. Low-modulus and medical-grade gloves had the lowest percentages of leaks, and no products failed the water-leak test. Variability in polymer formulation was suspected to account for the observed discrepancies, as well as the inability of the traditional 1-L water-leak test to detect holes in finger/thumb regions. Unexpectedly, greater than 80% of the glove defects were observed in the finger and thumb regions. It is recommended that existing water-leak tests be re-evaluated and standardized to account for product variability. PMID:21476169

Test/QA Plan for Verification of Leak Detection and Repair Technologies

EPA Science Inventory

The purpose of the leak detection and repair (LDAR) test and quality assurance plan is to specify procedures for a verification test applicable to commercial LDAR technologies. The purpose of the verification test is to evaluate the performance of participating technologies in b...

A Fully Redundant On-Line Mass Spectrometer System Used to Monitor Cryogenic Fuel Leaks on the Space Shuttle

NASA Technical Reports Server (NTRS)

Griffin, Timothy P.; Naylor, Guy R.; Haskell, William D.; Breznik, Greg S.; Mizell, Carolyn A.; Helms, William R.; Voska, N. (Technical Monitor)

2002-01-01

An on-line gas monitoring system was developed to replace the older systems used to monitor for cryogenic leaks on the Space Shuttles before launch. The system uses a mass spectrometer to monitor multiple locations in the process, which allows the system to monitor all gas constituents of interest in a nearly simultaneous manner. The system is fully redundant and meets all requirements for ground support equipment (GSE). This includes ruggedness to withstand launch on the Mobile Launcher Platform (MLP), ease of operation, and minimal operator intervention. The system can be fully automated so that an operator is notified when an unusual situation or fault is detected. User inputs are through personal computer using mouse and keyboard commands. The graphical user for detecting cryogenic leaks, many other gas constituents could be monitored using the Hazardous Gas Detection System (HGDS) 2000.

Of Detection Limits and Effective Mitigation: The Use of Infrared Cameras for Methane Leak Detection

NASA Astrophysics Data System (ADS)

Ravikumar, A. P.; Wang, J.; McGuire, M.; Bell, C.; Brandt, A. R.

2017-12-01

Mitigating methane emissions, a short-lived and potent greenhouse gas, is critical to limiting global temperature rise to two degree Celsius as outlined in the Paris Agreement. A major source of anthropogenic methane emissions in the United States is the oil and gas sector. To this effect, state and federal governments have recommended the use of optical gas imaging systems in periodic leak detection and repair (LDAR) surveys to detect for fugitive emissions or leaks. The most commonly used optical gas imaging systems (OGI) are infrared cameras. In this work, we systematically evaluate the limits of infrared (IR) camera based OGI system for use in methane leak detection programs. We analyze the effect of various parameters that influence the minimum detectable leak rates of infrared cameras. Blind leak detection tests were carried out at the Department of Energy's MONITOR natural gas test-facility in Fort Collins, CO. Leak sources included natural gas wellheads, separators, and tanks. With an EPA mandated 60 g/hr leak detection threshold for IR cameras, we test leak rates ranging from 4 g/hr to over 350 g/hr at imaging distances between 5 ft and 70 ft from the leak source. We perform these experiments over the course of a week, encompassing a wide range of wind and weather conditions. Using repeated measurements at a given leak rate and imaging distance, we generate detection probability curves as a function of leak-size for various imaging distances, and measurement conditions. In addition, we estimate the median detection threshold - leak-size at which the probability of detection is 50% - under various scenarios to reduce uncertainty in mitigation effectiveness. Preliminary analysis shows that the median detection threshold varies from 3 g/hr at an imaging distance of 5 ft to over 150 g/hr at 50 ft (ambient temperature: 80 F, winds < 4 m/s). Results from this study can be directly used to improve OGI based LDAR protocols and reduce uncertainty in estimated mitigation effectiveness. Furthermore, detection limits determined in this study can be used as standards to compare new detection technologies.

78 FR 49379 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-14

... require revising the maintenance program to incorporate changes to the airworthiness limitations section... fuel leak near an ignition source (e.g., hot brakes or engine exhaust nozzle), consequently leading to... we receive, without change, to http://www.regulations.gov , including any personal information you...

10 CFR 55.59 - Requalification.

Code of Federal Regulations, 2012 CFR

2012-01-01

... system. (U) Fuel cladding failure or high activity in reactor coolant or offgas. (V) Turbine or generator... heatup rate is established. (B) Plant shutdown. (C) Manual control of steam generators or feedwater or... generator leaks (2)Inside and outside primary containment (3)Large and small, including lead-rate...

10 CFR 55.59 - Requalification.

Code of Federal Regulations, 2011 CFR

2011-01-01

... system. (U) Fuel cladding failure or high activity in reactor coolant or offgas. (V) Turbine or generator... heatup rate is established. (B) Plant shutdown. (C) Manual control of steam generators or feedwater or... generator leaks (2)Inside and outside primary containment (3)Large and small, including lead-rate...

10 CFR 55.59 - Requalification.

Code of Federal Regulations, 2013 CFR

2013-01-01

... system. (U) Fuel cladding failure or high activity in reactor coolant or offgas. (V) Turbine or generator... heatup rate is established. (B) Plant shutdown. (C) Manual control of steam generators or feedwater or... generator leaks (2)Inside and outside primary containment (3)Large and small, including lead-rate...

A Fully Redundant On-Line Mass Spectrometer System Used to Monitor Cryogenic Fuel Leaks on the Space Shuttle

NASA Technical Reports Server (NTRS)

Griffin, Timothy P.; Naylor, Guy R.; Haskell, William D.; Breznik, Greg S.; Mizell, Carolyn A.; Helms, William R.; Steinrock, T. (Technical Monitor)

2001-01-01

An on-line gas monitoring system was developed to replace the older systems used to monitor for cryogenic leaks on the Space Shuttles before launch. The system uses a mass spectrometer to monitor multiple locations in the process, which allows the system to monitor all gas constituents of interest in a nearly simultaneous manner. The system is fully redundant and meets all requirements for ground support equipment (GSE). This includes ruggedness to withstand launch on the Mobile Launcher Platform (MLP), ease of operation, and minimal operator intervention. The system can be fully automated so that an operator is notified when an unusual situation or fault is detected. User inputs are through personal computer using mouse and keyboard commands. The graphical user interface is very intuitive and easy to operate. The system has successfully supported four launches to date. It is currently being permanently installed as the primary system monitoring the Space Shuttles during ground processing and launch operations. Time and cost savings will be substantial over the current systems when it is fully implemented in the field. Tests were performed to demonstrate the performance of the system. Low limits-of-detection coupled with small drift make the system a major enhancement over the current systems. Though this system is currently optimized for detecting cryogenic leaks, many other gas constituents could be monitored using the Hazardous Gas Detection System (HGDS) 2000.

Verification of International Space Station Component Leak Rates by Helium Accumulation Method

NASA Technical Reports Server (NTRS)

Underwood, Steve D.; Smith, Sherry L.

2003-01-01

Discovery of leakage on several International Space Station U.S. Laboratory Module ammonia system quick disconnects (QDs) led to the need for a process to quantify total leakage without removing the QDs from the system. An innovative solution was proposed allowing quantitative leak rate measurement at ambient external pressure without QD removal. The method utilizes a helium mass spectrometer configured in the detector probe mode to determine helium leak rates inside a containment hood installed on the test component. The method was validated through extensive developmental testing. Test results showed the method was viable, accurate and repeatable for a wide range of leak rates. The accumulation method has been accepted by NASA and is currently being used by Boeing Huntsville, Boeing Kennedy Space Center and Boeing Johnson Space Center to test welds and valves and will be used by Alenia to test the Cupola. The method has been used in place of more expensive vacuum chamber testing which requires removing the test component from the system.

Locating air leaks in manned spacecraft using structure-borne noise.

PubMed

Holland, Stephen D; Chimenti, D E; Roberts, Ron; Strei, Michael

2007-06-01

All manned spacecraft are vulnerable to leaks generated by micrometeorite or debris impacts. Methods for locating such leaks using leak-generated, structure-borne ultrasonic noise are discussed and demonstrated. Cross-correlations of ultrasonic noise waveforms from a leak into vacuum are used to find the location of the leak. Four methods for sensing and processing leak noise have been developed and tested and each of these can be used to reveal the leak location. The methods, based on phased-array, distributed sensor, and dual sensor approaches, utilize the propagation patterns of guided ultrasonic Lamb waves in the spacecraft skin structure to find the source or direction of the leak noise. It is shown that each method can be used to successfully locate the leak to within a few millimeters on a 0.6-m2 aluminum plate. The relative merits of the four methods are discussed.

Field Observations of Methane Emissions from Unconventional and Conventional Fossil Fuel Exploration

NASA Astrophysics Data System (ADS)

Dubey, M.; Lindenmaier, R.; Arata, C.; Costigan, K. R.; Frankenberg, C.; Kort, E. A.; Rahn, T. A.; Henderson, B. G.; Love, S. P.; Aubrey, A. D.

2013-12-01

Energy from methane (CH4) has lower carbon dioxide and air pollutant emissions per unit energy produced than coal or oil making it a desirable fossil fuel. Hydraulic fracturing is allowing United States to harvest the nation's abundant domestic shale gas reservoirs to achieve energy independence. However, CH4 is a gas that is hard to contain during mining, processing, transport and end-use. Therefore fugitive CH4 leaks occur that are reported in bottom up inventories by the EPA. Recent targeted field observations at selected plays have provided top down CH4 leak estimates that are larger than the reported EPA inventories. Furthermore, no long-term regional baselines are available to delineate leaks from unconventional mining operations from historical conventional mining. We will report and compare observations of fugitive CH4 leaks from conventional and unconventional mining to understand changes from technology shifts. We will report in situ and regional column measurements of CH4, its isotopologue 13CH4 and ethane (C2H6) at our Four Corners site near Farmington, NM. The region has substantial coal bed methane, conventional oil and gas production, processing and distribution with minimal hydraulic fracturing activity. We observe large enhancements in in situ and regional column CH4 with distinct time dependence. Our in situ 13CH4 observations and remote C2H6/CH4 provide strong evidence of thermogenic sources. Comparisons of WRF-simulations with emissions inventory (Edgar) with our observations show that the fugitive CH4 leaks from conventional mining are 3 times greater than reported. We also compare in situ mobile surveys of fugitive CH4 and 13CH4 leak signals in basins with conventional (San Juan) mining and unconventional (Permian and Powder River) mining. A large number of active and closed wells were sampled in these regions. Furthermore, play scale surveys on public roads allowed us to gain a regional perspective. The composition of atmospheric 13CH4 observed in the Powder River basin was lighter than the Permian and San Juan basins indicating a higher microbial generated fraction. More extensive and larger CH4 enhancements were measured in the Permian basin that could be a result of the large expansion of unconventional oil and gas production in this region. However, there are variations amongst wells and plays suggesting that operator practices and reservoir formation play a role in determining the fugitive leaks.

Soybean-derived biofuels and home heating fuels.

PubMed

Mushrush, George W; Wynne, James H; Willauer, Heather D; Lloyd, Christopher L

2006-01-01

It is environmentally enticing to consider replacing or blending petroleum derived heating fuels with biofuels for many reasons. Major considerations include the soaring worldwide price of petroleum products, especially home heating oil, the toxicity of the petroleum-derived fuels and the environmental damage that leaking petroleum tanks afford. For these reasons, it has been suggested that domestic renewable energy sources be considered as replacements, or at the least, as blending stocks for home heating fuels. If recycled soy restaurant cooking oils could be employed for this purpose, this would represent an environmental advantage. Renewable plant sources of energy tend to be less toxic than their petroleum counterparts. This is an important consideration when tank leakage occurs. Home fuel oil storage tanks practically always contain some bottom water. This water environment has a pH value that factors into heating fuel stability. Therefore, the question is: would the biofuel help or exacerbate fuel stability and furnace maintenance issues?

High-voltage leak detection of a parenteral proteinaceous solution product packaged in form-fill-seal plastic laminate bags. Part 2. Method performance as a function of heat seal defects, product-package refrigeration, and package plastic laminate lot.

PubMed

Rasmussen, Mats; Damgaard, Rasmus; Buus, Peter; Mulhall, Brian; Guazzo, Dana Morton

2013-01-01

Part 1 of this three-part research series detailed the development and validation of a high-voltage leak detection test (HVLD, also known as an electrical conductivity and capacitance test) for verifying the container-closure integrity of a small-volume laminate plastic bag containing an aqueous solution formulation of the rapid-acting insulin analogue, insulin aspart (NovoRapid®/NovoLog®) by Novo Nordisk A/S, Bagsværd, Denmark. Leak detection capability was verified using positive controls each with a single laser-drilled hole in the bag film face. In this Part 2, HVLD leak detection capability was further explored in four separate studies. Study 1 investigated the ability of HVLD to detect weaknesses and/or gaps in the bag heat seal. Study 2 checked the HVLD detection of bag holes in packages stored 4 days at ambient conditions followed by 17 days at refrigeration. Study 3 examined HVLD test results for packages tested when cold. Study 4 compared HVLD test results as a function of bag plastic film lots. The final Part 3 of this series will report the impact of HVLD exposure on product visual appearance and chemical stability. In Part 1 of this three-part series, a leak test method based on electrical conductivity and capacitance, also called high-voltage leak detection (HVLD), was used to find leaks in small plastic bags filled with a solution for injection of the rapid-acting insulin analogue, insulin aspart (NovoRapid®/NovoLog®) by Novo Nordisk A/S, Bagsværd, Denmark. In this Part 2, HVLD leak detection capability was further explored in four separate studies. Study 1 investigated the ability of HVLD to detect bag heat seal leaks. Study 2 checked HVLD's ability to detect bag holes after a total of 21 days at ambient plus refrigerated temperatures. Study 3 looked to see if HVLD results changed for packages tested when still cold. Study 4 compared HVLD results for multiple bag plastic film lots. The final Part 3 of this series will report any evidence of drug component degradation caused by HVLD exposure.

Hydrogen Fuel Capability Added to Combustor Flametube Rig

NASA Technical Reports Server (NTRS)

Frankenfield, Bruce J.

2003-01-01

Facility capabilities have been expanded at Test Cell 23, Research Combustor Lab (RCL23) at the NASA Glenn Research Center, with a new gaseous hydrogen fuel system. The purpose of this facility is to test a variety of fuel nozzle and flameholder hardware configurations for use in aircraft combustors. Previously, this facility only had jet fuel available to perform these various combustor flametube tests. The new hydrogen fuel system will support the testing and development of aircraft combustors with zero carbon dioxide (CO2) emissions. Research information generated from this test rig includes combustor emissions and performance data via gas sampling probes and emissions measuring equipment. The new gaseous hydrogen system is being supplied from a 70 000-standard-ft3 tube trailer at flow rates up to 0.05 lb/s (maximum). The hydrogen supply pressure is regulated, and the flow is controlled with a -in. remotely operated globe valve. Both a calibrated subsonic venturi and a coriolis mass flowmeter are used to measure flow. Safety concerns required the placement of all hydrogen connections within purge boxes, each of which contains a small nitrogen flow that is vented past a hydrogen detector. If any hydrogen leaks occur, the hydrogen detectors alert the operators and automatically safe the facility. Facility upgrades and modifications were also performed on other fluids systems, including the nitrogen gas, cooling water, and air systems. RCL23 can provide nonvitiated heated air to the research combustor, up to 350 psig at 1200 F and 3.0 lb/s. Significant modernization of the facility control systems and the data acquisition systems was completed. A flexible control architecture was installed that allows quick changes of research configurations. The labor-intensive hardware interface has been removed and changed to a software-based system. In addition, the operation of this facility has been greatly enhanced with new software programming and graphic operator interface stations. Glenn s RCL23 facility systems were successfully checked out in the spring of 2002, and hydrogen combustor research testing began in the summer of 2002.

AAFES Gas Station at Creech Air Force Base Environmental Assessment

DTIC Science & Technology

2009-07-01

Creech AFB with modern fuel refilling services. The AAFES Gas Station would include a one pump two hose filling station, a concrete slab, a 12,000...at both end of each hose , a shear valve at the base of the pump, and an electronic sensor in the dispenser to detect fuel leakage. In order to add...designed and built with leak prevention safety equipment. Shut- off valves would be installed at both ends of each hose . A shear valve would be

Color-Changing Sensors for Detecting the Presence of Hypergolic Fuels

NASA Technical Reports Server (NTRS)

Roberson, Luke; Captain, Janine; Santiago-Maldonado, Edgardo; Starr, Stanley; DeVor, Robert

2013-01-01

Hypergolic fuel sensors were designed to incorporate novel chemochromic pigments into substrates for use in various methods of leak detection. There are several embodiments to this invention that would provide specific visual indication of hypergols used during and after transfer. The ability to incorporate these pigments into various polymer matrices provides a unique opportunity to manufacture nearly any type of sensor shape that is required. The vibrant color change from yellow to black instantaneously shows the worker the presence of hypergols in the area.

Analytical and experimental studies of leak location and environment characterization for the international space station

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woronowicz, Michael; Blackmon, Rebecca; Brown, Martin

2014-12-09

The International Space Station program is developing a robotically-operated leak locator tool to be used externally. The tool would consist of a Residual Gas Analyzer for partial pressure measurements and a full range pressure gauge for total pressure measurements. The primary application is to demonstrate the ability to detect NH{sub 3} coolant leaks in the ISS thermal control system. An analytical model of leak plume physics is presented that can account for effusive flow as well as plumes produced by sonic orifices and thruster operations. This model is used along with knowledge of typical RGA and full range gauge performancemore » to analyze the expected instrument sensitivity to ISS leaks of various sizes and relative locations (“directionality”). The paper also presents experimental results of leak simulation testing in a large thermal vacuum chamber at NASA Goddard Space Flight Center. This test characterized instrument sensitivity as a function of leak rates ranging from 1 lb{sub m/}/yr. to about 1 lb{sub m}/day. This data may represent the first measurements collected by an RGA or ion gauge system monitoring off-axis point sources as a function of location and orientation. Test results are compared to the analytical model and used to propose strategies for on-orbit leak location and environment characterization using the proposed instrument while taking into account local ISS conditions and the effects of ram/wake flows and structural shadowing within low Earth orbit.« less

KSC-2009-3839

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – The afternoon sun casts shadows on space shuttle Endeavour's external fuel tank as workers remove the seal from the Ground Umbilical Carrier Plate, or GUCP, on the tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2010-5639

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the ground umbilical carrier plate (GUCP) is removed from space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5645

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers examine the ground umbilical carrier plate (GUCP). A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5644

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers examine the ground umbilical carrier plate (GUCP). A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5638

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers remove the ground umbilical carrier plate (GUCP) from space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-3840

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, work continues on removing the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

Development of a nondestructive leak testing method utilizing the head space analyzer for ampoule products containing ethanol-based solutions.

PubMed

Sudo, Hirotaka; O'driscoll, Michael; Nishiwaki, Kenji; Kawamoto, Yuji; Gammell, Philip; Schramm, Gerhard; Wertli, Toni; Prinz, Heino; Mori, Atsuhide; Sako, Kazuhiro

2012-01-01

The application of a head space analyzer for oxygen concentration was examined to develop a novel ampoule leak test method. Studies using ampoules filled with ethanol-based solution and with nitrogen in the headspace demonstrated that the head space analysis (HSA) method showed sufficient sensitivity in detecting an ampoule crack. The proposed method is the use of HSA in conjunction with the pretreatment of an overpressurising process known as bombing to facilitate the oxygen flow through the crack in the ampoule. The method was examined in comparative studies with a conventional dye ingress method, and the results showed that the HSA method exhibits sensitivity superior to the dye method. The results indicate that the HSA method in combination with the bombing treatment provides potential application as a leak test for the detection of container defects not only for ampoule products with ethanol-based solutions, but also for testing lyophilized products in vials with nitrogen in the head space. The application of a head space analyzer for oxygen concentration was examined to develop a novel ampoule leak test method. The proposed method is the use of head space analysis (HSA) in conjunction with the pretreatment of an overpressurising process known as bombing to facilitate oxygen flow through the crack in the ampoule for use in routine production. The result of the comparative study with a conventional dye leak test method indicates that the HSA method in combination with the bombing treatment can be used as a leak test method, enabling detection of container defects.

Portable Microleak-Detection System

NASA Technical Reports Server (NTRS)

Rivers, H. Kevin; Sikora, Joseph G.; Sankaran, Sankara N.

2007-01-01

The figure schematically depicts a portable microleak-detection system that has been built especially for use in testing hydrogen tanks made of polymer-matrix composite materials. (As used here, microleak signifies a leak that is too small to be detectable by the simple soap-bubble technique.) The system can also be used to test for microleaks in tanks that are made of other materials and that contain gases other than hydrogen. Results of calibration tests have shown that measurement errors are less than 10 percent for leak rates ranging from 0.3 to 200 cm3/min. Like some other microleak-detection systems, this system includes a vacuum pump and associated plumbing for sampling the leaking gas, and a mass spectrometer for analyzing the molecular constituents of the gas. The system includes a flexible vacuum chamber that can be attached to the outer surface of a tank or other object of interest that is to be tested for leakage (hereafter denoted, simply, the test object). The gas used in a test can be the gas or vapor (e.g., hydrogen in the original application) to be contained by the test object. Alternatively, following common practice in leak testing, helium can be used as a test gas. In either case, the mass spectrometer can be used to verify that the gas measured by the system is the test gas rather than a different gas and, hence, that the leak is indeed from the test object.

Monitoring of noninvasive ventilation by built-in software of home bilevel ventilators: a bench study.

PubMed

Contal, Olivier; Vignaux, Laurence; Combescure, Christophe; Pepin, Jean-Louis; Jolliet, Philippe; Janssens, Jean-Paul

2012-02-01

Current bilevel positive-pressure ventilators for home noninvasive ventilation (NIV) provide physicians with software that records items important for patient monitoring, such as compliance, tidal volume (Vt), and leaks. However, to our knowledge, the validity of this information has not yet been independently assessed. Testing was done for seven home ventilators on a bench model adapted to simulate NIV and generate unintentional leaks (ie, other than of the mask exhalation valve). Five levels of leaks were simulated using a computer-driven solenoid valve (0-60 L/min) at different levels of inspiratory pressure (15 and 25 cm H(2)O) and at a fixed expiratory pressure (5 cm H(2)O), for a total of 10 conditions. Bench data were compared with results retrieved from ventilator software for leaks and Vt. For assessing leaks, three of the devices tested were highly reliable, with a small bias (0.3-0.9 L/min), narrow limits of agreement (LA), and high correlations (R(2), 0.993-0.997) when comparing ventilator software and bench results; conversely, for four ventilators, bias ranged from -6.0 L/min to -25.9 L/min, exceeding -10 L/min for two devices, with wide LA and lower correlations (R(2), 0.70-0.98). Bias for leaks increased markedly with the importance of leaks in three devices. Vt was underestimated by all devices, and bias (range, 66-236 mL) increased with higher insufflation pressures. Only two devices had a bias < 100 mL, with all testing conditions considered. Physicians monitoring patients who use home ventilation must be aware of differences in the estimation of leaks and Vt by ventilator software. Also, leaks are reported in different ways according to the device used.

Cleanup of a jet fuel spill

NASA Astrophysics Data System (ADS)

Fesko, Steve

1996-11-01

Eaton operates a corporate aircraft hanger facility in Battle Creek, Michigan. Tests showed that two underground storage tanks leaked. Investigation confirmed this release discharged several hundred gallons of Jet A kerosene into the soil and groundwater. The oil moved downward approximately 30 feet and spread laterally onto the water table. Test results showed kerosene in the adsorbed, free and dissolved states. Eaton researched and investigated three clean-up options. They included pump and treat, dig and haul and bioremediation. Jet fuel is composed of readily biodegradable hydrocarbon chains. This fact coupled with the depth to groundwater and geologic setting made bioremediation the low cost and most effective alternative. A recovery well was installed at the leading edge of the dissolved contamination. A pump moved water from this well into a nutrient addition system. Nutrients added included nitrogen, phosphorous and potassium. Additionally, air was sparged into the water. The water was discharged into an infiltration gallery installed when the underground storage tanks were removed. Water circulated between the pump and the infiltration basin in a closed loop fashion. This oxygenated, nutrient rich water actively and aggressively treated the soils between the bottom of the gallery and the top of the groundwater and the groundwater. The system began operating in August of 1993 and reduced jet fuel to below detection levels. In August of 1995 The State of Michigan issued a clean closure declaration to the site.

Operation of the WWR-S Reactor in Poland and in the Period 1961-1962; DOKLAD OB ISPOL'ZOVANII I EKSPLUATATSII REAKTORA TIPA VVR-C V POL'SHE ZA 1961-1962 GODA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aleksandrowicz, J.

1963-03-01

The experimental equipment used in the work at the horizontal reactor channels is listed. Diagrams of the utilization of the nominal reactor power and core loading are given, the reactivity fractions of the separate fuel assemblies are detonated, together with the diagram of reactivity versus burnup. Reactor channels and space used for sample irradiation and isotope production are described, and the total number of irradiations is given. Results of the measurements connected with the routine reactor operation are quoted, namely: analysis of water purity in the primary circuit, analysis of the work of the ion exchanger and mechanical filter, andmore » analysis of air activity in the special ventilation system. Data are given concerning radiation protection of personnel, including individual monitoring. Leak testing of the fuel elements is discussed. Damage of the reactor equipment and appearance of alarm signals are described. (auth)« less

40 CFR 1065.644 - Vacuum-decay leak rate.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Vacuum-decay leak rate. 1065.644 Section 1065.644 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.644 Vacuum-decay leak rate...

40 CFR 1065.644 - Vacuum-decay leak rate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Vacuum-decay leak rate. 1065.644 Section 1065.644 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.644 Vacuum-decay leak rate...

40 CFR 1065.644 - Vacuum-decay leak rate.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Vacuum-decay leak rate. 1065.644 Section 1065.644 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.644 Vacuum-decay leak rate...

40 CFR 1065.644 - Vacuum-decay leak rate.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Vacuum-decay leak rate. 1065.644 Section 1065.644 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.644 Vacuum-decay leak rate...

40 CFR 1065.644 - Vacuum-decay leak rate.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Vacuum-decay leak rate. 1065.644 Section 1065.644 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.644 Vacuum-decay leak rate...

KSC-2010-5844

NASA Image and Video Library

2010-12-10

CAPE CANAVERAL, Fla. -- Technicians prepare space shuttle Discovery's external fuel tank for a tanking test no earlier than Dec. 15 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the intertank, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Teams already have installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Frank Michaux

KSC-2010-5845

NASA Image and Video Library

2010-12-10

CAPE CANAVERAL, Fla. -- Technicians prepare space shuttle Discovery's external fuel tank for a tanking test no earlier than Dec. 15 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the intertank, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Teams already have installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Frank Michaux

KSC-2010-5834

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- Technicians prepare space shuttle Discovery's external fuel tank for a tanking test no earlier than Dec. 15 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the intertank, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Teams already have installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5847

NASA Image and Video Library

2010-12-10

CAPE CANAVERAL, Fla. -- Technicians prepare space shuttle Discovery's external fuel tank for a tanking test no earlier than Dec. 15 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the intertank, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Teams already have installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Frank Michaux

KSC-2010-5833

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- Technicians prepare space shuttle Discovery's external fuel tank for a tanking test no earlier than Dec. 15 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the intertank, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Teams already have installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5846

NASA Image and Video Library

2010-12-10

CAPE CANAVERAL, Fla. -- Technicians prepare space shuttle Discovery's external fuel tank for a tanking test no earlier than Dec. 15 on Launch Pad 39A at NASA's Kennedy Space Center in Florida. During the test, engineers will monitor what happens to 21-foot long, U-shaped aluminum brackets, called stringers, located at the intertank, as well as the newly replaced ground umbilical carrier plate (GUCP), during the loading of cryogenic propellants. Teams already have installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Frank Michaux

Long-term ageing and materials degradation of hybrid mica compressive seals for solid oxide fuel cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chou, Y. S.; Stevenson, Jeffry W.

2009-06-15

Hybrid phlogopite mica seals with silver interlayers were evaluated in long term isothermal ageing tests in a dual environment consisting of dilute hydrogen vs. air at 800 degrees C. High-temperature leak tests with helium showed very stable leakage of 0.01-0.02 sccm/cm for 28366 hrs under a low applied compressive stress of 82 kPa (12 psi). Post-mortem SEM and EDS analyses of the mica showed minimum degradation in terms of changes in microstructure and chemical composition, although there appeared to be some Ag migration and segregation at interstices between mica flakes. Fluorine was also found to be released from mica. Overall,more » the low, constant leakage through the hybrid mica/Ag seals clearly demonstrated a very promising candidate for SOFC sealing.« less

Repair of through thickness corrosion/leaking defects in corroded pipelines using Fiber Reinforced Polymer overwrap

NASA Astrophysics Data System (ADS)

Nitheesh Kumar, P.; Khan, Vishwas Chandra; Balaganesan, G.; Pradhan, A. K.; Sivakumar, M. S.

2018-04-01

The present study is concerned with the repair of through thickness corrosion or leaking defects in metallic pipelines using a commercially available metallic seal and glass/epoxy composite. Pipe specimens are made with three different types of most commonly occurring through thickness corrosion/leaking defects. The metallic seal is applied over the through thickness corrosion/leaking defect and it is reinforced with glass/epoxy composite overwrap. The main objective of the metallic seal is to arrest the leak at live pressure. After reinforcing the metallic seal with glass/epoxy composite overwrap, the repaired composite wrap is able to sustain high pressures. Burst test is performed for different configurations of metallic seal and optimum configuration of metallic seal is determined. The optimum configurations of metallic seal for three different types of through thickness corrosion/leaking defects are further reinforced with glass/epoxy composite wrap and experimental failure pressure is determined by performing the burst test. An analytical model as per ISO 24817 has been developed to validate experimental results.

40 CFR 59.660 - Exemption from the standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Control of Evaporative Emissions From New and In-Use Portable Fuel Containers Special Compliance... racing applications which are designed to create a leak proof seal with the target tank or are designed to connect with a receiver installed on the target tank. This exemption is generally intended for...

Anaerobic Biodegradation of Ethylene Dibromide and 1,2-Dichloroethane in the Presence of Fuel Hydrocarbons

EPA Science Inventory

Field evidence from underground storage tank sites where leaded gasoline leaked indicates the lead scavengers 1,2- dibromoethane (ethylene dibromide, or EDB) and 1,2- dichloroethane (1,2-DCA) may be present in groundwater at levels that pose unacceptable risk. These compounds are...

Quality Assurance Project Plan: Suitability of Leak Detection Technology for Use In Ethanol-Blended Fuel Service

EPA Science Inventory

Oversight of this investigation will be provided by the U.S. Environmental Protection Agency through the Environmental Technology Verification (ETV) Program. This project will be performed by Battelle, which manages the ETV Advanced Monitoring Systems (AMS) Center through a coop...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawn Lenz; Raymond T. Lines; Darryl Murdock

ITT Industries Space Systems Division (Space Systems) has developed an airborne natural gas leak detection system designed to detect, image, quantify, and precisely locate leaks from natural gas transmission pipelines. This system is called the Airborne Natural Gas Emission Lidar (ANGEL) system. The ANGEL system uses a highly sensitive differential absorption Lidar technology to remotely detect pipeline leaks. The ANGEL System is operated from a fixed wing aircraft and includes automatic scanning, pointing system, and pilot guidance systems. During a pipeline inspection, the ANGEL system aircraft flies at an elevation of 1000 feet above the ground at speeds of betweenmore » 100 and 150 mph. Under this contract with DOE/NETL, Space Systems was funded to integrate the ANGEL sensor into a test aircraft and conduct a series of flight tests over a variety of test targets including simulated natural gas pipeline leaks. Following early tests in upstate New York in the summer of 2004, the ANGEL system was deployed to Casper, Wyoming to participate in a set of DOE-sponsored field tests at the Rocky Mountain Oilfield Testing Center (RMOTC). At RMOTC the Space Systems team completed integration of the system and flew an operational system for the first time. The ANGEL system flew 2 missions/day for the duration for the 5-day test. Over the course of the week the ANGEL System detected leaks ranging from 100 to 5,000 scfh.« less

Applied breath analysis: an overview of the challenges and opportunities in developing and testing sensor technology for human health monitoring in aerospace and clinical applications

PubMed Central

Hunter, Gary W; Dweik, Raed A

2010-01-01

The aerospace industry requires the development of a range of chemical sensor technologies for such applications as leak detection, emission monitoring, fuel leak detection, environmental monitoring, and fire detection. A family of chemical sensors are being developed based on micromachining and microfabrication technology to fabricate microsensors with minimal size, weight, and power consumption, and the use of nanomaterials and structures to develop sensors with improved stability combined with higher sensitivity. However, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. These technologies and technical approaches have direct relevance to breath monitoring for clinical applications. This paper gives an overview of developing cutting-edge sensor technology and possible barriers to new technology implementation. This includes lessons learned from previous microsensor development, recent work in development of a breath monitoring system, and future directions in the implementation of cutting edge sensor technology. Clinical applications and the potential impact to the biomedical field of miniaturized smart gas sensor technology are discussed. PMID:20622933

Real-time monitoring of BTEX in air via ambient-pressure MPI

NASA Astrophysics Data System (ADS)

Swenson, Orven F.; Carriere, Josef P.; Isensee, Harlan; Gillispie, Gregory D.; Cooper, William F.; Dvorak, Michael A.

1998-05-01

We have developed and begun to field test a very sensitive method for real-time measurements of single-ring aromatic hydrocarbons in ambient air. In this study, we focus on the efficient 1 + 1 resonance enhanced multiphoton ionization (REMPI) of the BTEX species in the narrow region between 266 and 267 nm. We particularly emphasize 266.7 nm, a wavelength at which both benzene and toluene exhibit a sharp absorbance feature and benzene and its alkylated derivatives all absorb. An optical parametric oscillator system generating 266.7 nm, a REMPI cell, and digital oscilloscope detector are mounted on a breadboard attached to a small cart. In the first field test, the cart was wheeled through the various rooms of a chemistry research complex. Leakage of fuel through the gas caps of cars and light trucks in a parking lot was the subject of the second field test. The same apparatus was also used for a study in which the performance of the REMPI detector and a conventional photoionization detector were compared as a BTEX mixture was eluted by gas chromatography. Among the potential applications of the methodology are on-site analysis of combustion and manufacturing processes, soil gas and water headspace monitoring, space cabin and building air quality, and fuel leak detection.

Rapid Surface Detection of CO2 Leaks from Geologic Sequestration Sites

NASA Astrophysics Data System (ADS)

Moriarty, D. M.; Krevor, S. C.; Benson, S. M.

2013-12-01

Carbon sequestration is becoming a viable option for global CO2 mitigation but effective monitoring methods are needed assure the carbon dioxide stays underground. Above surface monitoring using a mobile gas analyzer is one such method (e.g. Krevor et al., 2010). The Picarro gas analyzer uses wavelength-scanned cavity ring down spectroscopy to accurately identify concentrations of various atmospheric gases including their isotopic composition. These measurements can then be used for anomaly (leak) detection and source attribution. Leaks are detected by anomalous absolute concentration of CO2 and anomalous δ13C values. Source attribution is determined by the isotopic concentrations of the identified leaking gas. To distinguish between noise from ambient signals and leaks, a method based on mixing ratios has been developed. A newly acquired data set presented here has been collected from a 3.7km2 area with naturally occurring CO2 springs near Green River, Utah. All of the areas of known leakage were readily detected using this method along with several other areas that showed significant signs of leakage. In addition, testing on the Stanford campus has shown that this method is sensitive enough to distinguish between open fields and roadways. Another data set is being collected at Montana State University at the ZERT monitoring test site where an artificial leak has been created for the purpose of testing leak detection and quantification methods. Data collected from this site are being used for (1) assessing of detection levels and how they depend on environmental parameters such as wind speed, and acquisition variables such as sample rate and traverse speed, (2) optimizing acquisition parameters to increase detection levels and increase confidence in leak detection, (3) evaluating the potential for quantifying the magnitude of the leak and (4) spatial data analysis to identify the most probable leak locations.

Vacuum decay container/closure integrity testing technology. Part 2. Comparison to dye ingress tests.

PubMed

Wolf, Heinz; Stauffer, Tony; Chen, Shu-Chen Y; Lee, Yoojin; Forster, Ronald; Ludzinski, Miron; Kamat, Madhav; Mulhall, Brian; Guazzo, Dana Morton

2009-01-01

Part 1 of this series demonstrated that a container closure integrity test performed according to ASTM F2338-09 Standard Test Method for Nondestructive Detection of Leaks in Packages by Vacuum Decay Method using a VeriPac 325/LV vacuum decay leak tester by Packaging Technologies & Inspection, LLC (PTI) is capable of detecting leaks > or = 5.0 microm (nominal diameter) in rigid, nonporous package systems, such as prefilled glass syringes. The current study compared USP, Ph.Eur. and ISO dye ingress integrity test methods to PTI's vacuum decay technology for the detection of these same 5-, 10-, and 15-microm laser-drilled hole defects in 1-mL glass prefilled syringes. The study was performed at three test sites using several inspectors and a variety of inspection conditions. No standard dye ingress method was found to reliably identify all holed syringes. Modifications to these standard dye tests' challenge conditions increased the potential for dye ingress, and adjustments to the visual inspection environment improved dye ingress detection. However, the risk of false positive test results with dye ingress tests remained. In contrast, the nondestructive vacuum decay leak test method reliably identified syringes with holes > or = 5.0 microm.

Eleventh interim status report: Model 9975 O-Ring fixture long-term leak performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W.

2016-08-01

A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determinemore » if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF.« less

Tenth interim status report: Model 9975 O-ring fixture long-term leak performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W. L.

2015-08-26

A series of experiments to monitor the aging performance of Viton ® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperatures. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 °F. They were leak-tested initially and have been tested periodically tomore » determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 °F.« less

Manual fire suppression methods on typical machinery space spray fires

NASA Astrophysics Data System (ADS)

Carhart, H. W.; Leonard, J. T.; Budnick, E. K.; Ouellette, R. J.; Shanley, J. H., Jr.

1990-07-01

A series of tests was conducted to evaluate the effectiveness of Aqueous Film Forming Foam (AFFF), potassium bicarbonate powder (PKP) and Halon 1211, alone and in various combinations, in extinguishing spray fires. The sprays were generated by JP-5 jet fuel issuing from an open sounding tube, and open petcock, a leaking flange or a slit pipe, and contacting an ignition source. The results indicate that typical fuel spray fires, such as those simulated in this series, are very severe. Flame heights ranged from 6.1 m (20 ft) for the split pipe to 15.2 m (50 ft) for the sounding tube scenario. These large flame geometries were accompanied by heat release rates of 6 MW to greater than 50 MW, and hazardous thermal radiation levels in the near field environment, up to 9.1 m (30 ft) away. Successful suppression of these fires requires both a significant reduction in flame radiation and delivery of a suppression agent to shielded areas. Of the nine suppression methods tested, the 95 gpm AFFF hand line and the hand line in conjunction with PKP were particularly effective in reducing the radiant flux.

Demonstration of rapid and sensitive module leak certification for space station freedom

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dietz, R.N.; Goodrich, R.W.

1991-03-01

A leak detection and quantification demonstration using perflurocarbon tracer (PFT) technology was successfully performed at the NASA Marshall Space Flight Center on January 25, 1991. The real-time Dual Trap Analyzer (DTA) at one-half hour after the start of the first run gave an estimated leak rate of 0.7 mL/min. This has since been refined to be 1.15 {plus minus} 0.09 mL/min. The leak rates in the next three runs were determined to be 9.8 {plus minus} 0.7, {minus}0.4 {plus minus} 0.3, and 76 {plus minus} 6 mL/min, respectively. The theory on leak quantification in the steady-state and time-dependent modes formore » a single zone test facility was developed and applied to the above determinations. The laboratory PFT analysis system gave a limit-of-detection (LOD) of 0.05 fL for ocPDCH. This is the tracer of choice and is about 100-fold better than that for the DTA. Applied to leak certification, the LOD is about 0.00002 mL/s (0.000075 L/h), a 5 order-of-magnitude improvement over the original leak certification specification. Furthermore, this limit can be attained in a measurement period of 3 to 4 hours instead of days, weeks, or months. A new Leak Certification Facility is also proposed to provide for zonal (three zones) determination of leak rates. The appropriate multizone equations, their solutions, and error analysis have already been derived. A new concept of seal-integrity certification has been demonstrated for a variety of controlled leaks in the range of module leak testing. High structural integrity leaks were shown to have a linear dependence of flow on {Delta}p. The rapid determination of leak rates at different pressures is proposed and is to be determined while subjecting the module to other external force-generating parameters such as vibration, torque, solar intensity, etc. 13 refs.« less

Demonstration of rapid and sensitive module leak certification for Space Station Freedom

NASA Technical Reports Server (NTRS)

Dietz, R. N.; Goodrich, R. W.

1991-01-01

A leak detection and quantification demonstration using perflurocarbon tracer (PFT) technology was successfully performed at the NASA Marshall Space Flight Center on January 25, 1991. The real-time Dual Trap Analyzer (DTA) at one-half hour after the start of the first run gave an estimated leak rate of 0.7 mL/min. This has since been refined to be 1.15 (+ or -) 0.09 mL/min. The leak rates in the next three runs were determined to be 9.8 (+ or -) 0.7, -0.4 (+ or -) 0.3, and 76 (+ or -) 6 mL/min, respectively. The theory on leak quantification in the steady-state and time-dependent modes for a single zone test facility was developed and applied to the above determinations. The laboratory PFT analysis system gave a limit-of-detection (LOD) of 0.05 fL for ocPDCH. This is the tracer of choice and is about 100-fold better than that for the DTA. Applied to leak certification, the LOD is about 0.00002 mL/s (0.000075 L/h), a 5 order-of-magnitude improvement over the original leak certification specification. Furthermore, this limit can be attained in a measurement period of 3 to 4 hours instead of days, weeks, or months. A new Leak Certification Facility is also proposed to provide for zonal (three zones) determination of leak rates. The appropriate multizone equations, their solutions, and error analysis have already been derived. A new concept of seal-integrity certification has been demonstrated for a variety of controlled leaks in the range of module leak testing. High structural integrity leaks were shown to have a linear dependence of flow on (Delta)p. The rapid determination of leak rates at different pressures is proposed and is to be determined while subjecting the module to other external force-generating parameters such as vibration, torque, solar intensity, etc.

Amylase in drain fluid for the diagnosis of pancreatic leak in post-pancreatic resection.

PubMed

Davidson, Tsetsegdemberel Bat-Ulzii; Yaghoobi, Mohammad; Davidson, Brian R; Gurusamy, Kurinchi Selvan

2017-04-07

The treatment of people with clinically significant postoperative pancreatic leaks is different from those without clinically significant pancreatic leaks. It is important to know the diagnostic accuracy of drain fluid amylase as a triage test for the detection of clinically significant pancreatic leaks, so that an informed decision can be made as to whether the patient with a suspected pancreatic leak needs further investigations and treatment. There is currently no systematic review of the diagnostic test accuracy of drain fluid amylase for the diagnosis of clinically relevant pancreatic leak. To determine the diagnostic accuracy of amylase in drain fluid at 48 hours or more for the diagnosis of pancreatic leak in people who had undergone pancreatic resection. We searched MEDLINE, Embase, the Science Citation Index Expanded, and the National Institute for Health Research Health Technology Assessment (NIHR HTA) websites up to 20 February 2017. We searched the references of the included studies to identify additional studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively. We also performed a 'related search' and 'citing reference' search in MEDLINE and Embase. We included all studies that evaluated the diagnostic test accuracy of amylase in the drain fluid at 48 hours or more for the diagnosis of pancreatic leak in people who had undergone pancreatic resection excluding total pancreatectomy. We planned to exclude case-control studies because these studies are prone to bias, but did not find any. At least two authors independently searched and screened the references produced by the search to identify relevant studies. Two review authors independently extracted data from the included studies. The included studies reported drain fluid amylase on different postoperative days and measured at different cut-off levels, so it was not possible to perform a meta-analysis using the bivariate model as planned. We have reported the sensitivity, specificity, post-test probability of a positive and negative drain fluid amylase along with 95% confidence interval (CI) on each of the different postoperative days and measured at different cut-off levels. A total of five studies including 868 participants met the inclusion criteria for this review. The five studies included in this review reported the value of drain fluid amylase at different thresholds and different postoperative days. The sensitivities and specificities were variable; the sensitivities ranged between 0.72 and 1.00 while the specificities ranged between 0.73 and 0.99 for different thresholds on different postoperative days. At the median prevalence (pre-test probability) of 15.9%, the post-test probabilities for pancreatic leak ranged between 35.9% and 95.4% for a positive drain fluid amylase test and ranged between 0% and 5.5% for a negative drain fluid amylase test.None of the studies used the reference standard of confirmation by surgery or by a combination of surgery and clinical follow-up, but used the International Study Group on Pancreatic Fistula (ISGPF) grade B and C as the reference standard. The overall methodological quality was unclear or high in all the studies. Because of the paucity of data and methodological deficiencies in the studies, we are uncertain whether drain fluid amylase should be used as a method for testing for pancreatic leak in an unselected population after pancreatic resection; and we judge that the optimal cut-off of drain fluid amylase for making the diagnosis of pancreatic leak is also not clear. Further well-designed diagnostic test accuracy studies with pre-specified index test threshold of drain fluid amylase (at three times more on postoperative day 5 or another suitable pre-specified threshold), appropriate follow-up (for at least six to eight weeks to ensure that there are no pancreatic leaks), and clearly defined reference standards (of surgical, clinical, and radiological confirmation of pancreatic leak) are important to reliably determine the diagnostic accuracy of drain fluid amylase in the diagnosis of pancreatic leak.

Hydrogen Sensors Boost Hybrids; Today's Models Losing Gas?

NASA Technical Reports Server (NTRS)

2005-01-01

Advanced chemical sensors are used in aeronautic and space applications to provide safety monitoring, emission monitoring, and fire detection. In order to fully do their jobs, these sensors must be able to operate in a range of environments. NASA has developed sensor technologies addressing these needs with the intent of improving safety, optimizing combustion efficiencies, and controlling emissions. On the ground, the chemical sensors were developed by NASA engineers to detect potential hydrogen leaks during Space Shuttle launch operations. The Space Shuttle uses a combination of hydrogen and oxygen as fuel for its main engines. Liquid hydrogen is pumped to the external tank from a storage tank located several hundred feet away. Any hydrogen leak could potentially result in a hydrogen fire, which is invisible to the naked eye. It is important to detect the presence of a hydrogen fire in order to prevent a major accident. In the air, the same hydrogen-leak dangers are present. Stress and temperature changes can cause tiny cracks or holes to form in the tubes that line the Space Shuttle s main engine nozzle. Such defects could allow the hydrogen that is pumped through the nozzle during firing to escape. Responding to the challenges associated with pinpointing hydrogen leaks, NASA endeavored to improve propellant leak-detection capabilities during assembly, pre-launch operations, and flight. The objective was to reduce the operational cost of assembling and maintaining hydrogen delivery systems with automated detection systems. In particular, efforts have been focused on developing an automated hydrogen leak-detection system using multiple, networked hydrogen sensors that are operable in harsh conditions.

Measurement of Submerged Oil/Gas Leaks using ROV Video

NASA Astrophysics Data System (ADS)

Shaffer, Franklin; de Vera, Giorgio; Lee, Kenneth; Savas, Ömer

2013-11-01

Drilling for oil or gas in the Gulf of Mexico is increasing rapidly at depths up to three miles. The National Commission on the Deepwater Horizon Oil Leak concluded that inaccurate estimates of the leak rate from the Deepwater Horizon caused an inadequate response and attempts to cap the leak to fail. The first response to a submerged oil/gas leak will be to send a Remotely Operated Vehicle (ROV) down to view the leak. During the response to the Deepwater Horizon crisis, the authors Savas and Shaffer were members of the Flow Rate Technical Group's Plume Team who used ROV video to develop the FRTG's first official estimates of the oil leak rate. Savas and Shaffer developed an approach using the larger, faster jet features (e.g., turbulent eddies, vortices, entrained particles) in the near-field developing zone to measure discharge rates. The authors have since used the Berkeley Tow Tank to test this approach on submerged dye-colored water jets and compressed air jets. Image Correlation Velocimetry has been applied to measure the velocity of visible features. Results from tests in the Berkeley Tow Tank and submerged oil jets in the OHMSETT facility will be presented.

Reusable Solid Rocket Motor Nozzle Joint-4 Thermal Analysis

NASA Technical Reports Server (NTRS)

Clayton, J. Louie

2001-01-01

This study provides for development and test verification of a thermal model used for prediction of joint heating environments, structural temperatures and seal erosions in the Space Shuttle Reusable Solid Rocket Motor (RSRM) Nozzle Joint-4. The heating environments are a result of rapid pressurization of the joint free volume assuming a leak path has occurred in the filler material used for assembly gap close out. Combustion gases flow along the leak path from nozzle environment to joint O-ring gland resulting in local heating to the metal housing and erosion of seal materials. Analysis of this condition was based on usage of the NASA Joint Pressurization Routine (JPR) for environment determination and the Systems Improved Numerical Differencing Analyzer (SINDA) for structural temperature prediction. Model generated temperatures, pressures and seal erosions are compared to hot fire test data for several different leak path situations. Investigated in the hot fire test program were nozzle joint-4 O-ring erosion sensitivities to leak path width in both open and confined joint geometries. Model predictions were in generally good agreement with the test data for the confined leak path cases. Worst case flight predictions are provided using the test-calibrated model. Analysis issues are discussed based on model calibration procedures.

40 CFR 63.1046 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Method 21 of 40 CFR part 60, appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak... 60, appendix A. (7) Each potential leak interface shall be checked by traversing the instrument probe...

40 CFR 63.1046 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Method 21 of 40 CFR part 60, appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak... 60, appendix A. (7) Each potential leak interface shall be checked by traversing the instrument probe...

40 CFR 63.1046 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Method 21 of 40 CFR part 60, appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak... 60, appendix A. (7) Each potential leak interface shall be checked by traversing the instrument probe...

40 CFR 63.945 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated... determined according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak...

40 CFR 63.945 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated... determined according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak...

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.905 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.925 - Test methods and procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated with... according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak interface...

40 CFR 63.945 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., appendix A. Each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices shall be checked. Potential leak interfaces that are associated... determined according to the procedures in Method 21 of 40 CFR part 60, appendix A. (7) Each potential leak...

40 CFR 63.1036 - Alternative means of emission limitation: Batch processes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SOURCE CATEGORIES (CONTINUED) National Emission Standards for Equipment Leaks-Control Level 2 Standards... leaks. The owner or operator may switch among the alternatives provided the change is documented as... shall be pressure-tested for leaks before regulated material is first fed to the equipment and the...

Silver plating technique seals leaks in thin wall tubing joints

NASA Technical Reports Server (NTRS)

Blenderman, W. H.

1966-01-01

Leaks in thin wall tubing joints are sealed by cleaning and silver plating the hot gas side of the joint in the leakage area. The pressure differential across the silver during hydrostatic test and subsequent use forces the ductile silver into the leak area and seals it.

Project W-314 acceptance test report HNF-4647 for HNF-4646 241-B pit leak detection ANB-WT-LDSTA-231 for project W-314

DOE Office of Scientific and Technical Information (OSTI.GOV)

HAMMERS, J.S.

The purpose of the test was to verify that the AN Tank Farm B Pit Leak Detector components are functionally integrated and operate in accordance with engineering design specifications. The Acceptance Test Procedure HNF-4646,241-AN-B-Pit Leak Detection ANB-WT-LDSTA-231 was conducted between 26 June and 02 July 1999 at the 200E AN Tank Farm. The test has been completed with no open test exceptions. The test was conducted prior to final engineering ''as built'' activities being completed this had no impact on the procedure or test results. All components, identified in the procedure were found to be labeled and identified as writtenmore » in the procedure.« less

A Hydrogen Leak Detection System for Aerospace and Commercial Applications

NASA Technical Reports Server (NTRS)

Hunter, Gary W.; Makel, D. B.; Jansa, E. D.; Patterson, G.; Cova, P. J.; Liu, C. C.; Wu, Q. H.; Powers, W. T.

1995-01-01

Leaks on the space shuttle while on the launch pad have generated interest in hydrogen leak monitoring technology. Microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC). These sensors have been integrated into hardware and software designed by Aerojet. This complete system allows for multipoint leak monitoring designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. This system is in operation in an automotive application which requires high sensitivity to hydrogen.

Leak Detection in Spacecraft Using a 64-Element Multiplexed Passive Array to Monitor Structure-Borne Noise

NASA Astrophysics Data System (ADS)

Holland, Stephen D.; Song, Jun-Ho; Chimenti, D. E.; Roberts, Ron

2006-03-01

We demonstrate an array sensor method intended to locate leaks in manned spacecraft using leak-generated, structure-borne ultrasonic noise. We have developed and tested a method for sensing and processing leak noise to reveal the leak location involving the use of a 64-element phased-array. Cross-correlations of ultrasonic noise waveforms from a leak into vacuum have been used with a phased-array analysis to find the direction from the sensor to the leak. This method measures the propagation of guided ultrasonic Lamb waves passing under the PZT array sensor in the spacecraft skin structure. This paper will describe the custom-designed array with integrated electronics, as well as the performance of the array in prototype applications. We show that this method can be used to successfully locate leaks to within a few millimeters on a 0.6-m square aluminum plate.

Small-target leak detection for a closed vessel via infrared image sequences

NASA Astrophysics Data System (ADS)

Zhao, Ling; Yang, Hongjiu

2017-03-01

This paper focus on a leak diagnosis and localization method based on infrared image sequences. Some problems on high probability of false warning and negative affect for marginal information are solved by leak detection. An experimental model is established for leak diagnosis and localization on infrared image sequences. The differential background prediction is presented to eliminate the negative affect of marginal information on test vessel based on a kernel regression method. A pipeline filter based on layering voting is designed to reduce probability of leak point false warning. A synthesize leak diagnosis and localization algorithm is proposed based on infrared image sequences. The effectiveness and potential are shown for developed techniques through experimental results.

Feasibility of an on-line fission-gas-leak detection system

NASA Technical Reports Server (NTRS)

Lustig, P. H.

1973-01-01

Calculations were made to determine if a cladding failure could be detected in a 100-kW zirconium hydride reactor primary system by monitoring the highly radioactive NaK coolant for the presence of I-131. The system is to be completely sealed. A leak of 0.01 percent from a single fuel pin was postulated. The 0.364-MeV gamma of I-131 could be monitored on an almost continuous basis, while its presence could be varified by using a longer counting time for the 0.638-MeV gamma. A lithium-drifted germanium detector would eliminate radioactive corrosion product interference that could occur with a sodium iodide scintillation detector.

KSC-2009-3828

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker examines the location of the quick disconnect on the Ground Umbilical Carrier Plate, or GUCP, being removed from space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2010-5636

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to remove the ground umbilical carrier plate (GUCP) from space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5625

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers remove the seal from the ground umbilical carrier plate (GUCP). A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

KSC-2009-3838

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker has removed the seal from the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2010-5643

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers install a cap over the hole in space shuttle Discovery's external fuel tank where the ground umbilical carrier plate (GUCP) was removed. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5637

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers begin to remove the ground umbilical carrier plate (GUCP) from space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-3822

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to remove the 7-inch quick disconnect on the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2009-3824

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers remove the 7-inch quick disconnect on the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2010-5641

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the ground umbilical carrier plate (GUCP) is ready to be examined. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5628

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers examine the seal from the ground umbilical carrier plate (GUCP). A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

KSC-2010-5624

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers begin to remove the seal from the ground umbilical carrier plate (GUCP). A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

KSC-2009-3823

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers remove the 7-inch quick disconnect on the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2010-5640

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers move the ground umbilical carrier plate (GUCP) to a location where it can be examined. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-3825

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers remove the 7-inch quick disconnect on the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2010-5642

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers install a cap over the hole in space shuttle Discovery's external fuel tank where the ground umbilical carrier plate (GUCP) was removed. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5635

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to remove the ground umbilical carrier plate (GUCP) from space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5626

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers examine the seal from the ground umbilical carrier plate (GUCP). A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

KSC-2009-3837

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker has removed the seal from the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2009-3836

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker removes the seal from the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2009-3827

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers remove the 7-inch quick disconnect from the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2009-3826

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker has removed the 7-inch quick disconnect from the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

KSC-2009-3835

NASA Image and Video Library

2009-06-24

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to remove the seal from the Ground Umbilical Carrier Plate, or GUCP, on space shuttle Endeavour's external fuel tank. A hydrogen leak at the location during tanking for the STS-127 mission caused the launch attempts to be scrubbed on June 13 and June 17. The GUCP will be examined to determine the cause of the hydrogen leak and repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Endeavour's next launch attempt is targeted for July 11 at 7:39 p.m. EDT. Photo credit: NASA/Jack Pfaller

105-KE Isolation Barrier Leak Rate Acceptance Test Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCracken, K.J.

1995-06-14

This Acceptance Test Report (ATR) contains the completed and signed Acceptance Procedure (ATP) for the 105-KE Isolations Barrier Leak Rate Test. The Test Engineer`s log, the completed sections of the ATP in the Appendix for Repeat Testing (Appendix K), the approved WHC J-7s (Appendix H), the data logger files (Appendices T and U), and the post test calibration checks (Appendix V) are included.

Endotracheal tube leak pressure and tracheal lumen size in swine.

PubMed

Finholt, D A; Audenaert, S M; Stirt, J A; Marcella, K L; Frierson, H F; Suddarth, L T; Raphaely, R C

1986-06-01

Endotracheal tube "leak" is often estimated in children to judge the fit of uncuffed endotracheal tubes within the trachea. Twenty-five swine were intubated with uncuffed tracheal tubes to determine whether a more sensitive measurement of leaks could be devised and whether leak pressure estimates fit between tracheal tube and trachea. We compared leak pressure measurement using a stethoscope and aneroid manometer with a technique using a microphone, pressure transducer, and recorder, and found no differences between the two methods. The tracheas were then removed and slides prepared of tracheal cross-sectional specimens. Regression analysis revealed a linear relationship between tracheal lumen size and tracheal tube size for both low leak pressure (y = -0.4 + 0.79x, r = 0.88, P less than 0.05) and high leak pressure (y = -2.9 + 0.71x, r = 0.92, P less than 0.05) groups. We conclude that leak testing with a stethoscope and aneroid manometer is sensitive and accurate, and that tracheal tube leak pressure accurately portrays fit between tube and trachea.

Primary flow meter for calibrating a sniffer test leak artefact by a pressure rise method

NASA Astrophysics Data System (ADS)

Arai, Kenta; Yoshida, Hajime

2014-10-01

Sniffer tests are used to locate leaks in equipment during operation. The sensitivity of a sniffer leak detector must be calibrated against a known gas flow to atmospheric pressure generated by a sniffer test leak artefact. We have developed a primary flow meter for calibrating gas flows to atmospheric pressure through the leak artefact. The flow meter is based on a pressure rise method and two chambers are used to measure the pressure rise with small uncertainty even at atmospheric pressure. The calibration range of the flow rate is 5 × 10-7 Pa m3 s-1 to 7 × 10-4 Pa m3 s-1 to atmospheric pressure at 23.0 °C with a minimum uncertainty of 1.4% (k = 2), as well as 4 × 10-8 Pa m3 s-1 to 5 × 10-4 Pa m3 s-1 to a vacuum at 23.0 °C. The long term stability of the flow meter was determined as 0.41% by repeated measurements of the conductance of the leak artefact. In case of the flow rate into a vacuum, the flow meter was successfully linked to the international reference value of CCM.P-K12 by a lab-internal comparison.

Bootstrap inversion technique for atmospheric trace gas source detection and quantification using long open-path laser measurements

NASA Astrophysics Data System (ADS)

Alden, Caroline B.; Ghosh, Subhomoy; Coburn, Sean; Sweeney, Colm; Karion, Anna; Wright, Robert; Coddington, Ian; Rieker, Gregory B.; Prasad, Kuldeep

2018-03-01

Advances in natural gas extraction technology have led to increased activity in the production and transport sectors in the United States and, as a consequence, an increased need for reliable monitoring of methane leaks to the atmosphere. We present a statistical methodology in combination with an observing system for the detection and attribution of fugitive emissions of methane from distributed potential source location landscapes such as natural gas production sites. We measure long (> 500 m), integrated open-path concentrations of atmospheric methane using a dual frequency comb spectrometer and combine measurements with an atmospheric transport model to infer leak locations and strengths using a novel statistical method, the non-zero minimum bootstrap (NZMB). The new statistical method allows us to determine whether the empirical distribution of possible source strengths for a given location excludes zero. Using this information, we identify leaking source locations (i.e., natural gas wells) through rejection of the null hypothesis that the source is not leaking. The method is tested with a series of synthetic data inversions with varying measurement density and varying levels of model-data mismatch. It is also tested with field observations of (1) a non-leaking source location and (2) a source location where a controlled emission of 3.1 × 10-5 kg s-1 of methane gas is released over a period of several hours. This series of synthetic data tests and outdoor field observations using a controlled methane release demonstrates the viability of the approach for the detection and sizing of very small leaks of methane across large distances (4+ km2 in synthetic tests). The field tests demonstrate the ability to attribute small atmospheric enhancements of 17 ppb to the emitting source location against a background of combined atmospheric (e.g., background methane variability) and measurement uncertainty of 5 ppb (1σ), when measurements are averaged over 2 min. The results of the synthetic and field data testing show that the new observing system and statistical approach greatly decreases the incidence of false alarms (that is, wrongly identifying a well site to be leaking) compared with the same tests that do not use the NZMB approach and therefore offers increased leak detection and sizing capabilities.

Aircraft accident report: NASA 712, Convair 990, N712NA, March Air Force Base, California, July 17, 1985, executive summary

NASA Technical Reports Server (NTRS)

Batthauer, Byron E.; Mccarthy, G. T.; Hannah, Michael; Hogan, Robert J.; Marlow, Frank J.; Reynard, William D.; Stoklosa, Janis H.; Yager, Thomas J.

1986-01-01

On July 17, l985, NASA 712, a Convair 990 aircraft, was destroyed by fire during an aborted takeoff at March Air Force Base in California. Material ejected from a blowout in the tires of the right main landing gear penetrated the right-wing fuel tank. The leaking fuel ignited. Fire engulfed the right wing and fuselage as the aircraft stopped its forward motion. The crew of four and the 15 scientists and technicians aboard escaped without serious injury.

EVALUATION OF SOIL WASHING TECHNOLOGY: RESULTS OF BENCH SCALE EXPERIMENTS ON PETROLEUM FUELS CONTAMINATED SOILS - EPA/600/S2-91/023

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) through its Risk Reduction Engineering Laboratory's Release Control Branch has undertaken research and development efforts to address the problem of leaking underground storage tanks (USTs). Under this effort, EPA is currently eva...

77 FR 9847 - Safety Zone; Kinnickinnic River Containment and Cleanup; Milwaukee, WI

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-21

... entering the Kinnickinnic River from an underground fuel leak in the vicinity of the airport in Milwaukee... That Significantly Affect Energy Supply, Distribution, or Use. We have determined that it is not a... Executive Order 12866 and is not likely to have a significant adverse effect on the supply, distribution, or...

77 FR 65805 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-31

.... ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all The Boeing... current high frequency (ETHF) inspections for cracking on the aft side of the left and right wing rear... and correct cracking of the left and right rear spar lower caps, which could result in fuel leaks and...

NASA/MSFC multilayer diffusion models and computer program for operational prediction of toxic fuel hazards

NASA Technical Reports Server (NTRS)

Dumbauld, R. K.; Bjorklund, J. R.; Bowers, J. F.

1973-01-01

The NASA/MSFC multilayer diffusion models are discribed which are used in applying meteorological information to the estimation of toxic fuel hazards resulting from the launch of rocket vehicle and from accidental cold spills and leaks of toxic fuels. Background information, definitions of terms, description of the multilayer concept are presented along with formulas for determining the buoyant rise of hot exhaust clouds or plumes from conflagrations, and descriptions of the multilayer diffusion models. A brief description of the computer program is given, and sample problems and their solutions are included. Derivations of the cloud rise formulas, users instructions, and computer program output lists are also included.

National Aerospace Plane Integrated Fuselage/Cryotank Risk Reduction program

NASA Astrophysics Data System (ADS)

Dayton, K. E.

1993-06-01

The principal objectives and results of the National Aerospace Plane (NASP) Integrated Risk Reduction program are briefly reviewed. The program demonstrated the feasibility of manufacturing lightweight advanced composite materials for single-stage-to-orbit hypersonic flight vehicle applications. A series of combined load simulation tests (thermal, mechanical, and cryogenic) demonstrated proof of concept performance for an all unlined composite cryogenic fuel tank with flat end bulkheads and a high-temperature thin-shell advanced composite fuselage. Temperatures of the fuselage were as high as 1300 F, with 100 percent bending and shear loads applied to the tank while filled with 850 gallons of cryogenic fluid hydrogen (-425 F). Leak rates measured on and around the cryotank shell and bulkheads were well below acceptable levels.

Superfluid helium leak sealant study

NASA Technical Reports Server (NTRS)

Vorreiter, J. W.

1981-01-01

Twenty-one leak specimens were fabricated in the ends of stainless steel and aluminum tubes. Eighteen of these tubes were coated with a copolymer material to seal the leak. The other three specimens were left uncoated and served as control specimens. All 21 tubes were cold shocked in liquid helium 50 times and then the leak rate was measured while the tubes were submerged in superfluid helium at 1.7 K. During the cold shocks two of the coated specimens were mechanically damaged and eliminated from the test program. Of the remaining 16 coated specimens one suffered a total coating failure and resulting high leak rate. Another three of the coated specimens suffered partial coating failures. The leak rates of the uncoated specimens were also measured and reported. The significance of various leak rates is discussed in view of the infrared astronomical satellite (IRAS) Dewar performance.

Delineation of ground-water contamination using soil-gas analyses near Jackson, Tennessee

USGS Publications Warehouse

Lee, R.W.

1991-01-01

An investigation of the ground-water resources near Jackson, West Tennessee, was conducted during 1988-89. The study included determination of the occurrence of contaminants in the shallow aquifer using soil-gas analyses in the unsaturated zone. Between 1980 and 1988, an underground fuel-storage tank leaked about 3,000 gallons of unleaded fuel to the water table about 4 feet below land surface. A survey of soil gas using a gas chromatograph equipped with a photoionization detector showed concentrations of volatile organic compounds greater than IO, 000 parts per million near the leak These compounds were detected in an area about 240 feet long and 110 feet wide extending west from the point source. The chromatograms provided two distinct 'fingerprints' of volatile organic compounds. The first revealed the presence of benzene, toluene, andxylenes, which are constituents of unleaded fuel, in addition to other volatile compounds, in soil gas in the area near the leak The second did not reveal any detectable benzene, toluene, or xylenes in the soil-gas samples, but showed the presence of other unidentified volatile organic compounds in soil gas north of the storage tank. The distribution of total concentrations of volatile organic compounds in the unsaturated zone indicated that a second plume about 200 feet long and 90 feet wide was present about 100 feet north of the storage tank The second plume could have been the result of previous activities at this site during the 1950's or earlier. Activities at the site are believed to have included storage of solvents used at the nearby railyard and flushing of tanks containing tar onto a gravel-covered parking area. The delineation of these plumes has shown that soil-gas analyses can be a useful technique for identifying areas of contamination with volatile organic compounds in shallow water-table aquifers and may have broad applications in similar situations where the water table is relatively close to the surface.

Pressure Decay Testing Methodology for Quantifying Leak Rates of Full-Scale Docking System Seals

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H., Jr.; Daniels, Christopher C.; Wasowski, Janice L.; Garafolo, Nicholas G.; Penney, Nicholas; Steinetz, Bruce M.

2010-01-01

NASA is developing a new docking system to support future space exploration missions to low-Earth orbit and the Moon. This system, called the Low Impact Docking System, is a mechanism designed to connect the Orion Crew Exploration Vehicle to the International Space Station, the lunar lander (Altair), and other future Constellation Project vehicles. NASA Glenn Research Center is playing a key role in developing the main interface seal for this docking system. This seal will be relatively large with an outside diameter in the range of 54 to 58 in. (137 to 147 cm). As part of this effort, a new test apparatus has been designed, fabricated, and installed to measure leak rates of candidate full-scale seals under simulated thermal, vacuum, and engagement conditions. Using this test apparatus, a pressure decay testing and data processing methodology has been developed to quantify full-scale seal leak rates. Tests performed on untreated 54 in. diameter seals at room temperature in a fully compressed state resulted in leak rates lower than the requirement of less than 0.0025 lbm, air per day (0.0011 kg/day).

VOLUMETRIC LEAK DETECTION IN LARGE UNDERGROUND STORAGE TANKS - VOLUME II: APPENDICES A-E

EPA Science Inventory

The program of experiments conducted at Griffiss Air Force Base was devised to expand the understanding of large underground storage tank behavior as it impacts the performance of volumetric leak detection testing. The report addresses three important questions about testing the ...

KSC-2010-5843

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians removed a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5842

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians remove a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5841

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians remove a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5840

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians remove a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5838

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians remove a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5839

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians remove a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5836

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians remove a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

KSC-2010-5837

NASA Image and Video Library

2010-12-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians remove a few items from space shuttle Discovery's middeck payload, including food, prior to a tanking test planned for no earlier than Dec. 15. During the test, engineers will monitor what happens to the external fuel tank's newly replaced ground umbilical carrier plate (GUCP) and the intertank's stringers, which are 21-foot long, U-shaped aluminum brackets located on the intertank, during loading of cryogenic propellants. Technicians already installed environmental enclosures on the tank, removed foam and prepared the tank's skin for approximately 89 strain gauges and thermocouples. Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at GUCP. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Ben Smegelsky

Controlling air leaks using free pericardial fat pads as surgical sealant in pulmonary resection.

PubMed

Ikeda, Takeshi; Sasaki, Masato; Yamada, Narihisa; Takamori, Atsushi; Tanabe, Sawaka; Okada, Akitoshi; Sakon, Kayo; Mizunaga, Tae; Koshiji, Takaaki

2015-04-01

This study evaluated the feasibility and efficacy of a new operative method for controlling intraoperative air leaks using free pericardial fat pads as a covering sealant in pulmonary resection. To manage air leaks that must be controlled in pulmonary resection at the first water sealing test, collected free pericardial fat was used as a covering sealant and sewn on by the suture closing the lesion. In cases of uncontrolled air leaks at the second sealing test, fibrin glue was used to fill the residual lesion between the fat and visceral pleura. Fifty-one eligible patients were enrolled in this study to evaluate the duration of postoperative air leaks and the condition of the implanted fat on chest computed tomography (CT) 6 months later. The mean duration of postoperative air leaks was 1.05 ± 1.84 days in the 39 cases that received the pericardial fat covering technique only and 2.66 ± 3.42 days in the 12 cases that received the pericardial fat covering technique combined with fibrin glue. Prolonged alveolar air leaks occurred in 1 case and 2 cases, respectively. No cases required conversion to conventional methods, and there were no further adverse events. On follow-up chest CT approximately 62.7% of obvious engrafted fat survived. Using free pericardial fat pads as a sealant to control air leaks in pulmonary resection is safe and has good feasibility and potent efficacy. This new method can be an innovative technique for preventing prolonged air leaks. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Greenhouse gas impacts of natural gas: Influence of deployment choice, methane leak rate, and methane GWP

NASA Astrophysics Data System (ADS)

Cohan, D. S.

2015-12-01

Growing supplies of natural gas have heightened interest in the net impacts of natural gas on climate. Although its production and consumption result in greenhouse gas emissions, natural gas most often substitutes for other fossil fuels whose emission rates may be higher. Because natural gas can be used throughout the sectors of the energy economy, its net impacts on greenhouse gas emissions will depend not only on the leak rates of production and distribution, but also on the use for which natural gas is substituted. Here, we present our estimates of the net greenhouse gas emissions impacts of substituting natural gas for other fossil fuels for five purposes: light-duty vehicles, transit buses, residential heating, electricity generation, and export for electricity generation overseas. Emissions are evaluated on a fuel cycle basis, from production and transport of each fuel through end use combustion, based on recent conditions in the United States. We show that displacement of existing coal-fired electricity and heating oil furnaces yield the largest reductions in emissions. The impact of compressed natural gas replacing petroleum-based vehicles is highly uncertain, with the sign of impact depending on multiple assumptions. Export of liquefied natural gas for electricity yields a moderate amount of emissions reductions. We further show how uncertainties in upstream emission rates for natural gas and in the global warming potential of methane influence the net greenhouse gas impacts. Our presentation will make the case that how natural gas is deployed is crucial to determining how it will impact climate.

40 CFR 265.191 - Assessment of existing tank system's integrity.

Code of Federal Regulations, 2010 CFR

2010-07-01

...); and (5) Results of a leak test, internal inspection, or other tank integrity examination such that: (i) For non-enterable underground tanks, this assessment must consist of a leak test that is capable of... water table effects, (ii) For other than non-enterable underground tanks and for ancillary equipment...

40 CFR 264.191 - Assessment of existing tank system's integrity.

Code of Federal Regulations, 2010 CFR

2010-07-01

...); and (5) Results of a leak test, internal inspection, or other tank integrity examination such that: (i) For non-enterable underground tanks, the assessment must include a leak test that is capable of taking into account the effects of temperature variations, tank end deflection, vapor pockets, and high water...

A proposed rationale and test methodology for establishment of acceptance criteria for vacuum integrity testing of pharmaceutical freeze dryers.

PubMed

Hardwick, Lisa M; Nail, Steven L; Jarman, James; Hasler, Kai; Hense, Thomas

2013-10-01

A scientific rationale is proposed for the establishment of acceptance criteria for leak rates in pharmaceutical freeze dryers. A method was developed to determine the quantity of air that could leak into any lyophilizer from the outside while still maintaining Class 100/Grade A microbial conditions. A lyophilizing product is assumed most vulnerable to microbial contamination during secondary drying, when mass transfer of water vapor from product to condenser is minimal. Using the void volume of the dryer, calculated from change in internal pressure when a known volume of air is introduced, and the potential maximum bioburden of the leaked air (based on measured values), calculations can determine the allowable leaked volume of air, the flow rate required to admit that volume in a given time frame, and the pressure rise that would result from the leak over a given testing period. For the dryers in this study, using worst-case air quality conditions, it was determined that a leak resulting in a pressure rise of 0.027 mbar over a 30 min period would allow the dryers to remain in secondary drying conditions for 62 h before the established action level of one colony forming unit for each cubic meter of air space would be reached. Copyright © 2013 Elsevier B.V. All rights reserved.

“A System for Automatically Maintaining Pressure in a Commercial Truck Tire”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maloney, John

2017-07-07

Under-inflated tires significantly reduce a vehicle’s fuel efficiency by increasing rolling resistance (drag force). The Air Maintenance Technology (“AMT”) system developed through this project replenishes lost air and maintains optimal tire cavity pressure whenever the tire is rolling in service, thus improving overall fuel economy by reducing the tire’s rolling resistance. The system consists of an inlet air filter, an air pump driven by tire deformation during rotation, and a pressure regulating device. Pressurized air in the tire cavity naturally escapes by diffusion through the tire and wheel, leaks in tire seating, and through the filler valve and its seating.more » As a result, tires require constant maintenance to replenish lost air. Since manual tire inflation maintenance is both labor intensive and time consuming, it is frequently overlooked or ignored. By automating the maintenance of optimal tire pressure, the tire’s contribution to the vehicle’s overall fuel economy can be maximized. The work was divided into three phases. The objectives of Phase 1, Planning and Initial Design, resulted in an effective project plan and to create a baseline design. The objectives for Phase 2, Design and Process Optimization, were: to identify finalized design for the pump, regulator and filter components; identify a process to build prototype tires; assemble prototype tires; test prototype tires and document results. The objectives of Phase 3, Design Release and Industrialization, were to finalize system tire assembly, perform release testing and industrialize the assembly process.« less

Leak detectability of the Norman Wells pipeline by mass balance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liou, J.C.P.

Pipeline leak detection using software-based systems is becoming common practice. The detectability of such systems is measured by how small and how quickly a leak can be detected. Algorithms used and measurement uncertainties determine leak detectability. This paper addresses leak detectability using mass balance, establishes leak detectability for Norman Wells pipelines, and compares it with field leak test results. The pipeline is operated by the Interprovincial Pipe Line (IPL) Inc., of Edmonton, Canada. It is a 12.75-inch outside diameter steel pipe with variable wall thickness. The length of the pipe is approximately 550 miles (868.9 km). The pipeline transports lightmore » crude oil at a constant flow rate of about 250 m{sup 3}/hr. The crude oil can enter the pipeline at two locations. Besides the Norman Wells inlet, there is a side line near Zama terminal that can inject crude oil into the pipeline.« less

40 CFR Appendix K to Part 75 - Quality Assurance and Operating Procedures for Sorbent Trap Monitoring Systems

Code of Federal Regulations, 2010 CFR

2010-07-01

... until the leak check is passed. Post-test leak check ≤4% of average sampling rate After sampling ** See... the test site. The sorbent media must be obtained from a source that can demonstrate the quality...-traceable calibration gas standards and reagents shall be used for the tests and procedures required under...

Electrochemical fuel cell generator having an internal and leak tight hydrocarbon fuel reformer

DOEpatents

Dederer, J.T.; Hager, C.A.

1998-03-31

An electrochemical fuel cell generator configuration is made having a generator section which contains a plurality of axially elongated fuel cells, each cell containing a fuel electrode, air electrode, and solid oxide electrolyte between the electrodes, in which axially elongated dividers separate portions of the fuel cells from each other, and where at least one divider also reforms a reformable fuel gas mixture prior to electricity generation reactions, the at least one reformer-divider is hollow having a closed end and an open end entrance for a reformable fuel mixture to pass to the closed end of the divider and then reverse flow and pass back along the hollowed walls to be reformed, and then finally to pass as reformed fuel out of the open end of the divider to contact the fuel cells, and further where the reformer-divider is a composite structure having a gas diffusion barrier of metallic foil surrounding the external walls of the reformer-divider except at the entrance to prevent diffusion of the reformable gas mixture through the divider, and further housed in an outer insulating jacket except at the entrance to prevent short-circuiting of the fuel cells by the gas diffusion barrier. 10 figs.

Electrochemical fuel cell generator having an internal and leak tight hydrocarbon fuel reformer

DOEpatents

Dederer, Jeffrey T.; Hager, Charles A.

1998-01-01

An electrochemical fuel cell generator configuration is made having a generator section which contains a plurality of axially elongated fuel cells, each cell containing a fuel electrode, air electrode, and solid oxide electrolyte between the electrodes, in which axially elongated dividers separate portions of the fuel cells from each other, and where at least one divider also reforms a reformable fuel gas mixture prior to electricity generation reactions, the at least one reformer-divider is hollow having a closed end and an open end entrance for a reformable fuel mixture to pass to the closed end of the divider and then reverse flow and pass back along the hollowed walls to be reformed, and then finally to pass as reformed fuel out of the open end of the divider to contact the fuel cells, and further where the reformer-divider is a composite structure having a gas diffusion barrier of metallic foil surrounding the external walls of the reformer-divider except at the entrance to prevent diffusion of the reformable gas mixture through the divider, and further housed in an outer insulating jacket except at the entrance to prevent short-circuiting of the fuel cells by the gas diffusion barrier.

High-sensitivity Leak-testing Method with High-Resolution Integration Technique

NASA Astrophysics Data System (ADS)

Fujiyoshi, Motohiro; Nonomura, Yutaka; Senda, Hidemi

A high-resolution leak-testing method named HR (High-Resolution) Integration Technique has been developed for MEMS (Micro Electro Mechanical Systems) sensors such as a vibrating angular-rate sensor housed in a vacuum package. Procedures of the method to obtain high leak-rate resolution were as follows. A package filled with helium gas was kept in a small accumulation chamber to accumulate helium gas leaking from the package. After the accumulation, the accumulated helium gas was introduced into a mass spectrometer in a short period of time, and the flux of the helium gas was measured by the mass spectrometer as a transient phenomenon. The leak-rate of the package was calculated from the detected transient waveform of the mass spectrometer and the accumulation time of the helium gas in the accumulation chamber. Because the density of the helium gas in the vacuum chamber increased and the accumulated helium gas was measured in a very short period of time with the mass spectrometer, the peak strength of the transient waveform became high and the signal to noise ratio was much improved. The detectable leak-rate resolution of the technique reached 1×10-15 (Pa·m3/s). This resolution is 103 times superior to that of the conventional helium vacuum integration method. The accuracy of the measuring system was verified with a standard helium gas leak source. The results were well matched between theoretical calculation based on the leak-rate of the source and the experimental results within only 2% error.

Testing of heat exchangers in membrane oxygenators using air pressure.

PubMed

Hamilton, Carole; Stein, Jutta; Seidler, Rainer; Kind, Robert; Beck, Karin; Tosok, Jürgen; Upterfofel, Jörg

2006-03-01

All heat exchangers (HE) in membrane oxygenators are tested by the manufacturer for water leaks during the production phase. However, for safety reasons, it is highly recommended that HEs be tested again before clinical use. The most common method is to attach the heater-cooler to the HE and allow the water to recirculate for at least 10 min, during which time a water leak should be evident. To improve the detection of water leaks, a test was devised using a pressure manometer with an integrated bulb used to pressurize the HE with air. The cardiopulmonary bypass system is set up as per protocol. A pressure manometer adapted to a 1/2" tubing is connected to the water inlet side of the oxygenator. The water outlet side is blocked with a short piece of 1/2" deadend tubing. The HE is pressurized with 250 mmHg for at least 30 sec and observed for any drop. Over the last 2 years, only one oxygenator has been detected with a water leak in which the air-method leaktest was performed. This unit was sent back to the manufacturer who confirmed the failure. Even though the incidence of water leaks is very low, it does occur and it is, therefore, important that all HEs are tested before they are used clinically. This method of using a pressure manometer offers many advantages, as the HE can be tested outside of the operating room (OR), allowing earlier testing of the oxygenator, no water contact is necessary, and it is simple, easy and quick to perform.

Assessment of crash fire hazard of LH sub 2 fueled aircraft

NASA Technical Reports Server (NTRS)

Brewer, G. D.; Wittlin, G.; Versaw, E. F.; Parmley, R.; Cima, R.; Walther, E. G.

1981-01-01

The relative safety of passengers in LH2 - fueled aircraft, as well as the safety of people in areas surrounding a crash scene, has been evaluated in an analytical study. Four representative circumstances were postulated involving a transport aircraft in which varying degrees of severity of damage were sustained. Potential hazard to the passengers and to the surroundings posed by the spilled fuel was evaluated for each circumstance. Corresponding aircraft fueled with liquid methane, Jet A, and JP-4 were also studied in order to make comparisons of the relative safety. The four scenarios which were used to provide a basis for the evaluation included: (1) a small fuel leak internal to the aircraft, (2) a survivable crash in which a significant quantity of fuel is spilled in a radial pattern as a result of impact with a stationary object while taxiing at fairly low speed, (3) a survivable crash in which a significant quantity of fuel is spilled in an axial pattern as a result of impact during landing, and (4) a non-survivable crash in which a massive fuel spill occurs instantaneously.

Chitosan and alginate types of bio-membrane in fuel cell application: An overview

NASA Astrophysics Data System (ADS)

Shaari, N.; Kamarudin, S. K.

2015-09-01

The major problems of polymer electrolyte membrane fuel cell technology that need to be highlighted are fuel crossovers (e.g., methanol or hydrogen leaking across fuel cell membranes), CO poisoning, low durability, and high cost. Chitosan and alginate-based biopolymer membranes have recently been used to solve these problems with promising results. Current research in biopolymer membrane materials and systems has focused on the following: 1) the development of novel and efficient biopolymer materials; and 2) increasing the processing capacity of membrane operations. Consequently, chitosan and alginate-based biopolymers seek to enhance fuel cell performance by improving proton conductivity, membrane durability, and reducing fuel crossover and electro-osmotic drag. There are four groups of chitosan-based membranes (categorized according to their reaction and preparation): self-cross-linked and salt-complexed chitosans, chitosan-based polymer blends, chitosan/inorganic filler composites, and chitosan/polymer composites. There are only three alginate-based membranes that have been synthesized for fuel cell application. This work aims to review the state-of-the-art in the growth of chitosan and alginate-based biopolymer membranes for fuel cell applications.

Leak Mitigation in Mechanically Pumped Fluid Loops for Long Duration Space Missions

NASA Technical Reports Server (NTRS)

Miller, Jennifer R.; Birur, Gajanana; Bame, David; Mastropietro, A. J.; Bhandari, Pradeep; Lee, Darlene; Karlmann, Paul; Liu, Yuanming

2013-01-01

Mechanically pumped fluid loops (MPFLs) are increasingly considered for spacecraft thermal control. A concern for long duration space missions is the leak of fluid leading to performance degradation or potential loop failure. An understanding of leak rate through analysis, as well as destructive and non-destructive testing, provides a verifiable means to quantify leak rates. The system can be appropriately designed to maintain safe operating pressures and temperatures throughout the mission. Two MPFLs on the Mars Science Laboratory Spacecraft, launched November 26, 2011, maintain the temperature of sensitive electronics and science instruments within a -40 deg C to 50 deg C range during launch, cruise, and Mars surface operations. With over 100 meters of complex tubing, fittings, joints, flex lines, and pumps, the system must maintain a minimum pressure through all phases of the mission to provide appropriate performance. This paper describes the process of design, qualification, test, verification, and validation of the components and assemblies employed to minimize risks associated with excessive fluid leaks from pumped fluid loop systems.

40 CFR 60.482-2 - Standards: Pumps in light liquid service.

Code of Federal Regulations, 2011 CFR

2011-07-01

...; or (ii) Equipped with a barrier fluid degassing reservoir that is routed to a process or fuel gas... in VOC service. (3) Each barrier fluid system is equipped with a sensor that will detect failure of...) Designate the visual indications of liquids dripping as a leak. (5)(i) Each sensor as described in paragraph...

40 CFR 60.482-2 - Standards: Pumps in light liquid service.

Code of Federal Regulations, 2010 CFR

2010-07-01

...; or (ii) Equipped with a barrier fluid degassing reservoir that is routed to a process or fuel gas... in VOC service. (3) Each barrier fluid system is equipped with a sensor that will detect failure of...) Designate the visual indications of liquids dripping as a leak. (5)(i) Each sensor as described in paragraph...

40 CFR 63.163 - Standards: Pumps in light liquid service.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Equipped with a barrier fluid degassing reservoir that is routed to a process or fuel gas system or... with a sensor that will detect failure of the seal system, the barrier fluid system, or both. (4) Each... per million or greater is measured, a leak is detected. (5) Each sensor as described in paragraph (e...

24 CFR 3280.706 - Oil piping systems.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the Standard Specification for Seamless Copper Water Tube, ASTM B88-93, or shall comply with ASTM B280... supply connection(s) shall be rigidly anchored to a structural member within 6 inches of the supply... shall be checked for oil leaks with fuel oil of the same grade that will be burned in the appliance. No...

AGR-1 Irradiation Test Final As-Run Report, Rev. 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collin, Blaise P.

2015-01-01

This document presents the as-run analysis of the AGR-1 irradiation experiment. AGR-1 is the first of eight planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the US Department of Energy (DOE) as part of the Next-Generation Nuclear Plant (NGNP) project. The objectives of the AGR-1 experiment are: 1. To gain experience with multi-capsule test train design, fabrication, and operation with the intent to reduce the probability of capsule or test train failure in subsequent irradiation tests. 2. To irradiate fuel produced in conjunction with the AGR fuel processmore » development effort. 3. To provide data that will support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. In order to achieve the test objectives, the AGR-1 experiment was irradiated in the B-10 position of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) for a total duration of 620 effective full power days of irradiation. Irradiation began on December 24, 2006 and ended on November 6, 2009 spanning 13 ATR cycles and approximately three calendar years. The test contained six independently controlled and monitored capsules. Each capsule contained 12 compacts of a single type, or variant, of the AGR coated fuel. No fuel particles failed during the AGR-1 irradiation. Final burnup values on a per compact basis ranged from 11.5 to 19.6 %FIMA, while fast fluence values ranged from 2.21 to 4.39 x 10 25 n/m 2 (E >0.18 MeV). We’ll say something here about temperatures once thermal recalc is done. Thermocouples performed well, failing at a lower rate than expected. At the end of the irradiation, nine of the originally-planned 19 TCs were considered functional. Fission product release-to-birth (R/B) ratios were quite low. In most capsules, R/B values at the end of the irradiation were at or below 10 -7 with only one capsule significantly exceeding this value. A maximum R/B of around 2 x 10 -7 was reached at the end of the irradiation in Capsule 5. Several shakedown issues were encountered and resolved during the first three cycles. These include the repair of minor gas line leaks; repair of faulty gas line valves; the need to position moisture monitors in regions of low radiation fields for proper functioning; the enforcement of proper on-line data storage and backup, the need to monitor thermocouple performance, correcting for detector spectral gain shift, and a change in the mass flow rate range of the neon flow controllers.« less

The development of hydrogen sensor technology at NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Hunter, Gary W.; Neudeck, Philip G.; Jefferson, G. D.; Madzsar, G. C.; Liu, C. C.; Wu, Q. H.

1993-01-01

The detection of hydrogen leaks in aerospace applications, especially those involving hydrogen fuel propulsion systems, is of extreme importance for reasons of reliability, safety, and economy. Motivated by leaks occurring in liquid hydrogen lines supplying the main engine of the Space Shuttle, NASA Lewis has initiated a program to develop point-contact hydrogen sensors which address the needs of aerospace applications. Several different approaches are being explored. They include the fabrication of PdAg Schottky diode structures, the characterization of PdCr as a hydrogen sensitive alloy, and the use of SiC as a semiconductor for hydrogen sensors. This paper discusses the motivation behind and present status of each of the major components of the NASA LeRC hydrogen sensor program.

KSC-2010-5622

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers will focus their attention on the ground umbilical carrier plate (GUCP), which is on space shuttle Discovery's orange external fuel tank at the end of the access arm. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

KSC-2010-5623

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers are focusing their attention on the ground umbilical carrier plate (GUCP), which is on space shuttle Discovery's orange external fuel tank at the end of the access arm. A hydrogen gas leak at that location during tanking for Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

STS-35 Columbia, OV-102, rolls back to KSC VAB after hydrogen leak discovered

NASA Image and Video Library

1990-06-12

S90-42289 ( 3 July 1990) --- Kennedy Space Center (KSC) workers watch as Columbia, Orbiter Vehicle (OV) 102, along with its external tank (ET) and two solid rocket boosters (SRBs) atop the giant crawler transporter, rolls back to KSC's Vehicle Assembly Building (VAB). The rollback was caused by a hydrogen leak that stopped the STS-35 countdown during ET fueling, 05-29-90. Once in the VAB, OV-102 and its stack will be demated, and OV-102, with its Astronomy Laboratory 1 (ASTRO-1) payload aboard, will be moved to the Orbiter Processing Facility (OPF) to await return to KSC Launch Complex (LC) Pad 39A. View provided by KSC with alternate number KSC-90PC-901.

Fault tree analysis of fire and explosion accidents for dual fuel (diesel/natural gas) ship engine rooms

NASA Astrophysics Data System (ADS)

Guan, Yifeng; Zhao, Jie; Shi, Tengfei; Zhu, Peipei

2016-09-01

In recent years, China's increased interest in environmental protection has led to a promotion of energy-efficient dual fuel (diesel/natural gas) ships in Chinese inland rivers. A natural gas as ship fuel may pose dangers of fire and explosion if a gas leak occurs. If explosions or fires occur in the engine rooms of a ship, heavy damage and losses will be incurred. In this paper, a fault tree model is presented that considers both fires and explosions in a dual fuel ship; in this model, dual fuel engine rooms are the top events. All the basic events along with the minimum cut sets are obtained through the analysis. The primary factors that affect accidents involving fires and explosions are determined by calculating the degree of structure importance of the basic events. According to these results, corresponding measures are proposed to ensure and improve the safety and reliability of Chinese inland dual fuel ships.

IMPACT OF FISSION PRODUCTS IMPURITY ON THE PLUTONIUM CONTENT IN PWR MOX FUELS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilles Youinou; Andrea Alfonsi

2012-03-01

This report presents the results of a neutronics analysis done in response to the charter IFCA-SAT-2 entitled 'Fuel impurity physics calculations'. This charter specifies that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies (UOX SNF) is not perfect and that, consequently, a certain amount of FP goes into the Pu stream used to fabricate PWR MOX fuel assemblies. Only non-gaseous FP have been considered (see the list of 176 isotopes considered in the calculations in Appendix 1). This mixture of Pu and FP is called PuFP. Note that, in this preliminary analysis,more » the FP losses are considered element-independent, i.e., for example, 1% of FP losses mean that 1% of all non-gaseous FP leak into the Pu stream.« less

KSC-2010-5884

NASA Image and Video Library

2010-12-17

CAPE CANAVERAL, Fla. -- Team members stationed at consoles in the Launch Control Center at NASA's Kennedy Space Center in Florida monitor space shuttle Discovery's external fuel tank as it is loaded with more than 535,000 gallons of cryogenic propellants. From back, are STS-133 Assistant NASA Test Director Jeff Spaulding, STS-133 NASA Test Director Steve Payne, Launch Orbiter Test Conductor John Kracsun and Assistant Launch Orbiter Test Conductor Mark Taffet. During today's tanking test, the team is paying particular attention to the external tank's ribbed intertank region. Beginning tomorrow, engineers will evaluate data on 21-foot-long, U-shaped aluminum brackets, called stringers, and the newly replaced ground umbilical carrier plate (GUCP). Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at the GUCP. In order to perform additional analysis on the tank, Discovery will be rolled back to the Vehicle Assembly Building, a move that is planned for next week. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Cory Huston

In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

DOEpatents

Taylor, Robert T.; Jackson, Kenneth J.; Duba, Alfred G.; Chen, Ching-I

1998-01-01

An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating.

In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

DOEpatents

Taylor, R.T.; Jackson, K.J.; Duba, A.G.; Chen, C.I.

1998-05-19

An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs.

10 CFR 32.59 - Same: Leak testing of each source.

Code of Federal Regulations, 2012 CFR

2012-01-01

... kilobecquerels (0.1 microcurie) of americium-241 or radium-226 before transferring the source to a general....185 kilobecquerel (0.005 microcurie) of americium-241 or radium-226. If this test discloses more than... leaking or losing americium-241 or radium-226 and shall not be transferred to a general licensee under...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swain, M.R.

The following report is divided into two sections. The first section describes the results of ignitability tests of high pressure hydrogen and natural gas leaks. The volume of ignitable gases formed by leaking hydrogen or natural gas were measured. Leaking high pressure hydrogen produced a cone of ignitable gases with 28{degrees} included angle. Leaking high pressure methane produced a cone of ignitable gases with 20{degrees} included angle. Ignition of hydrogen produced larger overpressures than did natural gas. The largest overpressures produced by hydrogen were the same as overpressures produced by inflating a 11 inch child`s balloon until it burst.

40 CFR Appendix L to Part 50 - Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere

Code of Federal Regulations, 2014 CFR

2014-07-01

... or an alternative external leak test technique may be required for samplers whose design or... alternative internal, filter bypass leak test technique may be required for samplers whose design or... variation or better has been established for the operational precision of PM2.5 monitoring data. 5.1 Tests...

40 CFR Appendix L to Part 50 - Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere

Code of Federal Regulations, 2012 CFR

2012-07-01

... or an alternative external leak test technique may be required for samplers whose design or... alternative internal, filter bypass leak test technique may be required for samplers whose design or... variation or better has been established for the operational precision of PM2.5 monitoring data. 5.1 Tests...

40 CFR Appendix L to Part 50 - Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere

Code of Federal Regulations, 2013 CFR

2013-07-01

... or an alternative external leak test technique may be required for samplers whose design or... alternative internal, filter bypass leak test technique may be required for samplers whose design or... variation or better has been established for the operational precision of PM2.5 monitoring data. 5.1 Tests...

Experimental testing of a foam/multilayer insulation (FMLI) thermal control system (TCS) for use on a cryogenic upper stage

NASA Astrophysics Data System (ADS)

Hastings, Leon J.; Martin, James J.

1998-01-01

An 18-m3 system-level test bed termed the Multipurpose Hydrogen Test Bed (MHTB has been used to evaluate a foam/multilayer combination insulation concept. The foam element (Isofoam SS-1171) protects against ground hold/ascent flight environments, and allows the use of dry nitrogen purge as opposed to a more complex/heavy helium purge subsystem. The MLI (45 layers of Double Aluminized Mylar with Dacron spacers) is designed for an on-orbit storage period of 45 days. Unique MLI features included; a variable layer density (reduces weight and radiation losses), larger but fewer DAM vent perforations (reduces radiation losses), and a roll wrap installation which resulted in a very robust MLI and reduced both assembly man-hours and seam heat leak. Ground hold testing resulted in an average heat leak of 63 W/m2 and purge gas liquefaction was successfully prevented. The orbit hold simulation produced a heat leak of 0.22 W/m2 with 305 K boundary which, compared to historical data, represents a 50-percent heat leak reduction.

Implementation of Leak Test Methods for the International Space Station (ISS) Elements, Systems and Components

NASA Technical Reports Server (NTRS)

Underwood, Steve; Lvovsky, Oleg

2007-01-01

The International Space Station (ISS has Qualification and Acceptance Environmental Test Requirements document, SSP 41172 that includes many environmental tests such as Thermal vacuum & Cycling, Depress/Repress, Sinusoidal, Random, and Acoustic Vibration, Pyro Shock, Acceleration, Humidity, Pressure, Electromatic Interference (EMI)/Electromagnetic Compatibility (EMCO), etc. This document also includes (13) leak test methods for Pressure Integrity Verification of the ISS Elements, Systems, and Components. These leak test methods are well known, however, the test procedure for specific leak test method shall be written and implemented paying attention to the important procedural steps/details that, if omitted or deviated, could impact the quality of the final product and affect the crew safety. Such procedural steps/details for different methods include, but not limited to: - Sequence of testing, f or example, pressurization and submersion steps for Method I (Immersion); - Stabilization of the mass spectrometer leak detector outputs fo r Method II (vacuum Chamber or Bell jar); - Proper data processing an d taking a conservative approach while making predictions for on-orbit leakage rate for Method III(Pressure Change); - Proper Calibration o f the mass spectrometer leak detector for all the tracer gas (mostly Helium) Methods such as Method V (Detector Probe), Method VI (Hood), Method VII (Tracer Probe), Method VIII(Accumulation); - Usage of visibl ility aides for Method I (Immersion), Method IV (Chemical Indicator), Method XII (Foam/Liquid Application), and Method XIII (Hydrostatic/Visual Inspection); While some methods could be used for the total leaka ge (either internal-to-external or external-to-internal) rate requirement verification (Vacuum Chamber, Pressure Decay, Hood, Accumulation), other methods shall be used only as a pass/fail test for individual joints (e.g., welds, fittings, and plugs) or for troubleshooting purposes (Chemical Indicator, Detector Probe, Tracer Probe, Local Vacuum Chamber, Foam/Liquid Application, and Hydrostatic/Visual Inspection). Any isolation of SSP 41172 requirements have led to either retesting of hardware or accepting a risk associated with the potential system or component pressure integrity problem during flight.

The mechanical and microbiological integrity of surgical gloves.

PubMed

Jamal, Ala; Wilkinson, Stephen

2003-03-01

Several manufacturers supply surgical gloves that have been individually tested (IT) for leaks. Other manufacturers supply gloves in which sample gloves from each batch are tested for leaks (batch tested: BT). The latter brands may be rejected by surgeons because of presumed increased risk of wound infection and staff exposure to patient pathogens. The influence of differences between glove brands on performance in surgery has not been extensively studied. The aims of the present study were to test the mechanical and microbiological integrity of IT compared to BT gloves. A total of 110 unused gloves from each of an IT and a BT brand were tested for leaks, first, by observation of water-jets from water-filled gloves and second, by measuring electrical resistance between inside and outside the glove surfaces, to give a baseline measure. A total of 304 IT and 280 BT gloves were then similarly leak-tested after 98 clean surgical procedures. The hands and gloves of scrub team members were cultured postsurgery. A total of 1/110 BT and 0/110 IT unused gloves contained leaks (NS, Fisher's exact test). Operative perforation rates were lower for BT compared with IT (8/280 cf. 22/304; P < 0.05 Fisher's exact test). There was no bias in types of operations or scrub team members to account for the difference. Growth of normal skin flora was found on virtually every wearer's hands post-operatively. Similar bacteria were frequently cultured from the outside of gloves at the conclusion of surgery (111/152 pairs IT cf. 122/140 pairs BT; P < 0.01, Fisher's exact test). This study provides evidence that the clinical performance of BT gloves is no different to IT gloves. There was no significant difference in mechanical leak rates for unused gloves. Paradoxically, although IT gloves were more likely to show macro-perforations after surgery, the incidence of contamination on the surface of BT gloves was greater, possibly reflecting a qualitative difference in glove material. This study suggests that both types of gloves develop microporosity during use, which may allow transfer of bacteria from the surgeon's skin to the surface of the glove.

High-Voltage Leak Detection of a Parenteral Proteinaceous Solution Product Packaged in Form-Fill-Seal Plastic Laminate Bags. Part 3. Chemical Stability and Visual Appearance of a Protein-Based Aqueous Solution for Injection as a Function of HVLD Exposure.

PubMed

Rasmussen, Mats; Damgaard, Rasmus; Buus, Peter; Guazzo, Dana Morton

2013-01-01

This Part 3 of this three-part research series reports the impact of high-voltage leak detection (HVLD) exposure on the physico-chemical stability of the packaged product. The product, intended for human administration by injection, is an aqueous solution formulation of the rapid acting insulin analogue, insulin aspart (NovoRapid®/NovoLog®) by Novo Nordisk A/S, Bagsværd, Denmark. The package is a small-volume form-fill-seal plastic laminate bag. Product-packages exposed to HVLD were compared to unexposed product after storage for 9 months at recommended storage conditions of 5 ± 3 °C. No differences in active ingredient or degradation products assays were noted. No changes in any other stability indicating parameter results were observed. This report concludes this three-part series. Part 1 documented HVLD method development and validation work. Part 2 explored the impact of various package material, package temperature, and package storage conditions on HVLD test results. Detection of leaks in the bag seal area was investigated. In conclusion, HVLD is reported to be a validatable leak test method suitable for rapid, nondestructive container-closure integrity evaluation of the subject product-package. In Part 1 of this three-part series, a leak test method based on electrical conductivity and capacitance, also called high-voltage leak detection (HVLD), was proven to find hole leaks in small plastic bags filled with a solution of insulin aspart intended for human injection (NovoRapid®/NovoLog® by Novo Nordisk A/S, Bagsværd, Denmark). In Part 2, the ability of the HVLD method to find other types of package leaks was tested, and the impact of package material and product storage temperature on HVLD results was explored. This final Part 3 checked how well the packaged protein drug solution maintained its potency after HVLD exposure over 9 months of storage under long-term stability conditions. Results showed that HVLD caused no harm to the product.

DETECTION OF COATING FAILURES IN A NEUTRONIC REACTOR

DOEpatents

Snell, A.H.; Allison, S.K.

1958-02-11

This patent relates to water-cooled reactor systems and discloses a means to detect leaks in the jackets of jacketed fuel elements comprising a neutron detector located in the cooling water discharge pipe,the pipe being provided with an enlarged portion for housing the detector so that the latter is completely surrounded by the water in its passage through the pipe, said enlarged portion and detector being shielded from the reactor for the purpose of detecting only those delayed neutrons emitted in the cooling water and due to the latter picking up fission fragments from the defective fuel elements.

Overview of technologies for removal of methyl tert-butyl ether (MTBE) from water.

PubMed

Levchuk, Irina; Bhatnagar, Amit; Sillanpää, Mika

2014-04-01

Wide use of methyl tert-butyl ether (MTBE) as fuel oxygenates leads to worldwide environment contamination with this compound basically due to fuel leaks from storage or pipelines. Presence of MTBE in drinking water is of high environmental and social concern. Existing methods for MTBE removal from water have a number of limitations which can be possibly overcome in the future with use of emerging technologies. This work aims to provide an updated overview of recent developments in technologies for MTBE removal from water. Copyright © 2014. Published by Elsevier B.V.

Structural aspects of coaxial oxy-fuel flames

NASA Astrophysics Data System (ADS)

Ditaranto, M.; Sautet, J. C.; Samaniego, J. M.

Oxy-fuel combustion has been proven to increase thermal efficiency and to have a potential for NOx emission reduction. The study of 25-kW turbulent diffusion flames of natural gas with pure oxygen is undertaken on a coaxial burner with quarl. The structural properties are analysed by imaging the instantaneous reaction zone by OH* chemiluminescence and measuring scalar and velocity profiles. The interaction between the flame front and the shear layers present in the coaxial jets depends on the momentum ratio which dictates the turbulent structure development. Flame length and NOx emission sensitivity to air leaks in the combustion chamber are also investigated.

KSC-06pd0209

NASA Image and Video Library

2006-02-07

KENNEDY SPACE CENTER, FLA. - Before dawn, the Virgin Atlantic GlobalFlyer is being fueled on NASA Kennedy Space Center’s Shuttle Landing Facility (SLF). Steve Fossett will pilot the GlobalFlyer on a record-breaking attempt by flying solo, non-stop without refueling, to surpass the current record for the longest flight of any aircraft. Fossett is expected to take off from the KSC SLF. Later, takeoff of the GlobalFlyer was postponed due to a fuel leak that appeared during the last moments of loading. The next planned takeoff attempt is 7 a.m. Feb. 8 from the SLF. Photo credit: NASA/Kim Shiflett

Study to develop improved methods to detect leakage in fluid systems, phase 2

NASA Technical Reports Server (NTRS)

Janus, J. C.; Cimerman, I.

1971-01-01

An ultrasonic contact sensor engineering prototype leak detection system was developed and its capabilities under cryogenic operations demonstrated. The results from tests indicate that the transducer performed well on liquid hydrogen plumbing, that flow and valve actuation could be monitored, and that the phase change from gaseous to liquid hydrogen could be detected by the externally mounted transducers. Tests also demonstrate the ability of the system to detect internal leaks past valve seats and to function as a flow meter. Such a system demonstrates that it is not necessary to break into welded systems to locate internal leaks.

Comparison of the safety-related physical and combustion properties of liquid hydrogen and liquid natural gas in the context of the SF-BREEZE high-speed fuel-cell ferry

DOE PAGES

Klebanoff, L. E.; Pratt, J. W.; LaFleur, C. B.

2016-11-25

Here, we review liquid hydrogen (LH 2) as a maritime vessel fuel, from descriptions of its fundamental properties to its practical application and safety aspects, in the context of the San Francisco Bay Renewable Energy Electric Vessel with Zero Emissions (SF-BREEZE) high-speed fuel-cell ferry. Since marine regulations have been formulated to cover liquid natural gas (LNG) as a primary propulsion fuel, we frame our examination of LH 2 as a comparison to LNG, for both maritime use in general, and the SF-BREEZE in particular. Due to weaker attractions between molecules, LH 2 is colder than LNG, and evaporates more easily.more » We describe the consequences of these physical differences for the size and duration of spills of the two cryogenic fuels. The classical flammability ranges are reviewed, with a focus on how fuel buoyancy modifies these combustion limits. We examine the conditions for direct fuel explosion (detonation) and contrast them with initiation of normal (laminar) combustion. Direct fuel detonation is not a credible accident scenario for the SF-BREEZE. For both fuels, we review experiments and theory elucidating the deflagration to detonation transition (DDT). LH 2 fires have a shorter duration than energy-equivalent LNG fires, and produce significantly less thermal radiation. The thermal (infrared) radiation from hydrogen fires is also strongly absorbed by humidity in the air. Hydrogen permeability is not a leak issue for practical hydrogen plumbing. We describe the chemistry of hydrogen and methane at iron surfaces, clarifying their impact on steel-based hydrogen storage and transport materials. These physical, chemical and combustion properties are pulled together in a comparison of how a LH 2 or LNG pool fire on the Top Deck of the SF-BREEZE might influence the structural integrity of the aluminum deck. Neither pool fire scenario leads to net heating of the aluminum decking. Overall, LH 2 and LNG are very similar in their physical and combustion properties, thereby posing similar safety risks. For ships utilizing LH 2 or LNG, precautions are needed to avoid fuel leaks, minimize ignition sources, minimize confined spaces, provide ample ventilation for required confined spaces, and to monitor the enclosed spaces to ensure any fuel accumulation is detected far below the fuel/air mix threshold for any type of combustion.« less

Comparison of the safety-related physical and combustion properties of liquid hydrogen and liquid natural gas in the context of the SF-BREEZE high-speed fuel-cell ferry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klebanoff, L. E.; Pratt, J. W.; LaFleur, C. B.

Here, we review liquid hydrogen (LH 2) as a maritime vessel fuel, from descriptions of its fundamental properties to its practical application and safety aspects, in the context of the San Francisco Bay Renewable Energy Electric Vessel with Zero Emissions (SF-BREEZE) high-speed fuel-cell ferry. Since marine regulations have been formulated to cover liquid natural gas (LNG) as a primary propulsion fuel, we frame our examination of LH 2 as a comparison to LNG, for both maritime use in general, and the SF-BREEZE in particular. Due to weaker attractions between molecules, LH 2 is colder than LNG, and evaporates more easily.more » We describe the consequences of these physical differences for the size and duration of spills of the two cryogenic fuels. The classical flammability ranges are reviewed, with a focus on how fuel buoyancy modifies these combustion limits. We examine the conditions for direct fuel explosion (detonation) and contrast them with initiation of normal (laminar) combustion. Direct fuel detonation is not a credible accident scenario for the SF-BREEZE. For both fuels, we review experiments and theory elucidating the deflagration to detonation transition (DDT). LH 2 fires have a shorter duration than energy-equivalent LNG fires, and produce significantly less thermal radiation. The thermal (infrared) radiation from hydrogen fires is also strongly absorbed by humidity in the air. Hydrogen permeability is not a leak issue for practical hydrogen plumbing. We describe the chemistry of hydrogen and methane at iron surfaces, clarifying their impact on steel-based hydrogen storage and transport materials. These physical, chemical and combustion properties are pulled together in a comparison of how a LH 2 or LNG pool fire on the Top Deck of the SF-BREEZE might influence the structural integrity of the aluminum deck. Neither pool fire scenario leads to net heating of the aluminum decking. Overall, LH 2 and LNG are very similar in their physical and combustion properties, thereby posing similar safety risks. For ships utilizing LH 2 or LNG, precautions are needed to avoid fuel leaks, minimize ignition sources, minimize confined spaces, provide ample ventilation for required confined spaces, and to monitor the enclosed spaces to ensure any fuel accumulation is detected far below the fuel/air mix threshold for any type of combustion.« less

Standard Test Procedures for Evaluating Various Leak Detection Methods

EPA Pesticide Factsheets

Learn about protocols that testers could use to demonstrate that an individual release detection equipment type could meet the performance requirements noted in the federal UST requirements for detecting leaks.

Development of a low cost unmanned aircraft system for atmospheric carbon dioxide leak detection

NASA Astrophysics Data System (ADS)

Mitchell, Taylor Austin

Carbon sequestration, the storage of carbon dioxide gas underground, has the potential to reduce global warming by removing a greenhouse gas from the atmosphere. These storage sites, however, must first be monitored to detect if carbon dioxide is leaking back out to the atmosphere. As an alternative to traditional large ground-based sensor networks to monitor CO2 levels for leaks, unmanned aircraft offer the potential to perform in-situ atmospheric leak detection over large areas for a fraction of the cost. This project developed a proof-of-concept sensor system to map relative carbon dioxide levels to detect potential leaks. The sensor system included a Sensair K-30 FR CO2 sensor, GPS, and altimeter connected an Arduino microcontroller which logged data to an onboard SD card. Ground tests were performed to verify and calibrate the system including wind tunnel tests to determine the optimal configuration of the system for the quickest response time (4-8 seconds based upon flowrate). Tests were then conducted over a controlled release of CO 2 in addition to over controlled rangeland fires which released carbon dioxide over a large area as would be expected from a carbon sequestration source. 3D maps of carbon dioxide were developed from the system telemetry that clearly illustrated increased CO2 levels from the fires. These tests demonstrated the system's ability to detect increased carbon dioxide concentrations in the atmosphere.

Polyethylene glycol hydrogel polymer sealant for vitrectomy surgery: an in vitro study of sutureless vitrectomy incision closure.

PubMed

Hariprasad, Seenu M; Singh, Ajay

2011-03-01

To test a novel hydrogel sealant to secure sutureless sclerotomies under variable intraocular pressure conditions. In cadaver eyes, 23- and 20-gauge (G) sclerotomies were constructed. Sixteen 23-G beveled sclerotomies were constructed in 4 eyes: 8 of the incisions were treated with hydrogel sealant, while 8 were left bare. All sclerotomies were monitored for leaks while the intraocular pressure was elevated. The pressure on incision leakage was recorded as the leak pressure (maximum tested = 140 mm Hg). Additionally, sixteen 20-G sclerotomies were constructed in 4 other eyes: 8 of the incisions were treated with hydrogel sealant, while 8 were sutured. These incisions were similarly pressure tested. Among the 23-G incisions, hydrogel sealant application to the incisions significantly increased the leak pressure relative to bare incisions: mean (SE), 131.8 (8.2) vs 39.5 (5.2) mm Hg, respectively (P < .001). Only 1 of the 8 sealant-treated 23-G incisions leaked below 140 mm Hg, compared with all of the 8 bare incisions. Among the 20-G incisions, there was no difference in leak pressure among sealant-treated and sutured incisions: mean (SE), 140.0 (0.0) vs 136.3 (3.8) mm Hg, respectively (P = .35). None of the 8 sealant-treated 20-G incisions leaked below 140 mm Hg, compared with 1 of the 8 sutured incisions. Hydrogel sealant significantly increased the leak pressure among 23-G incisions relative to 23-G bare incisions and was equivalent to suturing among 20-G incisions. Hydrogel sealants effectively close vitrectomy incisions and may decrease the incidence of postoperative endophthalmitis and hypotony.

Identification of multiple leaks in pipeline: Linearized model, maximum likelihood, and super-resolution localization

NASA Astrophysics Data System (ADS)

Wang, Xun; Ghidaoui, Mohamed S.

2018-07-01

This paper considers the problem of identifying multiple leaks in a water-filled pipeline based on inverse transient wave theory. The analytical solution to this problem involves nonlinear interaction terms between the various leaks. This paper shows analytically and numerically that these nonlinear terms are of the order of the leak sizes to the power two and; thus, negligible. As a result of this simplification, a maximum likelihood (ML) scheme that identifies leak locations and leak sizes separately is formulated and tested. It is found that the ML estimation scheme is highly efficient and robust with respect to noise. In addition, the ML method is a super-resolution leak localization scheme because its resolvable leak distance (approximately 0.15λmin , where λmin is the minimum wavelength) is below the Nyquist-Shannon sampling theorem limit (0.5λmin). Moreover, the Cramér-Rao lower bound (CRLB) is derived and used to show the efficiency of the ML scheme estimates. The variance of the ML estimator approximates the CRLB proving that the ML scheme belongs to class of best unbiased estimator of leak localization methods.

Helium Mass Spectrometer Leak Detection: A Method to Quantify Total Measurement Uncertainty

NASA Technical Reports Server (NTRS)

Mather, Janice L.; Taylor, Shawn C.

2015-01-01

In applications where leak rates of components or systems are evaluated against a leak rate requirement, the uncertainty of the measured leak rate must be included in the reported result. However, in the helium mass spectrometer leak detection method, the sensitivity, or resolution, of the instrument is often the only component of the total measurement uncertainty noted when reporting results. To address this shortfall, a measurement uncertainty analysis method was developed that includes the leak detector unit's resolution, repeatability, hysteresis, and drift, along with the uncertainty associated with the calibration standard. In a step-wise process, the method identifies the bias and precision components of the calibration standard, the measurement correction factor (K-factor), and the leak detector unit. Together these individual contributions to error are combined and the total measurement uncertainty is determined using the root-sum-square method. It was found that the precision component contributes more to the total uncertainty than the bias component, but the bias component is not insignificant. For helium mass spectrometer leak rate tests where unit sensitivity alone is not enough, a thorough evaluation of the measurement uncertainty such as the one presented herein should be performed and reported along with the leak rate value.

Noble Gas Leak Detector for Use in the SNS Neutron Electric Dipole Moment Experiment

NASA Astrophysics Data System (ADS)

Barrow, Chad; Huffman, Paul; Leung, Kent; Korobkina, Ekaterina; White, Christian; nEDM Collaboration Collaboration

2017-09-01

Common practice for leak-checking high vacuum systems uses helium as the probing gas. However, helium may permeate some materials at room temperature, making leak characterization difficult. The experiment to find a permanent electric dipole moment of the neutron (nEDM), to be conducted at Oak Ridge National Laboratories, will employ a large volume of liquid helium housed by such a helium-permeable composite material. It is desirable to construct a leak detector that can employ alternative test gases. The purpose of this experiment is to create a leak detector that can quantify the argon gas flux in a high vacuum environment and interpret this flux as a leak-rate. This apparatus will be used to check the nEDM volumes for leaks at room temperature before cooling down to cryogenic temperatures. Our leak detector uses a residual gas analyzer and a vacuum pumping station to characterize the gas present in an evacuated volume. The introduction of argon gas into the system is interpreted as a leak-rate into the volume. The device has been calibrated with NIST certified calibrated leaks and the machine's sensitivity has been calculated using background gas analysis. As a result of the device construction and software programming, we are able to leak-check composite and polyamide volumes This work was supported in part by the US Department of Energy under Grant No. DE-FG02-97ER41042.

Quantitative study of sniffer leak rate and pressure drop leak rate of liquid nitrogen panels of SST-1 tokamak

NASA Astrophysics Data System (ADS)

Pathan, F. S.; Khan, Z.; Semwal, P.; Raval, D. C.; Joshi, K. S.; Thankey, P. L.; Dhanani, K. R.

2008-05-01

Steady State Super-conducting (SST-1) Tokamak is in commissioning stage at Institute for Plasma Research. Vacuum chamber of SST-1 Tokamak consists of 1) Vacuum vessel, an ultra high vacuum (UHV) chamber, 2) Cryostat, a high vacuum (HV) chamber. Cryostat encloses the liquid helium cooled super-conducting magnets (TF and PF), which require the thermal radiation protection against room temperature. Liquid nitrogen (LN2) cooled panels are used to provide thermal shield around super-conducting magnets. During operation, LN2 panels will be under pressurized condition and its surrounding (cryostat) will be at high vacuum. Hence, LN2 panels must have very low leak rate. This paper describes an experiment to study the behaviour of the leaks in LN2 panels during sniffer test and pressure drop test using helium gas.

Elastomeric Seal Performance after Terrestrial Ultraviolet Radiation Exposure

NASA Technical Reports Server (NTRS)

Daniels, Christopher C.; Oravec, Heather A.; Mather, Janice L.; Taylor, Shawn C.; Dunlap, Patrick H.

2015-01-01

Ultraviolet radiation was evaluated to determine its negative effects on the performance of elastomeric gas pressure seals. The leak rates of the silicone elastomer S0383-70 O-ring test articles were used to quantify the degradation of the seals after exposure to vacuum-ultraviolet and/or middle-to-near-ultraviolet wavelength radiation. Three groups of seals were exposed in terrestrial facilities to 115-165 nm wavelength radiation, 230-500 nm wavelength radiation, or both spectrums, for an orbital spaceflight equivalent of 125 hours. The leak rates of the silicone elastomer S0383-70 seals were quantified and compared to samples that received no radiation. Each lot contained six samples and statistical t-tests were used to determine the separate and combined influences of exposure to the two wavelength ranges. A comparison of the mean leak rates of samples exposed to 115-165 nm wavelength radiation to the control specimens showed no difference, suggesting that spectrum was not damaging. The 230-500 nm wavelength appeared to be damaging, as the mean leak rates of the specimens exposed to that range of wavelengths, and those exposed to the combined 115-165 nm and 230-500 nm spectrums, were significantly different from the leak rates of the control specimens. Most importantly, the test articles exposed to both wavelength spectrums exhibited mean leak rates two orders of magnitude larger than any other exposed specimens, which suggested that both wavelength spectrums are important when simulating the orbital environment.

Two-stream Convolutional Neural Network for Methane Emissions Quantification

NASA Astrophysics Data System (ADS)

Wang, J.; Ravikumar, A. P.; McGuire, M.; Bell, C.; Tchapmi, L. P.; Brandt, A. R.

2017-12-01

Methane, a key component of natural gas, has a 25x higher global warming potential than carbon dioxide on a 100-year basis. Accurately monitoring and mitigating methane emissions require cost-effective detection and quantification technologies. Optical gas imaging, one of the most commonly used leak detection technology, adopted by Environmental Protection Agency, cannot estimate leak-sizes. In this work, we harness advances in computer science to allow for rapid and automatic leak quantification. Particularly, we utilize two-stream deep Convolutional Networks (ConvNets) to estimate leak-size by capturing complementary spatial information from still plume frames, and temporal information from plume motion between frames. We build large leak datasets for training and evaluating purposes by collecting about 20 videos (i.e. 397,400 frames) of leaks. The videos were recorded at six distances from the source, covering 10 -60 ft. Leak sources included natural gas well-heads, separators, and tanks. All frames were labeled with a true leak size, which has eight levels ranging from 0 to 140 MCFH. Preliminary analysis shows that two-stream ConvNets provides significant accuracy advantage over single steam ConvNets. Spatial stream ConvNet can achieve an accuracy of 65.2%, by extracting important features, including texture, plume area, and pattern. Temporal stream, fed by the results of optical flow analysis, results in an accuracy of 58.3%. The integration of the two-stream ConvNets gives a combined accuracy of 77.6%. For future work, we will split the training and testing datasets in distinct ways in order to test the generalization of the algorithm for different leak sources. Several analytic metrics, including confusion matrix and visualization of key features, will be used to understand accuracy rates and occurrences of false positives. The quantification algorithm can help to find and fix super-emitters, and improve the cost-effectiveness of leak detection and repair programs.

EIGHTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W. L.

2013-09-03

A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23more » GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 61 - 85 months, which is still bounding to O-ring temperatures during storage in KArea Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leaktight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 41 - 45 months. Aging and periodic leak testing will continue for the remaining PCV fixtures.« less

LEAKAGE TESTING METHOD

DOEpatents

McAdams, Wm.A.; Foss, M.H.

1958-08-12

A method of testing containers for leaks is described, particularly the testing of containers or cans in which the uranium slugs for nuelear reactors are jacketed. This method involves the immersion of the can in water under l50 pounds of pressure, then removing, drying, and coating the can with anhydrous copper sulfate. Amy water absorbed by the can under pressure will exude and discolor the copper sulfate in the area about the leak.

Space Station Freedom seal leakage rate analysis and testing summary: Air leaks in ambient versus vacuum exit conditions

NASA Technical Reports Server (NTRS)

Rodriguez, P. I.; Markovitch, R.

1992-01-01

This report is intended to reveal the apparent relationship of air seal leakage rates between 2 atmospheres (atm) to 1 atm and 1 atm to vacuum conditions. Gas dynamics analysis is provided as well as data summarizing the MSFC test report, 'Space Station Freedom (S.S. Freedom) Seal Flaw Study With Delta Pressure Leak Rate Comparison Test Report'.

LEAK AND GAS PERMEABILITY TESTING DURING SOIL-GAS SAMPLING AT HAL'S CHEVRON LUST SITE IN GREEN RIVER, UTAH

EPA Science Inventory

The results of gas permeability and leak testing during active soil-gas sampling at Hal’s Chevron LUST Site in Green River, Utah are presented. This study was conducted to support development of a passive soil-gas sampling method. Gas mixtures containing helium and methane were...

Weld leaks rapidly and safely detected

NASA Technical Reports Server (NTRS)

1965-01-01

Test method detects leaks that occur during hydrostatic pressure testing of welded joints in metal tanks. A strip of aluminum foil and a strip of water-soluble paper are placed over the weld. A voltage applied between the tank wall and the foil strip is monitored to detect a decrease in ohmic resistance caused by water leakage into the paper layer.

40 CFR 60.482-2a - Standards: Pumps in light liquid service.

Code of Federal Regulations, 2011 CFR

2011-07-01

... routed to a process or fuel gas system or connected by a closed vent system to a control device that... sensor that will detect failure of the seal system, the barrier fluid system, or both. (4)(i) Each pump... indications of liquids dripping as a leak. (5)(i) Each sensor as described in paragraph (d)(3) is checked...

Solid oxidized fuel cells seals leakage setup and testing

NASA Technical Reports Server (NTRS)

Bastrzyk, Marta B.

2004-01-01

As the world s reserves of fossil fuels are depleted, the U.S. Government, as well as other countries and private industries, is researching solutions for obtaining power, answers that would be more efficient and environmentally friendly. For a long time engineers have been trying to obtain the benefits of clean electric power without heavy batteries or pollution-producing engines. While some of the inventions proved to be effective (i.e. solar panels or windmills) their applications are limited due to dependency on the energy source (i.e. sun or wind). Currently, as energy concerns increase, research is being carried out on the development of a Solid Oxide Fuel Cell (SOFC). The United States government is taking a proactive role in expanding the technology through the Solid State Energy Conversion Alliance (SECA) Program, which is coordinated by the Department of Energy. into an electrical energy. This occurs by the means of natural tendency of oxygen and hydrogen to chemically react. While controlling the process, it is possible to harvest the energy given off by the reaction. SOFCs use currently available fossil fuels and convert a variety of those fuels with very high efficiency (about 40% more efficient than modem thermal power plants). At the same time they are almost entirely nonpolluting and due to their size they can be placed in remote areas. The main fields where the application of the fuel cells appears to be the most useful for are stationary energy sources, transportation, and military applications. structure and materials must be resolved. All the components must be operational in harsh environments including temperatures reaching 800 C and cyclic thermal- mechanical loading. Under these conditions, the main concern is the requirement for hermetic seals to: (1) prevent mixing of the fuel and oxidant within the stack, (2) prevent parasitic leakage of the fuel from the stack, (3) prevent contamination of the anode by air leaking into the stack, (4) electrically isolate the individual cells within the stack, and (5) mechanically bond the cell components. The sealing challenges are aggravated by the need to maintain hermetic boundaries between the different flow paths within the fuel cell throughout cycled operation. Within the timeframe of my tenure, the main objective is to assist in building a state-of-art test facility.

KSC-2010-5885

NASA Image and Video Library

2010-12-17

CAPE CANAVERAL, Fla. -- Team members stationed at consoles in the Launch Control Center at NASA's Kennedy Space Center in Florida monitor space shuttle Discovery's external fuel tank as it is loaded with more than 535,000 gallons of cryogenic propellants. From back, are STS-133 Assistant NASA Test Director Jeff Spaulding, STS-133 NASA Test Director Steve Payne and Launch Orbiter Test Conductor John Kracsun. During today's tanking test, the team is paying particular attention to the external tank's ribbed intertank region. Beginning tomorrow, engineers will evaluate data on 21-foot-long, U-shaped aluminum brackets, called stringers, and the newly replaced ground umbilical carrier plate (GUCP). Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at the GUCP. In order to perform additional analysis on the tank, Discovery will be rolled back to the Vehicle Assembly Building, a move that is planned for next week. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Cory Huston

KSC-2010-5881

NASA Image and Video Library

2010-12-17

CAPE CANAVERAL, Fla. -- Team members stationed at consoles in the Launch Control Center at NASA's Kennedy Space Center in Florida monitor space shuttle Discovery's external fuel tank as it is loaded with more than 535,000 gallons of cryogenic propellants. From left, are STS-133 Assistant NASA Test Director Jeff Spaulding, NASA Test Director Jeremy Graeber and STS-133 NASA Test Director Steve Payne. During today's tanking test, the team is paying particular attention to the external tank's ribbed intertank region. Beginning tomorrow, engineers will evaluate data on 21-foot-long, U-shaped aluminum brackets, called stringers, and the newly replaced ground umbilical carrier plate (GUCP). Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at the GUCP. In order to perform additional analysis on the tank, Discovery will be rolled back to the Vehicle Assembly Building, a move that is planned for next week. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Cory Huston

Performance of Leak Compensation in All-Age ICU Ventilators During Volume-Targeted Neonatal Ventilation: A Lung Model Study.

PubMed

Itagaki, Taiga; Bennett, Desmond J; Chenelle, Christopher T; Fisher, Daniel F; Kacmarek, Robert M

2017-01-01

Volume-targeted ventilation is increasingly used in low birthweight infants because of the potential for reducing volutrauma and avoiding hypocapnea. However, it is not known what level of air leak is acceptable during neonatal volume-targeted ventilation when leak compensation is activated concurrently. Four ICU ventilators (Servo-i, PB980, V500, and Avea) were compared in available invasive volume-targeted ventilation modes (pressure control continuous spontaneous ventilation [PC-CSV] and pressure control continuous mandatory ventilation [PC-CMV]). The Servo-i and PB980 were tested with (+) and without (-) their proximal flow sensor. The V500 and Avea were tested with their proximal flow sensor as indicated by their manufacturers. An ASL 5000 lung model was used to simulate 4 neonatal scenarios (body weight 0.5, 1, 2, and 4 kg). The ASL 5000 was ventilated via an endotracheal tube with 3 different leaks. Two minutes of data were collected after each change in leak level, and the asynchrony index was calculated. Tidal volume (V T ) before and after the change in leak was assessed. The differences in delivered V T between before and after the change in leak were within ±5% in all scenarios with the PB980 (-/+) and V500. With the Servo-i (-/+), baseline V T was ≥10% greater than set V T during PC-CSV, and delivered V T markedly changed with leak. The Avea demonstrated persistent high V T in all leak scenarios. Across all ventilators, the median asynchrony index was 1% (interquartile range 0-27%) in PC-CSV and 1.8% (0-45%) in PC-CMV. The median asynchrony index was significantly higher in the Servo-i (-/+) than in the PB980 (-/+) and V500 in 1 and 2 kg scenarios during PC-CSV and PC-CMV. The PB980 and V500 were the only ventilators to acclimate to all leak scenarios and achieve targeted V T . Further clinical investigation is needed to validate the use of leak compensation during neonatal volume-targeted ventilation. Copyright © 2017 by Daedalus Enterprises.

Electricity from methane by reversing methanogenesis

PubMed Central

McAnulty, Michael J.; G. Poosarla, Venkata; Kim, Kyoung-Yeol; Jasso-Chávez, Ricardo; Logan, Bruce E.; Wood, Thomas K.

2017-01-01

Given our vast methane reserves and the difficulty in transporting methane without substantial leaks, the conversion of methane directly into electricity would be beneficial. Microbial fuel cells harness electrical power from a wide variety of substrates through biological means; however, the greenhouse gas methane has not been used with much success previously as a substrate in microbial fuel cells to generate electrical current. Here we construct a synthetic consortium consisting of: (i) an engineered archaeal strain to produce methyl-coenzyme M reductase from unculturable anaerobic methanotrophs for capturing methane and secreting acetate; (ii) micro-organisms from methane-acclimated sludge (including Paracoccus denitrificans) to facilitate electron transfer by providing electron shuttles (confirmed by replacing the sludge with humic acids), and (iii) Geobacter sulfurreducens to produce electrons from acetate, to create a microbial fuel cell that converts methane directly into significant electrical current. Notably, this methane microbial fuel cell operates at high Coulombic efficiency. PMID:28513579

Electricity from methane by reversing methanogenesis

NASA Astrophysics Data System (ADS)

McAnulty, Michael J.; G. Poosarla, Venkata; Kim, Kyoung-Yeol; Jasso-Chávez, Ricardo; Logan, Bruce E.; Wood, Thomas K.

2017-05-01

Given our vast methane reserves and the difficulty in transporting methane without substantial leaks, the conversion of methane directly into electricity would be beneficial. Microbial fuel cells harness electrical power from a wide variety of substrates through biological means; however, the greenhouse gas methane has not been used with much success previously as a substrate in microbial fuel cells to generate electrical current. Here we construct a synthetic consortium consisting of: (i) an engineered archaeal strain to produce methyl-coenzyme M reductase from unculturable anaerobic methanotrophs for capturing methane and secreting acetate; (ii) micro-organisms from methane-acclimated sludge (including Paracoccus denitrificans) to facilitate electron transfer by providing electron shuttles (confirmed by replacing the sludge with humic acids), and (iii) Geobacter sulfurreducens to produce electrons from acetate, to create a microbial fuel cell that converts methane directly into significant electrical current. Notably, this methane microbial fuel cell operates at high Coulombic efficiency.

FY2017 status report: Model 9975 O-ring fixture long-term leak performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W. L.

A series of experiments to monitor the aging performance of Viton® GLT and GLT-S O-rings used in the Model 9975 shipping package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups with GLT O-rings were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially andmore » have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, a smaller test matrix with fourteen additional tests was initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. Leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The 300 °F GLT O-ring fixtures failed after 2.8 to 5.7 years at temperature. The remaining GLT O-ring fixtures aging at 300 ºF were retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 9 to 10.5 years, or in GLT O-ring fixtures aging at 270 ºF for 5.7 years. These aging temperatures bound O-ring temperatures anticipated during normal storage in K-Area Complex (KAC). Leak test failures have been experienced in all of the GLT-S O-ring fixtures aging at 300 ºF and above. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 and 250 ºF for 6.9 to 7.5 years. Data from the O-ring fixtures are generally consistent with results from compression stress relaxation testing, and provide confidence in the predictive models based on those results. However, uncertainty still exists in extrapolating these elevated temperature results to the lower temperatures of interest for normal storage in KAC. Measurement of compression set in O-rings removed from failed fixtures, compared to that from KAC surveillance O-rings, indicates margin remains for O-rings still in service. Aging and periodic leak testing will continue for the remaining PCV fixtures.« less

KSC-2010-5611

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker begins to remove the ground umbilical carrier plate's (GUCP) 7-inch quick disconnect. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5570

NASA Image and Video Library

2010-11-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to begin removing the quick disconnect from the ground umbilical carrier plate (GUCP) on space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for the STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is targeted for no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5608

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to remove the ground umbilical carrier plate's (GUCP) 7-inch quick disconnect. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5566

NASA Image and Video Library

2010-11-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to begin removing the quick disconnect from the ground umbilical carrier plate (GUCP) on space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for the STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is targeted for no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5565

NASA Image and Video Library

2010-11-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to begin removing the quick disconnect from the ground umbilical carrier plate (GUCP) on space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for the STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is targeted for no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5609

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a worker prepares to remove the ground umbilical carrier plate's (GUCP) 7-inch quick disconnect. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5634

NASA Image and Video Library

2010-11-11

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers examine one of the ground umbilical carrier plate's (GUCP) quick disconnects. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

KSC-2010-5567

NASA Image and Video Library

2010-11-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to begin removing the quick disconnect from the ground umbilical carrier plate (GUCP) on space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for the STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is targeted for no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5610

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers begin to remove the ground umbilical carrier plate's (GUCP) 7-inch quick disconnect. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5631

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers remove one of the ground umbilical carrier plate's (GUCP) quick disconnects. A hydrogen gas leak at that location on the external fuel tank during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the excess hydrogen is burned off. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Jack Pfaller

KSC-2010-5569

NASA Image and Video Library

2010-11-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to begin removing the quick disconnect from the ground umbilical carrier plate (GUCP) on space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for the STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is targeted for no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5614

NASA Image and Video Library

2010-11-10

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, the ground umbilical carrier plate's (GUCP) 7-inch quick disconnect has been removed from the external fuel tank. A hydrogen gas leak at that location during tanking for space shuttle Discovery's STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

KSC-2010-5568

NASA Image and Video Library

2010-11-09

CAPE CANAVERAL, Fla. -- On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers prepare to begin removing the quick disconnect from the ground umbilical carrier plate (GUCP) on space shuttle Discovery's external fuel tank. A hydrogen gas leak at that location during tanking for the STS-133 mission to the International Space Station caused the launch attempt to be scrubbed Nov. 5. The GUCP will be examined to determine the cause of the hydrogen leak and then repaired. The GUCP is the overboard vent to the pad and the flame stack where the vented hydrogen is burned off. Discovery's next launch attempt is targeted for no earlier than Nov. 30 at 4:02 a.m. EST. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Troy Cryder

NINTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W.

2014-08-06

A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperatures. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determinemore » if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The earliest 300 °F GLT O-ring fixture failure was observed at 34 months. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 72 - 96 months, which bounds O-ring temperatures anticipated during storage in K-Area Complex (KAC). Based on expectations that the 200 ºF fixtures will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures, thus providing additional time to failure data. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 54 - 57 months. No additional O-ring failures have been observed since the last interim report was issued. Aging and periodic leak testing will continue for the remaining PCV fixtures. Additional irradiation of several fixtures is recommended to maintain a balance between thermal and radiation exposures similar to that experienced in storage, and to show the degree of consistency of radiation response between GLT and GLT-S O-rings.« less

Residential releases of number 2 fuel oil: a contributor to indoor air pollution.

PubMed Central

Kaplan, M B; Brandt-Rauf, P; Axley, J W; Shen, T T; Sewell, G H

1993-01-01

OBJECTIVES. Analysis of data from the New York City Fire Department showed that residential fuel oil releases frequently occur in quantities ranging from 5 to 1000 gal, primarily from storage tank leaks and overfill. A risk assessment was conducted to determine whether Number 2 fuel oil basement spills pose a significant risk to human health. METHODS. Exposure was derived from a simulated field study spill of Number 2 fuel oil in a townhouse basement to develop emission rates for the indicator constituent xylene. Distribution of xylene throughout the townhouse was determined using a multizone contaminant dispersal model. RESULTS. Spills of 85 and 21 gal resulted in xylene exposure estimates as high as 20 and 5 mg/kg/day, respectively. CONCLUSIONS. A spill of about 21 gal or more of Number 2 fuel oil would present a human health risk for central nervous and reproductive systems for 8 days or longer. Tank inspection and supervised delivery would provide effective prevention at minimal expense. PMID:8417613

The usefulness and costs of routine contrast studies after laparoscopic sleeve gastrectomy for detecting staple line leaks

PubMed Central

Terterov, Dimitry; Leung, Philemon Ho-Yan; Twells, Laurie K.; Gregory, Deborah M.; Smith, Chris; Boone, Darrell; Pace, David

2017-01-01

Background Although laparoscopic sleeve gastrectomy (LSG) has been shown to be a safe and effective treatment for severe obesity (body mass index ≥ 35), staple line leaks remain a major complication and account for a substantial portion of the procedure’s morbidity and mortality. Many centres performing LSG routinely obtain contrast studies on postoperative day 1 for early detection of staple line leaks. We examined the usefulness of Gastrografin swallow as an early detection test for staple line leaks on postoperative day 1 after LSG as well as the associated costs. Methods We conducted a retrospective review of a prospectively collected database that included 200 patients who underwent LSG for severe obesity between 2011 and 2014. Primary outcome measures were the incidence of staple line leaks and the results of Gastrografin swallow tests. We obtained imaging costs from appropriate hospital departments. Results Gastrografin swallow was obtained on postoperative day 1 for all 200 patients who underwent LSG. Three patients (1.5%) were found to have staple line leaks. Gastrograffin swallows yielded 1 true positive result and 2 false negatives. The false negatives were subsequently diagnosed on computed tomography (CT) scan. The sensitivity of Gastrografin swallow in this study was 33%. For 200 patients, the total direct cost of the Gastrografin swallows was $35 000. Conclusion The use of routine upper gastrointestinal contrast studies for early detection of staple line leaks has low sensitivity and is costly. We recommend selective use of CT instead. PMID:28742012

The usefulness and costs of routine contrast studies after laparoscopic sleeve gastrectomy for detecting staple line leaks.

PubMed

Terterov, Dimitry; Leung, Philemon Ho-Yan; Twells, Laurie K; Gregory, Deborah M; Smith, Chris; Boone, Darrell; Pace, David

2017-09-01

Although laparoscopic sleeve gastrectomy (LSG) has been shown to be a safe and effective treatment for severe obesity (body mass index ≥ 35), staple line leaks remain a major complication and account for a substantial portion of the procedure's morbidity and mortality. Many centres performing LSG routinely obtain contrast studies on postoperative day 1 for early detection of staple line leaks. We examined the usefulness of Gastrografin swallow as an early detection test for staple line leaks on postoperative day 1 after LSG as well as the associated costs. We conducted a retrospective review of a prospectively collected database that included 200 patients who underwent LSG for severe obesity between 2011 and 2014. Primary outcome measures were the incidence of staple line leaks and the results of Gastrografin swallow tests. We obtained imaging costs from appropriate hospital departments. Gastrografin swallow was obtained on postoperative day 1 for all 200 patients who underwent LSG. Three patients (1.5%) were found to have staple line leaks. Gastrograffin swallows yielded 1 true positive result and 2 false negatives. The false negatives were subsequently diagnosed on computed tomography (CT) scan. The sensitivity of Gastrografin swallow in this study was 33%. For 200 patients, the total direct cost of the Gastrografin swallows was $35 000. The use of routine upper gastrointestinal contrast studies for early detection of staple line leaks has low sensitivity and is costly. We recommend selective use of CT instead.

The minimal leak test technique for endotracheal cuff maintenance.

PubMed

Harvie, D A; Darvall, J N; Dodd, M; De La Cruz, A; Tacey, M; D'Costa, R L; Ward, D

2016-09-01

Endotracheal tube (ETT) cuff pressure management is an essential part of airway management in intubated and mechanically ventilated patients. Both under- and over-inflation of the ETT cuff can lead to patient complications, with an ideal pressure range of 20-30 cmH 2 O defined. A range of techniques are employed to ensure adequate ETT cuff inflation, with little comparative data. We performed an observational cross-sectional study in a tertiary metropolitan ICU, assessing the relationship between the minimal leak test and cuff manometry. Forty-five mechanically ventilated patients, over a three-month period, had ETT cuff manometry performed at the same time as their routine cuff maintenance (minimal leak test). Bedside nurse measurements were compared with investigator measurements. At the endpoint of cuff inflation, 20 of 45 patients (44%) had cuff pressures between 20 and 30 cmH 2 O; 11 of 45 patients (24%) had cuff pressures <20 cmH 2 O; 14 of 45 patients (31%) had cuff pressures ≥30 cmH 2 O. Univariate analysis demonstrated an association between both patient obesity and female gender requiring less ETT cuff volume ( P =0.008 and P <0.001 respectively), though this association was lost on multivariate analysis. No association was demonstrated between any measured variables and cuff pressures. Inter-operator reliability in performing the minimal leak test showed no evidence of bias between nurse and investigators (Pearson coefficient = 0.897). We conclude the minimal leak test for maintenance of ETT cuffs leads to both over- and under-inflation, and alternative techniques, such as cuff manometry, should be employed.

40 CFR 280.44 - Methods of release detection for piping.

Code of Federal Regulations, 2012 CFR

2012-07-01

... accordance with the following: (a) Automatic line leak detectors. Methods which alert the operator to the... pounds per square inch line pressure within 1 hour. An annual test of the operation of the leak detector...

40 CFR 280.44 - Methods of release detection for piping.

Code of Federal Regulations, 2011 CFR

2011-07-01

... accordance with the following: (a) Automatic line leak detectors. Methods which alert the operator to the... pounds per square inch line pressure within 1 hour. An annual test of the operation of the leak detector...

40 CFR 280.44 - Methods of release detection for piping.

Code of Federal Regulations, 2013 CFR

2013-07-01

... accordance with the following: (a) Automatic line leak detectors. Methods which alert the operator to the... pounds per square inch line pressure within 1 hour. An annual test of the operation of the leak detector...

40 CFR 280.44 - Methods of release detection for piping.

Code of Federal Regulations, 2014 CFR

2014-07-01

... accordance with the following: (a) Automatic line leak detectors. Methods which alert the operator to the... pounds per square inch line pressure within 1 hour. An annual test of the operation of the leak detector...

40 CFR 280.44 - Methods of release detection for piping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... accordance with the following: (a) Automatic line leak detectors. Methods which alert the operator to the... pounds per square inch line pressure within 1 hour. An annual test of the operation of the leak detector...

Natural air leak test without submergence for spontaneous pneumothorax.

PubMed

Uramoto, Hidetaka; Tanaka, Fumihiro

2011-12-24

Postoperative air leaks are frequent complications after surgery for a spontaneous pneumothorax (SP). We herein describe a new method to test for air leaks by using a transparent film and thoracic tube in a closed system. Between 2005 and 2010, 35 patients underwent a novel method for evaluating air leaks without submergence, and their clinical records were retrospectively reviewed. The data on patient characteristics, surgical details, and perioperative outcomes were analyzed. The differences in the clinical background and intraoperative factors did not reach a statistically significant level between the new and classical methods. The incidence of recurrence was also equivalent to the standard method. However, the length of the operation and drainage periods were significantly shorter in patients evaluated using the new method than the conventional method. Further, no postoperative complications were observed in patients evaluated using the new method. This simple technique is satisfactorily effective and does not result in any complications.

Seven Ventilators Challenged With Leaks During Neonatal Nasal CPAP: An Experimental Pilot Study.

PubMed

Drevhammar, Thomas; Nilsson, Kjell; Zetterström, Henrik; Jonsson, Baldvin

2015-07-01

Nasal CPAP is the most common respiratory support for neonates. Several factors are considered important for effective treatment, including leaks at the patient interface and the delivery of pressure-stable CPAP. Investigations of pressure stability during leaks should include both the change in the mean delivered CPAP and the pressure variation during each breath. The aim of this study was to examine the response of ventilators delivering nasal CPAP when challenged with leaks at the patient interface. Seven ventilators providing nasal CPAP at 4 cm H2O were challenged with leaks during simulated neonatal breathing. Leak was applied for 15 consecutive breaths at a constant level (1-4 L/min). The 2 aspects of pressure stability were evaluated by measuring the mean delivered CPAP and the amplitude of pressure swings before, during, and after leaks. The ability to maintain the delivered CPAP and the amplitude of pressure swings varied greatly among the 7 ventilators before, during, and after leaks. Four of the ventilators tested have built-in leak compensation. There was no simple relationship between maintaining delivered CPAP during leaks and providing CPAP with low pressure swing amplitude. Maintaining the delivered CPAP and providing this without pressure swings are 2 separate aspects of pressure stability, and investigations concerning the clinical importance of pressure stability should address both aspects. This study also shows that compensation for leaks does not necessarily provide pressure-stable CPAP. Copyright © 2015 by Daedalus Enterprises.

Risk factors for cerebrospinal fluid leak in pediatric patients undergoing endoscopic endonasal skull base surgery.

PubMed

Stapleton, Amanda L; Tyler-Kabara, Elizabeth C; Gardner, Paul A; Snyderman, Carl H; Wang, Eric W

2017-02-01

To determine the risk factors associated with cerebrospinal fluid (CSF) leak following endoscopic endonasal surgery (EES) for pediatric skull base lesions. Retrospective chart review of pediatric patients (ages 1 month to 18 years) treated for skull base lesions with EES from 1999 to 2014. Five pathologies were reviewed: craniopharyngioma, clival chordoma, pituitary adenoma, pituitary carcinoma, and Rathke's cleft cyst. Fisher's exact tests were used to evaluate the different factors to determine which had a statistically higher risk of leading to a post-operative CSF leak. 55 pediatric patients were identified who underwent 70 EES's for tumor resection. Of the 70 surgeries, 47 surgeries had intraoperative CSF leaks that were repaired at the time of surgery. 11 of 47 (23%) surgeries had post-operative CSF leaks that required secondary operative repair. Clival chordomas had the highest CSF leak rate at 36%. There was no statistical difference in leak rate based on the type of reconstruction, although 28% of cases that used a vascularized flap had a post-operative leak, whereas only 9% of those cases not using a vascularized flap had a leak. Post-operative hydrocephalus and perioperative use of a lumbar drain were not significant risk factors. Pediatric patients with an intra-operative CSF leak during EES of the skull base have a high rate of post-operative CSF leaks. Clival chordomas appear to be a particularly high-risk group. The use of vascularized flaps and perioperative lumbar drains did not statistically decrease the rate of post-operative CSF leak. Copyright © 2017 Elsevier B.V. All rights reserved.

Lymphangiography in the Diagnosis and Localization of Various Chyle Leaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deso, Steve; Ludwig, Benjamin; Kabutey, Nii-Kabu

2012-02-15

Purpose: Chyle leaks are rare entities infrequently encountered by most physicians. However, large centers providing advanced surgical care are inevitably confronted with chyle leaks as a complication of surgery, an extension of disease, or as a primary disorder. Regardless of the etiology, proper diagnosis and localization are paramount in the management of any chyle leak. Materials and Methods: Here we present 16 patients with 17 chyle leaks (5 chyluria, 8 chylothorax, and 4 chylous ascites) who underwent bipedal lymphangiography (LAG) and postprocedure computed tomography (CT) imaging. Results: In each case, the source of the chyle leak was identified and properlymore » localized to guide further treatment. Of the 16 patients who underwent LAG and postprocedure CT imaging, the initial LAG alone provided the diagnosis and localized the chyle leak in 4 patients (25%); the postprocedure CT imaging provided the diagnosis and localized the chyle leak in 6 patients (37.5%); and the two modalities were equal in the diagnosing and localizing the chyle leak in the remaining 6 patients (37.5%)ConclusionThese cases highlight the unparalleled abilities of LAG and the added benefit of post-LAG CT imaging in the diagnosis and fine anatomic localization of chyle leaks. In addition, these cases demonstrate the retained utility of LAG in these investigations despite the development of alternative tests involving CT, magnetic resonance imaging, and nuclear medicine imaging.« less

Technical factors associated with anastomotic leak after Roux-en-Y gastric bypass.

PubMed

Smith, Mark D; Adeniji, Abidemi; Wahed, Abdus S; Patterson, Emma; Chapman, William; Courcoulas, Anita P; Dakin, Gregory; Flum, David; McCloskey, Carol; Mitchell, James E; Pomp, Alfons; Staten, Myrlene; Wolfe, Bruce

2015-01-01

Anastomotic leak is one of the most serious complications after Roux-en-Y gastric bypass (RYGB). Our objective was to examine the relationship between technical factors and incidence of clinically relevant anastomotic leak after RYGB in longitudinal assessment of bariatric surgery (LABS). The setting of the study was 11 bariatric centers in the United States, university, and private practice. Patient characteristics, technical factors of surgery, and postoperative outcomes were assessed by trained researchers using standardized protocols. Correlation of surgical factors of patients undergoing RYGB (n = 4444) with the incidence of postoperative anastomotic leak was assessed by univariate χ(2) analysis. Forty-four participants (1.0%, 95% CI .7%-1.3%) experienced a clinically relevant anastomotic leak. Of these, 39 (89%) underwent abdominal reoperation and 3 (7%) died. Technical factors associated with anastomotic leak were open surgery (P<.0001), revision surgery (P<.0001), and use of an abdominal drain (P = .02). Provocative leak testing, method of gastrojejunostomy, and use of fibrin sealant were not associated with anastomotic leak. Anastomotic leak after RYGB was rare (1.0%). Most cases required reintervention; however, the majority (93%) recovered from this event. Open surgery, revision surgery, and routine drain placement were associated with increased leak rate. Some of these findings may be due to differences in preoperative patient risk. Copyright © 2015 American Society for Metabolic and Bariatric Surgery. All rights reserved.

40 CFR 86.319-79 - Analyzer checks and calibrations; frequency and overview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... during testing, perform the following: (1) Leak check the pressure side of the system (see § 86.328). If the option described in § 86.328(b)(2) is used, a pressure leak check is not required. (2) Calibrate... need be checked only every 90 days. (d) At least once every 90 days during testing check the water...

Anastomotic leak after colorectal resection: A population-based study of risk factors and hospital variation.

PubMed

Nikolian, Vahagn C; Kamdar, Neil S; Regenbogen, Scott E; Morris, Arden M; Byrn, John C; Suwanabol, Pasithorn A; Campbell, Darrell A; Hendren, Samantha

2017-06-01

Anastomotic leak is a major source of morbidity in colorectal operations and has become an area of interest in performance metrics. It is unclear whether anastomotic leak is associated primarily with surgeons' technical performance or explained better by patient characteristics and institutional factors. We sought to establish if anastomotic leak could serve as a valid quality metric in colorectal operations by evaluating provider variation after adjusting for patient factors. We performed a retrospective cohort study of colorectal resection patients in the Michigan Surgical Quality Collaborative. Clinically relevant patient and operative factors were tested for association with anastomotic leak. Hierarchical logistic regression was used to derive risk-adjusted rates of anastomotic leak. Of 9,192 colorectal resections, 244 (2.7%) had a documented anastomotic leak. The incidence of anastomotic leak was 3.0% for patients with pelvic anastomoses and 2.5% for those with intra-abdominal anastomoses. Multivariable analysis showed that a greater operative duration, male sex, body mass index >30 kg/m 2 , tobacco use, chronic immunosuppressive medications, thrombocytosis (platelet count >400 × 10 9 /L), and urgent/emergency operations were independently associated with anastomotic leak (C-statistic = 0.75). After accounting for patient and procedural risk factors, 5 hospitals had a significantly greater incidence of postoperative anastomotic leak. This population-based study shows that risk factors for anastomotic leak include male sex, obesity, tobacco use, immunosuppression, thrombocytosis, greater operative duration, and urgent/emergency operation; models including these factors predict most of the variation in anastomotic leak rates. This study suggests that anastomotic leak can serve as a valid metric that can identify opportunities for quality improvement. Copyright © 2017 Elsevier Inc. All rights reserved.

Continuous time-resolved regional methane leak detection with on-line background estimation using a novel combination of dual frequency comb laser spectroscopy and atmospheric inversions

NASA Astrophysics Data System (ADS)

Alden, C. B.; Coburn, S.; Wright, R.; Baumann, E.; Cossel, K.; Sweeney, C.; Ghosh, S.; Newbury, N.; Prasad, K.; Coddington, I.; Rieker, G. B.

2017-12-01

Advances in natural gas extraction technology have led to increased US production and transport activity, and as a consequence, an increased need for monitoring of methane leaks. Current leak detection methods provide time snapshots, and not continuous, time-varying estimates of emissions. Most approaches also require specific atmospheric conditions, operators, or the use of a tracer gas, requiring site access. Given known intermittency in fugitive methane emissions, continuous monitoring is a critical need for emissions mitigation. We present a novel leak detection method that employs dual frequency comb spectrometry to offer continuous, autonomous, leak detection and quantification over square-km scale areas. The spectrometer is situated in a field of natural gas pads, and a series of retroreflectors around the field direct light back to a detector. The laser light spans 1620-1680 nm with 0.002 nm line spacing, measuring thousands of individual absorption features from multiple species. The result is high-stability trace gas (here CH4, CO2, and H2O) measurements over long (1 km+) open paths through the atmosphere. Measurements are used in an atmospheric inversion to estimate the time variability of emissions at each location of interest. Importantly, the measurement framework and inversion solve explicitly for background concentrations, which vary rapidly in fields of active oil and gas production. We present the results of controlled-leak field tests in rural Colorado. We demonstrate the ability to locate and size a leak located 1 km away from the spectrometer and varying in strength from 1.5 to 7.7 g/min, resulting in mean atmospheric enhancements of 20 ppb. The inversion correctly identifies when the leak turned on and off over a 24-hour period, and determines the mean leak strength to within 10% of the true controlled rate. We further demonstrate the ability of the system to correctly locate and size the start and end of simultaneous 2.7 to 4.8 g/min leaks from 2 sources in a field of 5 potential leak locations. Finally, we present the results of leak-detection tests in active oil and gas fields in the Denver Julesburg Basin, where background methane is complex.

The use of perfluorocarbon tracer (PFT) technology to determine fine leaks in hermeticity testing of semiconductor devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dietz, R.N.

1991-05-01

The BNL-developed perfluorocarbon tracer (PFT) technology includes a rapid-response real-time (5-second) analyzer (COPS) which can detect PFT concentrations as low as 1 {times} 10{sup {minus}11} mL/mL and a concentrating analyzer (DTA) which can measure down to 1 {times} 10{sup {minus}12} mL of PFT--separately quantifying up to 4 PFTs in a 6-min cycle time or less. Based on this technology, experimental leak- rate design concepts are proposed for determining the effectiveness (hermeticity) of the seal of semiconductor devices with internal cavities from 0.01 to 1 mL. The concept is based on pressurizing with PFT-containing air for 60 seconds, purging with PFT-freemore » air for 60 seconds, pressure pulsing with air or He to extract the PFT leaked into the internal volume, and finally detecting the PFT vapor concentration with one of the two instruments. The COPS analyzer can quantify gross leaks from 1 {times} 10{sup {minus}7} to 1 {times} 10{sup {minus}3} mL/s in just 3 minutes for the complete test. The more-sensitive concentrating analyzer (DTA) can quantify fine leaks from 0.2 {times} 10{sup {minus}8} to 1 {times} 10{sup {minus}3} mL/s in just 12 minutes for the complete test; the latter procedure includes two determinations per test. 5 refs., 2 tabs.« less

A method for simulating the entire leaking process and calculating the liquid leakage volume of a damaged pressurized pipeline.

PubMed

He, Guoxi; Liang, Yongtu; Li, Yansong; Wu, Mengyu; Sun, Liying; Xie, Cheng; Li, Feng

2017-06-15

The accidental leakage of long-distance pressurized oil pipelines is a major area of risk, capable of causing extensive damage to human health and environment. However, the complexity of the leaking process, with its complex boundary conditions, leads to difficulty in calculating the leakage volume. In this study, the leaking process is divided into 4 stages based on the strength of transient pressure. 3 models are established to calculate the leaking flowrate and volume. First, a negative pressure wave propagation attenuation model is applied to calculate the sizes of orifices. Second, a transient oil leaking model, consisting of continuity, momentum conservation, energy conservation and orifice flow equations, is built to calculate the leakage volume. Third, a steady-state oil leaking model is employed to calculate the leakage after valves and pumps shut down. Moreover, sensitive factors that affect the leak coefficient of orifices and volume are analyzed respectively to determine the most influential one. To validate the numerical simulation, two types of leakage test with different sizes of leakage holes were conducted from Sinopec product pipelines. More validations were carried out by applying commercial software to supplement the experimental insufficiency. Thus, the leaking process under different leaking conditions are described and analyzed. Copyright © 2017 Elsevier B.V. All rights reserved.

Leak test fitting

DOEpatents

Pickett, P.T.

A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

Leak test fitting

DOEpatents

Pickett, Patrick T.

1981-01-01

A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

KSC-2010-5880

NASA Image and Video Library

2010-12-17

CAPE CANAVERAL, Fla. -- Team members stationed at consoles in the Launch Control Center at NASA's Kennedy Space Center in Florida monitor space shuttle Discovery's external fuel tank as it is loaded with more than 535,000 gallons of cryogenic propellants. From back, are Assistant Launch Orbiter Test Conductor Mark Taffet, Launch Orbiter Test Conductor John Kracsun, STS-133 NASA Test Director Steve Payne, NASA Commentator Allard Beutel, NASA Test Director Jeremy Graeber and STS-133 Assistant NASA Test Director Jeff Spaulding. During today's tanking test, the team is paying particular attention to the external tank's ribbed intertank region. Beginning tomorrow, engineers will evaluate data on 21-foot-long, U-shaped aluminum brackets, called stringers, and the newly replaced ground umbilical carrier plate (GUCP). Discovery's first launch attempt for STS-133 was scrubbed in early November due to a hydrogen gas leak at the GUCP. In order to perform additional analysis on the tank, Discovery will be rolled back to the Vehicle Assembly Building, a move that is planned for next week. The next launch opportunity is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Cory Huston

Modeling and measurement of the performance of a branched conduit sampling system in a mass spectrometer leak detector

NASA Technical Reports Server (NTRS)

Russell, John M.

1994-01-01

In the leak testing of a large engineering system, one may distinguish three stages, namely leakage measurement by an overall enclosure, leak location, and leakage measurement by a local enclosure. Sniffer probes attached to helium mass spectrometer leak detectors are normally designed for leak location, a qualitative inspection technique intended to pinpoint where a leak is but not to quantify its rate of discharge. The main conclusion of the present effort is that local leakage measurement by a leak detector with a sniffer probe is feasible provided one has: (1) quantitative data on the performance of the mass separator cell (a device interior to the unit where the stream of fluid in the sample line branches); and (2) a means of stabilizing the mass transfer boundary layer that is created near a local leak site when a sniffer probe is placed in its immediate vicinity. Theoretical models of the mass separator cell are provided and measurements of the machine-specific parameters in the formulas are presented. A theoretical model of a porous probe end for stabilizing the mass transfer boundary is also presented.

Modeling and measurement of the performance of a branched conduit sampling system in a mass spectrometer leak detector

NASA Astrophysics Data System (ADS)

Russell, John M.

1994-10-01

In the leak testing of a large engineering system, one may distinguish three stages, namely leakage measurement by an overall enclosure, leak location, and leakage measurement by a local enclosure. Sniffer probes attached to helium mass spectrometer leak detectors are normally designed for leak location, a qualitative inspection technique intended to pinpoint where a leak is but not to quantify its rate of discharge. The main conclusion of the present effort is that local leakage measurement by a leak detector with a sniffer probe is feasible provided one has: (1) quantitative data on the performance of the mass separator cell (a device interior to the unit where the stream of fluid in the sample line branches); and (2) a means of stabilizing the mass transfer boundary layer that is created near a local leak site when a sniffer probe is placed in its immediate vicinity. Theoretical models of the mass separator cell are provided and measurements of the machine-specific parameters in the formulas are presented. A theoretical model of a porous probe end for stabilizing the mass transfer boundary is also presented.

Evaluating All-Metal Valves for Use in a Tritium Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Houk, L.; Payton, A.

In the tritium gas processing system, it is desired to minimize polymer components due to their degradation from tritium exposure (beta decay). One source of polymers in the tritium process is valve components. A vendor has been identified that manufactures a valve that is marketed as being made from all-metal construction. This manufacturer, Ham-Let Group, manufactures a diaphragm valve (3LE series) that claims to be made entirely of metal. SRNL procured twelve (12) Ham-Let diaphragm valves for characterization and evaluation. The characterization tests include identification of the maximum pressure of these valves by performing pressure and burst tests. Leak testsmore » were performed to ensure the valves do not exceed the acceptable leak rate for tritium service. These valves were then cycled in a nitrogen gas and/or vacuum environment to ensure they would be durable in a process environment. They were subsequently leak tested per ASTM protocol to ensure that the valves maintained their leak tight integrity. A detailed material analysis was also conducted to determine hydrogen and tritium compatibility.« less

Chemochromic Hydrogen Leak Detectors

NASA Technical Reports Server (NTRS)

Roberson, Luke; Captain, Janine; Williams, Martha; Smith, Trent; Tate, LaNetra; Raissi, Ali; Mohajeri, Nahid; Muradov, Nazim; Bokerman, Gary

2009-01-01

At NASA, hydrogen safety is a key concern for space shuttle processing. Leaks of any level must be quickly recognized and addressed due to hydrogen s lower explosion limit. Chemo - chromic devices have been developed to detect hydrogen gas in several embodiments. Because hydrogen is odorless and colorless and poses an explosion hazard, there is an emerging need for sensors to quickly and accurately detect low levels of leaking hydrogen in fuel cells and other advanced energy- generating systems in which hydrogen is used as fuel. The device incorporates a chemo - chromic pigment into a base polymer. The article can reversibly or irreversibly change color upon exposure to hydrogen. The irreversible pigment changes color from a light beige to a dark gray. The sensitivity of the pigment can be tailored to its application by altering its exposure to gas through the incorporation of one or more additives or polymer matrix. Furthermore, through the incorporation of insulating additives, the chemochromic sensor can operate at cryogenic temperatures as low as 78 K. A chemochromic detector of this type can be manufactured into any feasible polymer part including injection molded plastic parts, fiber-spun textiles, or extruded tapes. The detectors are simple, inexpensive, portable, and do not require an external power source. The chemochromic detectors were installed and removed easily at the KSC launch pad without need for special expertise. These detectors may require an external monitor such as the human eye, camera, or electronic detector; however, they could be left in place, unmonitored, and examined later for color change to determine whether there had been exposure to hydrogen. In one type of envisioned application, chemochromic detectors would be fabricated as outer layers (e.g., casings or coatings) on high-pressure hydrogen storage tanks and other components of hydrogen-handling systems to provide visible indications of hydrogen leaks caused by fatigue failures or other failures in those systems. In another type of envisioned application, chemochromic detectors of this type could be optoelectronically instrumented for monitoring to provide measured digital indications of color changes indicative of the presence of hydrogen.

75 FR 47242 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-14, DC-9-15, and DC-9-15F...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-05

... the inboard side of the rear spar upper cap, which resulted from stress corrosion. We are proposing... the left or right center wing rear spar, which could cause a possible fuel leak, damage to the wing... the center wing rear spar that resulted from stress corrosion. We issued that AD to detect and correct...

Vapor intrusion risk of lead scavengers 1,2-dibromoethane (EDB) and 1,2-dichloroethane (DCA).

PubMed

Ma, Jie; Li, Haiyan; Spiese, Richard; Wilson, John; Yan, Guangxu; Guo, Shaohui

2016-06-01

Vapor intrusion of synthetic fuel additives represented a critical yet still neglected problem at sites impacted by petroleum fuel releases. This study used an advanced numerical model to simulate the vapor intrusion risk of lead scavengers 1,2-dibromoethane (ethylene dibromide, EDB) and 1,2-dichloroethane (DCA) under different site conditions. We found that simulated EDB and DCA indoor air concentrations can exceed USEPA screening level (4.7 × 10(-3) μg/m(3) for EDB and 1.1 × 10(-1) μg/m(3) for DCA) if the source concentration is high enough (is still within the concentration range found at leaking UST site). To evaluate the chance that vapor intrusion of EDB might exceed the USEPA screening levels for indoor air, the simulation results were compared to the distribution of EDB at leaking UST sites in the US. If there is no degradation of EDB or only abiotic degradation of EDB, from 15% to 37% of leaking UST sites might exceed the USEPA screening level. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the screening criteria for petroleum hydrocarbon may not provide sufficient protectiveness for fuel releases containing EDB and DCA. Based on a thorough literature review, we also compiled previous published data on the EDB and DCA groundwater source concentrations and their degradation rates. These data are valuable in evaluating EDB and DCA vapor intrusion risk. In addition, a set of refined attenuation factors based on site-specific information (e.g., soil types, source depths, and degradation rates) were provided for establishing site-specific screening criteria for EDB and DCA. Overall, this study points out that lead scavengers EDB and DCA may cause vapor intrusion problems. As more field data of EDB and DCA become available, we recommend that USEPA consider including these data in the existing PVI database and possibly revising the PVI Guidance as necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of an Interferometric Sensor for In-Space Detection of Gas Leaks

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Korman, Valentin; Sinko, John; Hendrickson, Adam

2009-01-01

Space mission planning often involves long-term storage of volatile liquids or high-pressure gases. These may include cryogenic fuels and oxidizers, high-pressure gases, and life-support-critical consumables. The risk associated with the storage of fluids and gases in space systems has long been an issue and the ability to retain these fluids is often tied to mission success. A leak in the storage or distribution system can cause many different problems, including a simple, but mission endangering, loss of inventory or, in severe cases, unbalanced thrust loads on a flight vehicle. Cryogenic propellants are especially difficult to store, especially over a long duration. The propellant can boil off and be lost through the insulating walls of the tank or simple thermal cycling of the fittings, valves, and propellant feed lines may unseat seals allowing the fluid to escape. Current NASA missions call for long-duration in-space storage of propellants, oxidizers, and life support supplies. Leaks of a scale detectable through a pressure drop in the storage tank are often catastrophic and have long been the focus of ground-based mitigation efforts where redundant systems are often employed. However, there is presently no technology available for detecting and monitoring low-level, but still mission-endangering, gas leaks in space. Standard in-space gas detection methods either have a very limited pressure range over which they operate effectively or are limited to certain gases. Mass spectrometer systems are able to perform the detection tasks, but their size, mass and use of high voltage, which could potentially lead to an arc that ignites a combustible propellent, severely limit their usefulness in a space system. In this paper, we present results from testing of the light-based interferometric gas monitoring and leak detection sensor shown in Fig. 1. The output of the sensor is an interference fringe pattern that is a function of the gas density, and commensurate index of refraction, in the sample region. Changes in the density of gas cause the interference fringes to move across a photodiode detector, providing a temporal history of the leak. The sensor is fiber coupled and constructed from solid optics, allowing for placement almost anywhere on the spacecraft. It is also advantageous in that it consumes very little power and does not introduce an ignition source. Data are presented demonstrating the capability of the sensor to measure density variations in different gas species. In addition, the transient response of the sensor in vacuum is demonstrated. These data extend and improve upon the results previously presented by the authors in Ref. [1].

Connective tissue spectrum abnormalities associated with spontaneous cerebrospinal fluid leaks: a prospective study.

PubMed

Reinstein, Eyal; Pariani, Mitchel; Bannykh, Serguei; Rimoin, David L; Schievink, Wouter I

2013-04-01

We aimed to assess the frequency of connective tissue abnormalities among patients with cerebrospinal fluid (CSF) leaks in a prospective study using a large cohort of patients. We enrolled a consecutive group of 50 patients, referred for consultation because of CSF leak. All patients have been carefully examined for the presence of connective tissue abnormalities, and based on findings, patients underwent genetic testing. Ancillary diagnostic studies included echocardiography, eye exam, and histopathological examinations of skin and dura biopsies in selected patients. We identified nine patients with heritable connective tissue disorders, including Marfan syndrome, Ehlers-Danlos syndrome and other unclassified forms. In seven patients, spontaneous CSF leak was the first noted manifestation of the genetic disorder. We conclude that spontaneous CSF leaks are associated with a spectrum of connective tissue abnormalities and may be the first noted clinical presentation of the genetic disorder. We propose that there is a clinical basis for considering spontaneous CSF leak as a clinical manifestation of heritable connective tissue disorders, and we suggest that patients with CSF leaks should be screened for connective tissue and vascular abnormalities.

Detection of CO2 leaks from carbon capture and storage sites to the atmosphere with combined CO2 and O2 measurements

NASA Astrophysics Data System (ADS)

van Leeuwen, Charlotte; Meijer, Harro A. J.

2015-04-01

One of the main issues in carbon capture and storage (CCS) is the possibility of leakage of CO2 from the storage reservoir to the atmosphere, both from a public health and a climate change combat perspective. Detecting these leaks in the atmosphere is difficult due to the rapid mixing of the emitted CO2 with the surrounding air masses and the high natural variability of the atmospheric CO2 concentration. Instead of measuring only the CO2 concentration of the atmosphere, its isotopes or chemical tracers that are released together with the CO2, our method uses O2 measurements in addition to CO2 measurements to detect a leak from a CCS site. CO2 and O2 are coupled in most processes on earth. In photosynthesis, plants take up CO2 and release O2 at the same time. In respiration and fossil fuel burning, O2 is consumed while CO2 is released. In case of a leak from a CCS site, however, there is no relationship between CO2 and O2. A CO2 leak can therefore be distinguished from other sources of CO2 by looking at the atmospheric CO2-O2 ratio. A natural increase of the CO2 concentration is accompanied by a drop in the O2 concentration, while an increase in the CO2 concentration caused by a leak from a CCS site does not have any effect on the O2 concentration. To demonstrate this leak detection strategy we designed and built a transportable CO2 and O2 measurement system, that is capable of measuring the relatively minute (ppm's variations on a 21% concentration) changes in the O2 concentration. The system comprises of three cases that contain the instrumentation and gas handling equipment, the gas cylinders used as reference and calibration gases and a drying system, respectively. Air is pumped to the system from an air inlet that is placed in a small tower in the field. At the conference, we will demonstrate the success of leak detection with our system by showing measurements of several CO2 release experiments, where CO2 was released at a small distance from the air inlet of our instrument.

Refrigerant leak detector

NASA Technical Reports Server (NTRS)

Byrne, E. J.

1979-01-01

Quantitative leak detector visually demonstrates refrigerant loss from precision volume of large refrigeration system over established period of time from single test point. Mechanical unit is less costly than electronic "sniffers" and is more reliable due to absence of electronic circuits that are susceptible to drift.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W.; Mcwilliams, A.; Skidmore, E.

The 9975 Type B shipping package is used within the DOE complex for shipping special nuclear materials. This package is re-certified annually in accordance with Safety Analysis Report requirements. The package is also used at the Savannah River Site as part of the long-term storage configuration of special nuclear materials. As such, the packages do not undergo annual recertification during storage, with uncertainty as to how long some of the package components will meet their functional requirements in the storage environment. The packages are currently approved for up to 15 years storage, and work continues to provide a technical basismore » to extend that period. This paper describes efforts by the Savannah River National Laboratory (SRNL) to extend the service life estimate of Viton® GLT and GLT-S fluoroelastomer O-rings used in the 9975 shipping package. O-rings of both compositions are undergoing accelerated aging at elevated temperature, and are periodically tested for compression stress relaxation (CSR) behavior and leak performance. The CSR behavior of O-rings was evaluated at temperatures from 79 °C to 177 °C. These collective data were used to develop predictive models for extrapolation of CSR behavior to relevant service temperatures (< 75 °C). O-rings were also aged in Primary Containment Vessel (PCV) fixtures at temperatures ranging from 79 °C to 232 °C. The fixtures are helium leak tested periodically to determine if they remain leak-tight. The PCV fixture tests demonstrate that the 9975 O-rings will remain leak-tight at temperatures up to 149 °C for 3 years or more, and no leak failures have been observed with up to 8 years aging at 93 °C. Significantly longer periods of leak-tight service are expected at the lower temperatures actually experienced in the storage environment. The predictive model developed from the CSR data conservatively indicates a service life of more than 20 years at the bounding temperature of 75 °C. Although the relationship between CSR behavior and leak-tight performance has not been established for this design, the CSR predictions for this O-ring are conservative relative to leak-tight performance to date.« less

Quantitative computed tomography versus spirometry in predicting air leak duration after major lung resection for cancer.

PubMed

Ueda, Kazuhiro; Kaneda, Yoshikazu; Sudo, Manabu; Mitsutaka, Jinbo; Li, Tao-Sheng; Suga, Kazuyoshi; Tanaka, Nobuyuki; Hamano, Kimikazu

2005-11-01

Emphysema is a well-known risk factor for developing air leak or persistent air leak after pulmonary resection. Although quantitative computed tomography (CT) and spirometry are used to diagnose emphysema, it remains controversial whether these tests are predictive of the duration of postoperative air leak. Sixty-two consecutive patients who were scheduled to undergo major lung resection for cancer were enrolled in this prospective study to define the best predictor of postoperative air leak duration. Preoperative factors analyzed included spirometric variables and area of emphysema (proportion of the low-attenuation area) that was quantified in a three-dimensional CT lung model. Chest tubes were removed the day after disappearance of the air leak, regardless of pleural drainage. Univariate and multivariate proportional hazards analyses were used to determine the influence of preoperative factors on chest tube time (air leak duration). By univariate analysis, site of resection (upper, lower), forced expiratory volume in 1 second, predicted postoperative forced expiratory volume in 1 second, and area of emphysema (< 1%, 1% to 10%, > 10%) were significant predictors of air leak duration. By multivariate analysis, site of resection and area of emphysema were the best independent determinants of air leak duration. The results were similar for patients with a smoking history (n = 40), but neither forced expiratory volume in 1 second nor predicted postoperative forced expiratory volume in 1 second were predictive of air leak duration. Quantitative CT is superior to spirometry in predicting air leak duration after major lung resection for cancer. Quantitative CT may aid in the identification of patients, particularly among those with a smoking history, requiring additional preventive procedures against air leak.

Specificity and sensitivity of noninvasive measurement of pulmonary vascular protein leak.

PubMed

Dauber, I M; Pluss, W T; VanGrondelle, A; Trow, R S; Weil, J V

1985-08-01

Noninvasive techniques employing external counting of radiolabeled protein have the potential for measuring pulmonary vascular protein permeability, but their specificity and sensitivity remain unclear. We tested the specificity and sensitivity of a double-radioisotope method by injecting radiolabeled albumin (131I) and erythrocytes (99mTc) into anesthetized dogs and measuring the counts of each isotope for 150 min after injection with an external gamma probe fixed over the lung. We calculated the rate of increase of albumin counts measured by the probe (which reflects the rate at which protein leaks into the extravascular space). To assess permeability we normalized the rate of increase in albumin counts for changes in labeled erythrocyte signal to minimize influence of changes in vascular surface area and thus derived an albumin leak index. We measured the albumin leak index and gravimetric lung water during hydrostatic edema (acutely elevating left atrial pressure by left atrial balloon inflation: mean pulmonary arterial wedge pressure = 22.6 Torr) and in lung injury edema induced by high- (1.0 g/kg) and low-dose (0.25 g/kg) intravenous thiourea. To test specificity we compared hydrostatic and high-dose thiourea edema. The albumin leak index increased nearly fourfold from control after thiourea injury (27.2 +/- 2.3 X 10-4 vs. 7.6 +/- 0.9 X 10-4 min-1) but did not change from control levels after elevating left atrial pressure (8.9 +/- 1.2 X 10-4 min-1) despite comparable increases in gravimetric lung water. To test sensitivity we compared low-dose thiourea with controls. Following low-dose thiourea, the albumin leak index nearly doubled despite the absence of a measurable increase in lung water. We conclude that a noninvasive double radioisotope measurement of pulmonary vascular protein leak, employing external counting techniques and a simplified method of calculation, is specific for lung injury and is also sensitive enough to detect lung injury insufficient to produce detectable pulmonary edema.

Tensile Properties and Integrity of Clean Room and Low-Modulus Disposable Nitrile Gloves: A Comparison of Two Dissimilar Glove Types

PubMed Central

Phalen, Robert N.; Wong, Weng kee

2012-01-01

Background: The selection of disposable nitrile exam gloves is complicated by (i) the availability of several types or formulations, (ii) product variability, and (iii) an inability of common quality control tests to detect small holes in the fingers. Differences in polymer formulation (e.g. filler and plasticizer/oil content) and tensile properties are expected to account for much of the observed variability in performance. Objectives: This study evaluated the tensile properties and integrity (leak failure rates) of two glove choices assumed to contain different amounts of plasticizers/oils. The primary aims were to determine if the tensile properties and integrity differed and if associations existed among these factors. Additional physical and chemical properties were evaluated. Methods: Six clean room and five low-modulus products were evaluated using the American Society for Testing and Materials Method D412 and a modified water-leak test to detect holes capable of passing a virus or chemical agent. Results: Significant differences in the leak failure rates and tensile properties existed between the two glove types (P ≤ 0.05). The clean room gloves were about three times more likely to have leak failures (chi-square; P = 0.001). No correlation was observed between leak failures and tensile properties. Solvent extract, an indication of added plasticizer/oil, was not associated with leak failures. However, gloves with a maximum modulus <4 MPa or area density (AD) <11 g cm−2 were about four times less likely to leak. Conclusions: On average, the low-modulus gloves were a better choice for protection against aqueous chemical or biological penetration. The observed variability between glove products indicated that glove selection cannot rely solely on glove type or manufacturer labeling. Measures of modulus and AD may aid in the selection process, in contrast with common measures of tensile strength and elongation at break. PMID:22201179

Tensile properties and integrity of clean room and low-modulus disposable nitrile gloves: a comparison of two dissimilar glove types.

PubMed

Phalen, Robert N; Wong, Weng Kee

2012-05-01

The selection of disposable nitrile exam gloves is complicated by (i) the availability of several types or formulations, (ii) product variability, and (iii) an inability of common quality control tests to detect small holes in the fingers. Differences in polymer formulation (e.g. filler and plasticizer/oil content) and tensile properties are expected to account for much of the observed variability in performance. This study evaluated the tensile properties and integrity (leak failure rates) of two glove choices assumed to contain different amounts of plasticizers/oils. The primary aims were to determine if the tensile properties and integrity differed and if associations existed among these factors. Additional physical and chemical properties were evaluated. Six clean room and five low-modulus products were evaluated using the American Society for Testing and Materials Method D412 and a modified water-leak test to detect holes capable of passing a virus or chemical agent. Significant differences in the leak failure rates and tensile properties existed between the two glove types (P ≤ 0.05). The clean room gloves were about three times more likely to have leak failures (chi-square; P = 0.001). No correlation was observed between leak failures and tensile properties. Solvent extract, an indication of added plasticizer/oil, was not associated with leak failures. However, gloves with a maximum modulus <4 MPa or area density (AD) <11 g cm(-2) were about four times less likely to leak. On average, the low-modulus gloves were a better choice for protection against aqueous chemical or biological penetration. The observed variability between glove products indicated that glove selection cannot rely solely on glove type or manufacturer labeling. Measures of modulus and AD may aid in the selection process, in contrast with common measures of tensile strength and elongation at break.

He-Ne and CW CO2 laser long-path systems for gas detection

NASA Technical Reports Server (NTRS)

Grant, W. B.

1986-01-01

This paper describes the design and testing of a laboratory prototype dual He-Ne laser system for the detection of methane leaks from underground pipelines and solid-waste landfill sites using differential absorption of radiation backscattered from topographic targets. A laboratory-prototype dual CW carbon dioxide laser system also using topographic backscatter is discussed, and measurement results for methanol are given. With both systems, it was observed that the time-varying differential absorption signal was useful in indicating the presence of a gas coming from a nearby source. Limitations to measurement sensitivity, especially the role of speckle and atmospheric turbulence, are described. The speckle results for hard targets are contrasted with those from atmospheric aerosols. The appendix gives appropriate laser lines and values of absorption coefficients for the hydrazine fuel gases.

Intraoperatively Testing the Anastomotic Integrity of Esophagojejunostomy Using Methylene Blue.

PubMed

Celik, S; Almalı, N; Aras, A; Yılmaz, Ö; Kızıltan, R

2017-03-01

Intraoperative testing of gastrointestinal anastomosis effectively ensures anastomotic integrity. This study investigated whether the routine use of methylene blue intraoperatively identified leaks to reduce the postoperative proportion of clinical leaks. This study retrospectively analyzed consecutive total gastrectomies performed from January 2007 to December 2014 in a university hospital setting by a general surgical group that exclusively used the methylene blue test. All surgeries were performed for gastric or junctional cancers (n = 198). All reconstructions (Roux-en Y esophagojejunostomy) were performed using a stapler. The methylene blue test was used in 108 cases (group 1) via a nasojejunal tube. No test was performed for the other 90 cases (group 2). Intraoperative leakage rate, postoperative clinical leakage rate, length of hospitalization, and mortality rate were the outcome measures. The intraoperative leakage rate was 7.4% in group 1. The postoperative clinical leakage rate was 8.6%. The postoperative clinical leakage rate was 3.7% in group 1 and 14.4% in group 2 (p = 0.007). There were no postoperative clinical leaks when an intraoperative leak led to concomitant intraoperative repair. The median length of hospital stay was 6 days in group 1 and 8 days in group 2 (p < 0.001). One death occurred in each group. No test-related complications were observed. The methylene blue test for esophagojejunostomy is a safe and reliable method for the assessment of anastomosis integrity, especially in cases with difficult esophagojejunostomic construction.

Nonintrusive diagnosis of premature ruptured amniotic membranes using a novel polymer.

PubMed

Bornstein, Jacob; Geva, Adam; Solt, Ido; Fait, Vladimir; Schoenfeld, Alex; Shoham, Hadar Kessary; Sobel, Jack

2006-08-01

This article describes the evaluation of the diagnostic efficacy of AL-SENSE panty-liner in detecting premature rupture of membranes (PROM). One hundred and three women attending the labor and delivery ward were enrolled into three groups: women presenting with a vaginal leak of fluid who had not yet been examined; women with overt PROM, and women with no fluid leak. The result of the AL-SENSE strip test was compared with the clinical diagnosis, which was based on direct visualization of the posterior vaginal fornix and cervix, crystallization, and nitrazine tests. AL-SENSE panty-liner test had a sensitivity of 100% and a specificity of 75% in detecting PROM, with an overall agreement of 82.35% between the AL-SENSE test result and the clinical diagnosis. AL-SENSE may be used as a reliable test to rule out PROM and as an effective device to diagnose PROM and differentiate it from urine leak and vulvovaginal candidiasis.

EVALUATION OF VOLUMETRIC LEAK DETECTION METHODS USED IN UNDERGROUND STORAGE TANKS

EPA Science Inventory

In the spring and summer of 1987, the United States Environmental Protection Agency (EPA) evaluated the performance of 25 commercially available volumetric test methods for the detection of small leaks in underground storage tanks containing gasoline. Performance was estimated by...