It’s common knowledge that when a pump has internal wear, the performance of it suffers. The flow is reduced and the efficiency drops drastically. The power though is effected by internal wear of pumps. In the most extreme cases, if the impeller is completely worn out, there will be no flow or power. Though in most cases the tight clearance parts, like wear rings and bushings, are the first to go.
Periodic testing of the pumps will show how the performance is working. The power data can tell the difference between internal wear. For example if the wear ring clearances have worn out or the impeller is deteriorating. Vibration analysis along with a performance audit can help to determine if repair is needed or work can continue on.
For more about Power and Efficiency of worn out pumps visit Pumps and Systems HERE