An Acoustic-Based Approach for Condition Monitoring of Pipes

Polyvinyl chloride pipes are extensively used in municipal sewer systems. As the sewer system ages, polyvinyl chloride pipes become prone to developing cracks that can release toxic effluents into the environment. Traditionally, utility operators pass a close circuit television camera mounted on a guided vehicle through the pipe to monitor the defects. The video is observed by a trained operator who records the condition of the pipe. This arrangement has two major limitations. First, it is expensive due to complex set up. Second, if a pipe is blocked the guided vehicle cannot pass through its entire length. A more economical and robust system is needed that can reliably detect cracks in sewer pipes. The present study proposes an approach to detect cracks in a pipe by measuring attenuation of a propagating acoustic signal. The preliminary results from laboratory test setup are presented and discussed. As the results show, the proposed approach is capable of identifying defects in a cracked pipe compared to a pipe that has no crack