How to Replace a Metering Pump Diaphragm
Summary: Step-by-step diaphragm replacement for solenoid and mechanical metering pumps, with common mistakes to avoid.
The diaphragm is the most critical wear part. Replace it when flow drops, leakage appears or the rupture alarm trips.
Steps
- Stop, power off, close valves, relieve pressure
- Drain and rinse the pump head
- Remove head bolts and the old diaphragm
- Clean mating faces and install the new diaphragm (align marks)
- Tighten bolts evenly in a cross pattern, reconnect piping
Key Notes
- Inspect the new diaphragm for scratches
- Torque bolts in stages per the manual
- Run 10 minutes at low stroke after replacement
Order genuine diaphragm kits via products or after-sales.