Dosing pumps are low-volume pumps with controllable discharge rates that are used to inject additives or difficult-to-mix fluids into mixing, pumping, or batch/tank systems. Dosing pumps are usually made from plastic, thermoplastic, or stainless steel and feature mounting holes or accessories. Single and double diaphragm models are available. Some dosing pumps are designed to move abrasive materials, acids, adhesives, chemicals, concrete and grout, coolants, hazardous materials, liquid metal, or lubricants. Other devices are rated for combustible, corrosive, high viscosity, or high temperature media.
Dosing pumps are also used to move gasoline, diesel fuel, and oil; ground water, potable water, salt water, and wastewater; sewage, sludge, slurry and ash slurry; gas and air; powders, solids, and rendering wastes; and a variety of liquids and liquids with solids. Dosing pumps are available with many features and can move media either vertically or horizontally, depending on the direction of the pump stator and rotor assembly. Adjustable speed pumps can operate at speeds selected by an operator while continuous duty pumps maintain performance specifications at 100% duty cycle. Run dry capable pumps can operate without pumped fluid or external lubrication for an extended period of time. Self-priming pumps are designed to create and maintain a vacuum level that is sufficient to draw fluid into the inlet without external assistance.
Some dosing pumps include a control panel, battery backup, grinding mechanism, pressure gauge, level control device, thermal overload protection, or suction. Other dosing pumps are explosion-proof, corrosion resistant, reversible, plug-in, portable, close-coupled, hygienic, or sanitary. Non-clog pumps can move sticky or stringy materials. Pumps with a strainer or filter can collect solids. With frame-mounted devices, the pump end is mounted on a bearing frame that is coupled to the motor. Sealless, jacketed, belt driven, multi-stage, and wash down capable dosing pumps are also available. Important specifications for dosing pumps include maximum discharge flow, maximum discharge pressure, inlet size, discharge size, and media temperature. Power sources include alternating current (AC), direct current (DC), compressed air, gasoline, diesel fuel, hydraulic systems, natural gas, steam, water, and solar energy. Pumps that do not include a power source typically provide a drive shaft for connection to a motor. Manually powered pumps rely upon hand or foot power.
Dosing pumps are used in a variety of commercial, industrial, municipal, and maritime applications. Examples include agriculture and horticulture, dairy farms, breweries and distilleries, construction, food service and food processing, power generation, and oil and gas production. Dosing pumps are also used in the aerospace and defense, automotive, machine tool, mining, medical, pharmaceutical, semiconductor, and paper industries. Cryogenic pumps are rated for conditions where temperatures are low enough for gases to condense to become liquids or solids.