Leak detection

Figure 4. Principle for radiotracer leak detection in pipelines.

Thermographic sensor Leak detection Leak location... 

The next step is to apply a number of loss control credit factors such as process control (emergency power, cooling, explosion control, emergency shutdown, computer control, inert gas, operating procedures, reactive chemical reviews), material isolation (remote control valves, blowdown, drainage, interlocks) and fire protection (leak detection, buried tanks, fire water supply, sprinkler systems, water curtains, foam, cable protection). The credit factors are combined and appHed to the fire and explosion index value to result in a net index. 

Superfluid helium can pass easily through openings so small that they caimot be detected by conventional leak detection methods. Such leaks, permeable only to helium II, are called supedeaks. They can be a source of fmstrating difficulties in the constmction of apparatus for use with helium II. 

Different combinations of stable xenon isotopes have been sealed into each of the fuel elements in fission reactors as tags so that should one of the elements later develop a leak, it could be identified by analyzing the xenon isotope pattern in the reactor s cover gas (4). Historically, the sensitive helium mass spectrometer devices for leak detection were developed as a cmcial part of building the gas-diffusion plant for uranium isotope separation at Oak Ridge, Tennessee (129), and heHum leak detection equipment is stiU an essential tool ia auclear technology (see Diffusion separation methods). 

Out-of-tank leak detection ground penetrating radar and inventory methods... 

Le kDetection. Leak detection methods may be subclassified according to whether or not they are on the tank. On-tank leak detection systems operate immediately upon leakage. 

On-Tank Teak Detection Systems. Tanks having leak detection bottoms have a means of directing any leaks to the outside of the tank perimeter where these can be visuaUy observed. Before any significant contamination can occur, the leaks are discovered and the tank taken out of service to address the leak. 

Use of Liners. The use of impermeable liners and membranes, often called release prevention barriers (RPBs) under tanks, may be the most effective leak detection and prevention method. On new tanks, it is relatively easy to install these systems, and large numbers of tanks are being built with this type of system in the 1990s. For existing tanks, however, it would be very costiy if not impractical to install liners. For existing tanks, the combination of other methods as well as an effective inspection program can be more effective as a substitute for a release prevention barrier. 

There are usually several reactors hnked to a single catch tank. To ensure that rupture of a disk on one reac tor does not affect the others, each reactor is fitted with a double-rupture-disk assembly. The use of double rupture disks in this apphcation requires installation of a leak detection device in the space between the two disks, which... 

Detecting Leaks Small leaks are difficult to detect. The USEPA and American Petroleum Institute standard for nonlealdng underground tanks is 0.05 gaUh (3.15 cmVmin), above which a tank is considered to be leaking. Leak detection measurements can be influenced by many factors, making it difficult to detect small leaks. 

Use rupture disks alone or in combination with safety valves with appropriate rupture disk leak detection... 

API Publ 334, A Guide to Leak Detection for Aboveground Storage Tanks, September 1995. 

Does the Toller use a primary ozone depleting compound (ODC, for example, a CFC or 1,1,1, -trichloroethane) m their process Are ODC management practices followed (for example no uncontrolled releases of ODCs, installation of capture and recycle equipment, leak detection and repair, use of well trained personnel) ... 

Signiflcanl new material on welding, electrii al liusign, aiui corrosion has been added It also covers liytirostatic testing, pipeline drying lit uids, [nimps, valves, leak detection and pipeline ni.iinten.7n( e... 

Immediately after the running test, any compressor intended for toxic, hazardous, flammable, or hydrogen-rich service should be gas tested with an inert gas to the maximum seal design pressure. The test is held at least 30 minutes and the casing and its joints checked for leaks, using a soap bubble method or other suitable means for leak detection. When no leaks are detected, the compressor will be considered acceptable. 

Detector tubes/pumps are screening instruments which may be used to measure hundreds of organic and inorganic gases and vapors or for leak detection. Some aerosols can also be determined. Detector tubes of a given brand are to be used only with a pump of the same brand. 

M7 Improved Housekeeping, Training, Inventory Control (e.g., alter maintenance frequency institute leak detection program improved inventory control institute training program on waste minimization)... 

Leak Detection/Repair. Partial or Complete Removal... 

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