Metering Pumps (Dosing Pumps)

A metering pump (dosing pump) is a positive-displacement pump that delivers a set volume per stroke. Output is adjusted by changing stroke length or stroke frequency, which makes it the standard choice for chemical dosing in water treatment, chemical processing, power, pharmaceutical and food plants.

By drive type there are solenoid diaphragm, mechanical diaphragm, hydraulic diaphragm and plunger metering pumps. Solenoid pumps are compact and suit low flows; mechanical diaphragm pumps cover medium flows at low to moderate pressure; hydraulic diaphragm pumps combine higher pressure with leak-free diaphragm sealing; plunger pumps reach the highest pressures but need attention to packing seals.

Start selection from the maximum dosing rate and system back-pressure with a safety margin, then choose head and diaphragm materials for the chemical, its viscosity and temperature, and finally the control mode (manual, pulse, 4–20 mA or fieldbus). Weilan distributes several metering pump brands and can recommend models and quote for your duty.