Flowguard Pulsation Dampers are gas-filled vessels installed on the pipeline. They store up and discharge part of the pump stroke volume by alternately compressing and expanding the gas cushion in synchronization with the motion of the pump. In actuality, these vessels work much like a filter in a power supply as it converts the ripple of a rectified sine wave into dc current.
The gas cushion is normally nitrogen gas and is separated from the process fluid by a flexible membrane (i.e. bladder, diaphragm or bellows). The flexible membrane prevents the nitrogen gas from being absorbed into the process fluid which means very little maintenance (if any) is required during standard operating conditions.
Generally, the application of a flowguard pulsation damper is based on one or more of the following criteria:
- Prevent potential pipe hammer/vibration
- Reduce the load on the pump itself
- Minimize or eliminate pulsations for the benefit of downstream instrumentation
- Minimize or eliminate pulsations as a dictate of process
Flowguard Suction Stabilizers can be sized to recover up to 95% of acceleration head losses and can easily make the difference where NPSH is concerned. Regardless, it is a parameter which every specifying engineer is obliged to check when applying a reciprocating PD pump.