Advances in Acoustic Methods for Locating Leaks in Plastic Pipe and Trunk Mains

Acoustic devices are the most common type of equipment used to locate leaks in municipal water pipes. These include simple listening devices such as ground microphones and listening sticks. Acoustic devices also include leak noise correlators, which were first developed more than two decades ago and have significantly improved the accuracy of locating leaks. It is generally accepted that the effectiveness of existing correlators is limited on plastic pipe and larger diameter trunk mains. This paper will go over the physics of leak noise in plastic and larger diameter trunk mains, sound. The frequency and wavelength of the sound waves will be reviewed in relation to the field procedures required to measure the physical acoustic waves of leaks on plastic pipe and trunk mains. Case studies will then be provided to illustrate best practices for conducting leak detection on plastic pipe and trunk mains. Leak studies of actual leaks on both plastic pipes and trunk mains will be reviewed to demonstrate the field methods that were successfully implemented, as well as the leak noise frequencies of the successful detects.