Chemical Dosing Pumps (Metering Pumps)

Chemical dosing pumps, explained

A chemical dosing pump, also called a metering pump, injects a small, controlled amount of chemical into a water line: chlorine for disinfection, antiscalant ahead of a reverse osmosis membrane, acid or alkali for pH correction, coagulants and process chemicals in treatment plants. The pumps on this page are solenoid diaphragm pumps: an electromagnetic drive flexes a chemical-resistant diaphragm, and each stroke moves a fixed shot of chemical through check valves. A basic dosing setup is the pump, a chemical tank, suction and delivery tubing, and an injection valve at the point where the chemical enters the line. We supply the pumps and injection valves; we do not build engineered dosing skids or supply the dosing chemicals themselves, and we will say so plainly if your project needs more than a pump. If you are replacing a pump, match the model code on the one coming out. If you are specifying from scratch, send us your duty details and we will recommend a model or tell you honestly that the range does not cover it.

The range: Injecta solenoid dosing pumps, made in Italy

Every dosing pump we sell is an Injecta electromagnetic solenoid pump, and each product page carries the full specification, flow and pressure figures, and pricing for that model.

• Manual constant-flow pumps: Olimpia OL.BP, in mains and low-voltage 24-48 VAC versions, and Hydra HY.BX. Set the dose on the front-panel knob and the pump holds it.
• Proportional pumps: Athena AT-AM2 and Injecta AT-AM3, which pace their dosing to a water meter pulse signal or an analogue input, per each product page.
• pH and ORP controlled: Athena AT-PR2, a digital pump that doses against a pH or ORP reading (probes optional, per its product page).
• Air treatment: Athena AT-AT6, a dosing pump with an atomising nebuliser for spraying treatment chemical into air handling systems.
• Injection valves: PVC-bodied valves with FPM or EPDM seals, and a PVDF valve for aggressive chemistry, all 4x6mm.

Chasing a model that is not here, a higher flow rate, or spare parts for an Injecta pump you already run? Contact us and we will quote it, along with the honest answer if we cannot help.

Manual, proportional or pH controlled: choosing a control mode

Control mode matters more than any other line on the spec sheet, because it decides how the pump keeps dose matched to demand. A manual pump doses at the constant rate you set on the knob, which suits steady flows and simple duties. A proportional pump takes a signal from a pulse water meter or an analogue instrument and doses in step with actual flow, so the dose per litre stays constant as flow changes. A pH or ORP controlled pump doses against a live probe reading to hold a setpoint, which is how chlorine residual and pH correction duties are usually run. If you have been trying to dose a variable flow with a manual pump, that mismatch, not the pump, is usually the problem. Tell us what the pump needs to respond to and we will tell you which control mode covers it.

Chlorine dosing and chemical compatibility

The duties these pumps are built for, per their product pages, include water and wastewater treatment, chlorine dosing, swimming pools, cooling towers, boilers and plant nurseries. The wetted materials are the reason: PVDF and PVDF-PVC pump heads, PTFE diaphragms and ceramic ball check valves, chosen by the manufacturer for compatibility with a wide span of treatment chemicals. Injection valve seals are picked to the chemical: EPDM seals for caustic duty and FPM seals as the standard option, with a PVDF-bodied valve for the most aggressive service, per the valve product pages. Chemical compatibility is always confirmed against the specific chemical and concentration you are dosing, so tell us what is in the tank when you order and we will flag anything that does not suit the pump head or seals. We do not supply the dosing chemicals themselves.

Injection valves, tubing and spares

An injection valve is the small non-return fitting at the point of injection: it connects the delivery tubing to the line, stops backflow, and holds a defined back pressure so the pump doses cleanly. The three valves in this range fit any dosing pump running 4x6mm tubing, not just Injecta pumps. The pumps themselves ship with an installation kit, per each product page, and replacement diaphragms, foot valves and other Injecta spares can be quoted on request. We do not stock bulk tubing runs, so for long delivery lines we will point you to a supplier who does. If a valve or spare you need is not listed, contact us with the pump model and we will tell you plainly whether we can source it.

Supply for Australian industry

MDC Water has supplied membranes and water treatment components to defence and government facilities, universities, food and drink production, and energy utilities across Australia and overseas since 1998. In-stock items dispatch next business day, and pricing is on every product page so you can compare models before you order. We handle formal quotes, tax invoices and vendor onboarding paperwork, and we quote freight to site including regional and remote addresses. Dosing rarely travels alone: antiscalant and chemical injection duties usually sit ahead of a reverse osmosis membrane train, boiler feed treatment pairs dosing with water softeners, and the inline instruments range carries monitors for the water you are treating.