Leak detection and location for gas pipelines using acoustic emission sensors

This paper presents an adaptive leak detection and location scheme for gas pipelines by using acoustic emission (AE) sensors. When gas being ejected from pipelines, an acoustic emission is produced at the leak hole and the acoustic vibration is transmitted along the pipeline. The acoustic movement can be picked up by AE sensors placed at either sides of a suspected leak on the outer surface of pipelines. The elastic wave signals carry the information of the gas leak source which reveals the occurrence and location of the gas leak. The time delay between the two elastic wave signals are estimated by an adaptive time delay estimator and used in combination with the sonic speed in gas pipelines and the space of the two sensors to locate the gas leakage. The experimental resuIts show that the length of the tested pipeline can be up to over 80 m at a time and the relative location error is around 1 %.