Acoustic Emission Application for Unapproachable Pipeline Drain Point Leakage Detection

摘要

The pipeline drain point which is at an unapproachable location is a problem to check a leakage by common techniques such as soap test and ultrasonic leak test. Acoustic emission is an advantageous technique to be applied for solution to this case. The sensitivity, acoustic attenuation, acoustic signal character, and background noise are the main factors considered in this chapter. The laboratory and field experiments were done for collection of AE signal. In laboratory, the leak rate was simulated by roughly loose an end cap of drain point for 300 and 600 main pipe diameter. The characteristics of acoustic signal emitted by leakage and background noise were revealed by time and frequency domain analysis. The experimental results showed that the minimum detectable atmosphere leak rate at 10 m far from a wideband AE sensor was 20 ml/s which has the frequency response at 100 kHz. The acoustic characters of drain leakage and field background noise are the benefits for development of a portable device of leak inspection in the field.