2:55 · Technical explainer
Pulsation Dampener
See where dosing flow pulsation comes from and how a diaphragm dampener smooths the flow.
Silent animation · English text and on-screen subtitles · Full-screen viewing recommended on phones.
Understanding the illustration
This animation explains general principles. Construction, operating limits and settings vary by model; use the applicable manufacturer’s documentation for equipment selection and operation.
Read the English transcript
A dosing skid draws chemical from a tank and injects it into the process line.
The suction side has a calibration column and a Y-strainer.
One duty and one standby pump; a relief valve returns flow to the tank on overpressure.
A pulsation dampener sits at the pump outlet, followed by a gauge and a back pressure valve.
Chemical goes via the outlet valve to the injection point.
A diaphragm metering pump is reciprocating: a motor-driven push rod moves the diaphragm.
It delivers only on the discharge stroke, so outlet flow comes in pulses.
For a simplex pump, peak flow is about π times the average flow.
Pulsing flow causes pipe vibration, metering error and pressure spikes.
A common diaphragm dampener: gas chamber on top, liquid chamber below, a diaphragm between.
Nitrogen precharges the gas side; the liquid side joins the discharge line.
When flow is above average, the excess enters the liquid side and compresses the gas.
When flow is below average, the gas expands and pushes the stored liquid back.
The gas acts like a spring, so flow after the dampener stays close to average.
Without a dampener, pressure swings with every stroke and the pipe shakes.
With a dampener, pressure is steady, piping is quiet and dosing is more accurate.
Install it close to the pump outlet and precharge it with nitrogen as specified.
Check the precharge regularly. A dampener does not replace the BPV or relief valve.