Research on Gate Valve Internal Leakage Detection Based on Acoustic Emission Signal Processing

Gate valve is common equipment in the petrochemical industry. It often brings out internal leakage because of quality, operation, corrosion and other reasons, and has adverse influence on safety production, environment protection and energy conservation. This paper put forward the on-line detection method about the gate valve internal leakage detect problem on the basis of AE signal analysis. Firstly, introduced the structure of gate valve and main reasons of internal leakage, discovered the acoustic emission signal parameters of gate valve internal leakage, and derived the relation model between internal leakage and AE signal theoretically. Then, constructed internal leakage signal acquisition platform based on DN80 gate valve internal leakage simulation system. Finally, put forward gate valve gas internal leakage test, set the different pressure at different points on the conditions of different pressure valve of 0.2MPa, 0.4MPa and 0.6MPa, The experiment showed that gate valve internal leakage status can be displayed by the signal RMS value when the gate valve internal leakage AE signal is between 30kHz and 80kHz. The AE signal next to the gate valve downstream position is the strongest. Internal leakage of the valve exists if downstream signal was significantly greater than the upstream signal or the background noise. The AE signal strengthened while the pressure difference between upstream and downstream is increased.