Chemical Dosing Pumps

A chemical dosing pump is a positive-displacement pump designed to inject precise small volumes of chemical into a process stream. Unlike centrifugal pumps that move bulk fluid, dosing pumps deliver a known volume per stroke — making them suited to applications where dosing accuracy matters: water treatment chlorination, RO anti-scalant injection, pH control, agricultural fertilisation and industrial process chemistry.

A metering pump is a positive-displacement pump that delivers a fixed, repeatable volume per stroke. Diaphragm metering pumps use a flexing diaphragm driven by a solenoid or motor; each stroke pushes a precise fluid volume through check valves into the discharge line. Peristaltic metering pumps use rollers compressing a tube to displace fluid. Flow rate is controlled by adjusting stroke length, stroke frequency or both — making metering pumps tunable to wide flow ranges from a single unit.

Chemical compatibility depends on the dosing pump's wetted parts material. Standard PVC and polypropylene wetted parts handle most common water treatment chemicals — sodium hypochlorite, alum, soda ash, anti-scalant. PVDF and PTFE wetted parts are required for concentrated acids (sulphuric, hydrochloric), strong caustics, and aggressive oxidisers. Always check the chemical compatibility chart for the specific pump model before specifying — the wrong wetted parts material will fail rapidly under aggressive chemistry.

Solenoid diaphragm pumps use an electromagnetic solenoid to actuate the diaphragm in pulsed strokes — compact, lower-cost and suited to lower-flow applications up to roughly 20 LPH. Motor-driven diaphragm pumps use an electric motor and mechanical drivetrain to actuate the diaphragm continuously — smoother dosing, higher flow rates, and higher pressure ratings. Solenoid pumps suit basic dosing on low-pressure systems; motor-driven pumps suit higher-flow, higher-pressure or precision-critical dosing.