Structural Health Monitoring and Safety Evaluation of Pressure Vessel by the Use of Acoustic Emission Technology

Abstract

Acoustic emission technique is a widely used nondestructive method for pressure vessel testing and monitoring. Since it was applied to pressure vessels in the early 1980s in China, more than 2000 fields PVs has been tested and monitored by China special equipment inspection and research institute. Based on the monitoring results, the acoustic emission sources that could be encountered during monitoring of pressure vessels are presented, which are crack initiation and propagation, weld defects cracking, residual stress releasing, oxide scales peeling off, structural friction, leakage, electronic noise, wind blasting and et al. The characteristics of each acoustic emission source are summarized respectively. The safety evaluation method based on AE monitoring for pressure vessel is given. The evaluation of acoustic emission sources is according to the activity and intensity of acoustic emission source. Acoustic emission source activities are divided into 4 levels including in weak, medium, strong and very strong. Acoustic emission source intensities are divided into 3 levels including in low, medium and high. The final evaluation of acoustic emission sources are given in 4 levels by colligating activity level and intensity level of acoustic emission sources. In addition, two typical application of acoustic emission technique on PV monitoring are introduced.