EVALUATION OF INTERNAL BUTTERFLY VALVE LEAKAGE BY ACOUSTIC EMISSION

Abstract

Internal leakage due to damage of the valve seal is one of the most common butterfly valve problems. When the valve operates for a long time, this often results in sealing as well as exposure to high temperature and pressure. This study applies the acoustic emission technique to detect internal butterfly valve failure since it can measure leakage at exceptionally low frequencies. The 4-inch butterfly valve has been used for the simulation of the pipe system in the experiment. Low-frequency sensors are employed to measure the signal generated by the valve leakage. The results of the experiment reveal that the butterfly valve's frequency range with a low-frequency transducer is 15-30 kHz. The AE signal characteristic is capable of analysing the waveform, power spectrum density (PSD), Fast Fourier transform (FFT) and continuous wavelet transform (CWT) for each leakage mode.
Keywords: Butterfly valve; acoustic emission; gas leakage; fast fourier transform (FFT); continuous
wavelet transform (CWT).

Description