Vibration-based diagnosis for ageing management of rotating machinery: A summary of cases

Availability of rotating machinery used in power plants and other processing industries is very important for overall production. To enhance this availability, vibration-based condition monitoring is usually used. Vibration-based condition monitoring is considered to be mature enough to predict the occurrence of faults in rotating machinery so that remedial action can be well-planned and maintenance works for all kinds of machinery can be completed in one shutdown. However, if the occurrence of faults/failure is frequent and related to the ageing factor, it would definitely affect the overall performance of plants even though vibration-based condition monitoring would detect faults well in advance. For such cases, it has been observed that either in-situ dynamic characterisation by modal testing, or Operation Deflection Shape (ODS) analysis, or both tests on in-situ rotating machinery be the best option to identify the root causes and resolve the problems. Examples of such cases are summarised here.