Application of Acoustic Spectral Analysis Technique for In-service Detection of Pump Diaphragm Failure

The main component of air-driven pumps are elastic diaphragms. These diaphragms are made from rubber or some other flexible material such as a thermoplastic elastomer. A method based on frequency analysis of the acoustic signal obtained from an air-driven pump during operation is described in this paper. A fully digital system for frequency analysis based on a personal computer was developed for practical implementation of this method. The system was tested under laboratory and in plant conditions. Two types of laboratory tests were performed: tests performed on diaphragm containing different types of artificial flaws and tests performed on different types of diaphragm. Three tests were performed under in plant conditions. The main goal of these tests were to demonstrate the ability of the system in early failure detection of the pump. The tests were performed under very high level of background noise and lasted between two days and two weeks in length. During this time the system performed acquisition and data processing at 10 seconds intervals. These tests have demonstrated that our system can indicate impending pump failure at least four hours before actual failure.