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4.7.2.2 Pressurized Piping Leak Detection (PPLD)

 

Leak detection equipment (e.g. mechanical and electronic line leak detectors) for pressurized piping systems must be able to detect leaks in piping of 3.0 GPH or greater at 10 PSI (pounds per square inch) within one hour after a dispensing cycle. All leak detection methods must be able to detect a leak of 3.0 GPH from pressurized piping with a probability of detection (Pd) of 95%. This means that if a 3.0 GPH leak existed in a piping system then the detection method would have to positively identify the leak 95 out of 100 times.

 

Likewise, leak detection methods are permitted a probability of false alarm (Pfa) for a 3.0 GPH leak of 5%. This means that if a 3.0 GPH leak existed in a piping system then the detection method would be allowed to falsely identify the piping system as being tight (no leak) 5 out of 100 times.

 

Third-party testing results reports will specify whether leak detection equipment and/or a method meet the above Pd and Pfa requirements, and under what conditions (e.g. length and diameter of the piping, as well as the type of piping such as steel, FRP, or flexible or semi-rigid plastic).