Pump Diagnostics

Pump problems vary over a large range depending on the type of pumps and the usage of the pumps. They can be classified in the following manner by the pump type and the service:

1. Positive-displacement pumps—reciprocating pumps problems can be classified into the following categories:
   
   
   • Compressor valve problems: plate valves, feather valves, concentric disk valves, relief valves
     
   • Piston and rod assembly: piston rings, cylinder chatter, cylinder cooling, piston-rod packing
     
   • Lubrication system
     
   
   
2. Positive displacement pumps—gear-type and roots-type problems can be classified into the following categories:
   
   
   • Rotor dynamic problems: vibration problems, gear problems or roots rotor problems, bearing and seal problems
     
   • Lubrication systems
     
   
   
3. Continuous flow pumps such as centrifugal pumps problems can be classified into the following categories:
   
   
   • Cavitation
     
   • Capacity flow
     
   • Motor overload
     
   • Impeller
     
   • Bearings and seals
     
   • Lubrication systems
     

Table below about classifies different types of centrifugal pump-related problems, their possible causes, and corrective actions that can be taken to solve some of the more common issues. These problems in the table are classified into three major categories for these type of pumps:

1. Cavitation
2. Capacity flow
3. Motor overload

The use of vibration monitoring to diagnose pump and compressor problems is discussed at the end of the subsection on compressor problems.

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