Experiment Study on Acoustic Emission Detection of Internal Leakage of Gas Ball Valves

Valve internal leakage experiment using acoustic emission (AE) method was conducted to build the relationship between AE signals and various detect location, pressure, leakage interval and valve size. Empirical formula for ball valve internal leakage was obtained based on AE amplitude. First, the (AE)ASL value and inner leakage rate of different pressure, valve size, failure mode and the damage degree were obtained by develop the small opening and sealing damaged failure models, which are two common failure modes in ball valve internal leakage. Stepwise regression and partial least square method were further applied. Results show that fitting formula of the average prediction error is less than 10% in certain conditions (valve fault type and pressure conditions), and is promising in rapidly predict valve internal leakage rate.