Some pumping jobs are about volume; dosing is about precision. A dosing pump injects an exact, measured amount of liquid, almost always a chemical, into a process stream, tank or pipeline, and keeps doing it accurately whatever the pressure or temperature does. Water treatment, chemical processing, food and beverage, pharmaceutical production and pool maintenance all depend on getting that dose right.
We supply dosing pumps from ProMinent, one of the world’s leading names in dosing technology, and can source other makes for a specific requirement. The ranges are below, or call +44 1332 913500 for help choosing.
A dosing pump, also called a metering pump or chemical injection pump, delivers a controlled volume of liquid per stroke or per unit of time. Where a transfer pump simply moves bulk liquid from one place to another, a dosing pump’s whole purpose is accuracy: the right amount of chemical, at the right rate, regardless of what the rest of the system is doing.
They are positive displacement by design. Each stroke shifts a fixed, known volume, so the dose is set by adjusting stroke length, stroke speed or both. That gives fine control over the delivered rate, across a range that spans very small trim doses up to substantial industrial feed rates depending on the model.
Mechanical dosing pumps, also known as mechanically actuated diaphragm pumps, use a motor-driven cam or eccentric to push the diaphragm to and fro. The dose is set by stroke length, usually on a manual knob, and stroke frequency. Robust and simple, a mechanical dosing pump suits steady-state duties where the rate rarely changes, which is why it is so common in water treatment, cooling towers, boiler houses and pool plant.
Electronic solenoid dosing pumps drive the diaphragm with an electromagnetic solenoid and control the dose electronically. That allows remote adjustment, proportional dosing tied to a signal such as 4 to 20 mA or a flow-meter pulse, and integration with SCADA or BMS. They suit duties where the rate has to respond to changing conditions: pH correction, residual disinfection, proportional chemical feed.
Motor-driven diaphragm dosing pumps step up to higher flows and pressures than a solenoid can manage, using a geared motor through a mechanical linkage with electronic stroke control, for industrial water treatment, chemical processing and high-pressure injection.
We supply three ProMinent ranges. Most duties land in one of them.
Not sure which fits? Send us the dose rate, the back-pressure and the chemical, and we will confirm the model and the wetted materials. Call +44 1332 913500 or request a quote.
Since the great majority of dosing pumps inject chemicals, the term chemical dosing pump is used interchangeably with dosing pump. The chemicals span the harmless to the savage, from sodium hypochlorite for pool disinfection to concentrated acids, alkalis, polymers and oxidisers in industrial treatment.
That makes compatibility critical. Every wetted part, the diaphragm, valve balls, valve seats, seals and pump head, has to resist the dosed liquid. Common materials are polypropylene, PVDF, PVC, PTFE and stainless steel. Use our chemical compatibility calculator for a first check, and we can confirm the right combination for your fluid against the manufacturer’s resistance data.
Where the chemical is abrasive, prone to off-gassing or shear-sensitive and a diaphragm pump struggles, a peristaltic pump is often the better answer.
A dosing pump on its own rarely solves the problem. We supply the surrounding equipment so the installation arrives as a working system.
Tell us the chemical, the dose rate and the process pressure and we will quote the whole system. Request a quote or call +44 1332 913500.
Three things size a dosing pump: the dose rate at the duty point in litres per hour, the discharge pressure it works against (back-pressure plus any static head), and the chemical being dosed, which decides the wetted-part materials. Beyond that, consider whether the rate is fixed or variable, whether the pump must accept a control signal, whether ATEX rating is needed for a hazardous area, and the power supply.
As experienced dosing pump suppliers we work mainly with ProMinent and source other makes where a job calls for it. Tell us the application on +44 1332 913500 and we will recommend the right model.
Got a question about dosing pumps? Find the answers to our most common questions here.
Can’t find your answer? Get in touch with our team.
A dosing pump injects precise, measured volumes of liquid, usually a chemical, into a process stream, tank or pipeline. Common applications include water and wastewater treatment, swimming pool chemical dosing, cooling tower treatment, food and beverage processing, and pharmaceutical manufacturing. Any process that requires a controlled, repeatable dose of liquid is a candidate for a dosing pump.
Sizing requires three inputs: the dose rate you need, the discharge pressure the pump must work against (system back-pressure plus static head), and the chemical being dosed, which determines material selection. The pump’s maximum capacity should sit comfortably above the required dose rate so it is not running permanently at full stroke. Send us your application details and we will specify the right model.
Price is driven by the flow and pressure rating, the control type and the wetted materials. A simple mechanical or solenoid pump for a fixed low-rate duty sits at the bottom of the range; an electronically controlled pump with PVDF or PTFE wetted parts and a control signal input costs more; a motor-driven pump for high pressure more again. Send us the duty and we will quote the actual model rather than a range.
The whole system. Tanks, bunds, suction lances, injection valves, calibration pots, back-pressure and relief valves, pulsation dampeners, controllers, sensors, tubing and fittings, all in materials matched to your chemical. Most of the dosing installations that fail do so because of the parts around the pump rather than the pump itself.
Yes, with the right specification. Hypochlorite off-gasses, and the gas bubble collects in the pump head and stops it dosing even though the motor keeps running, which is the most common complaint on pool and water treatment installations. The fix is a self-degassing pump head or a degassing valve, plus compatible wetted materials. Tell us the chemical when you enquire and we will specify accordingly.
