Description:

Reciprocating pumps (comprising of piston, plunger and diaphragm pumps) are commonly used pumps in industrial process. These type of positive displacement pumps achieve high discharge pressure while providing a nearly constant flow rate over a wide range of pressure and fluid viscosity. The reciprocating motion of the piston, plunger or membrane acting in combination with the check valve in the pump fluid end on the suction and discharge (pump valves) create the high-pressure delivery of fluid by the pump. Proper operation of the pump valves is key to the reciprocating pump meeting the application requirements.

​

The pump valves are moving components and like any other moving components they will wear over time and can fail if not serviced properly. Also, the valve selection may not be appropriate for a particular application if the process conditions or fluid properties have changed over time. A pump valve that is not operating properly due to wear or improper selection can result in loss of capacity and performance of the pump. A less understood consequence of faulty valve operation is the generation of significant pressure pulsations that can cause excessive vibration on the pump, piping and surrounding structure.

​

The goal of this case study is to present experience with field testing reciprocating pump facilities where the root cause of piping vibrations was faulty pump valves. A case study will be presented demonstrating advanced instrumentation and measurement techniques to evaluate pump valve operation. Field measurements of pulsation spectrum analysis and analysis of valve closing angle in relation to plunger position for successfully diagnosis a faulty valve as well as properly operating valves will be described.