A pulsation dampener is a small chamber fitted to the pump discharge that absorbs the pressure peaks of a pump and releases them again between strokes. The result is a smoother flow and less stress on the pump and the pipework.
Why pulsation is a problem
Piston, plunger, diaphragm, AODD and metering pumps deliver fluid in pulses. Without damping, this causes:
- Pressure spikes and pipe vibration, which loosen fittings and damage instruments.
- Inaccurate flow readings and uneven dosing.
- Faster wear of valves, diaphragms and seals.
- Noise and fatigue failures in the pipework.
How a dampener works
Most dampeners have a chamber divided by a flexible diaphragm or bladder, with gas (usually nitrogen) on one side. When a pressure pulse arrives, the gas compresses and takes in some of the fluid. As the pressure falls, the gas expands and pushes the fluid back out into the line.
Where to fit it
- As close to the pump discharge as practical, ideally directly on the discharge line.
- On the suction side as well, for long suction lines or when the pump is starved.
- With an isolation valve and a bleed so it can be checked and recharged safely.
Setting it up
- Size the dampener for the pump type, stroke volume and operating pressure. Ask the manufacturer for the correct size.
- Set the gas pre-charge as the manufacturer specifies, commonly a percentage of the line pressure. Never charge it while the line is under pressure.
- Choose the diaphragm material to suit the fluid, just as you would for the pump.
- Check the pre-charge regularly. A dampener that has lost its charge no longer works.
When you need one
Almost always with metering pumps that feed precise doses, with piston and plunger pumps, and with AODD pumps on long or high-pressure lines. See the related guides on piston and plunger pumps, choosing a dosing pump and our AODD pumps.
Power Energy Gulf can supply pumps with the right accessories for your duty. Contact us with your fluid, flow and pressure details and we will recommend a suitable pump.
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