The development of acoustic emission for leak detection and location in liquid-filled, buried pipelines

Acoustic Emission leak detection and location for liquid-filled, buried pipelines was studied using various leak sources and laboratory reference standards, These standards provided significant data that have contributed to the development of test procedures for generating two-phase flow and a better understanding of the leak mechanism.. Results are discussed for leak signal enhancement due to two-phase flow, leak orientation and the presence of backfill surrounding the pipe. Field studies were performed on buried pipes to demonstrate that small leaks (less than 0.1 gallons/hour or 0.1 mL/second) can be detected under the right:test conditions and that the location of these small leaks can be determined using a variety of location methods. Among the different location methods examined was:a location technique referred teas "tuned" linear location. In addition, a modification to the conventional Signal Difference location technique is discussed.