Smart portable noninvasive instrument for detection of internal air leakage of a valve using acoustic emission signals

Acoustic emission (AE) can be used to detect and determine the internal leakage rate through a valve in many applications. However, a general AE data acquisition system is expensive and bulky. This paper presents a novel low-cost instrument based on microcontroller and a novel theoretical model based on AE technique to predict the leakage rate. The system is an embedded system instead of a general PC-based data acquisition. AERMS parameter is used to infer the leakage rate, and the effects of various process variables on the model are also studied. The experimental results have shown that the instrument is capable of detecting possible valve leakage encountered in online operation. With its portability, ease of use and compactness, the proposed system provides faster and low cost valve leakage detection.

Research highlights
► We develop mathematical model and a portable instrument based on microcontroller.
► The model is derived to predict leakage rate of valve and applied to the instrument.
► Valve size has the most significant effect on the leakage rate.
► The instrument returns a volumetric leakage rate in within 3 s after measuring.
► Our instrument has user-friendly interfacing, good sensitivity and high reliability.