Pump Types

Dosing pumps can operate based on the principles of dynamic pumps or positive displacement pumps depending on the design. Dynamic pumps produce a variable flow suited for generating high flow rates with low viscosity fluids, while positive displacement pumps produce a constant flow suited for producing high pressures (and low flow rates) with high viscosity fluids. Most dosing pumps are positive displacement pumps, which provide steady, low flow for a variety of types of media. Look to Engineering360's Pump Types page for a complete guide to the different types of pumps available.

Specifications

Matching a pump to the application requirements requires an analysis of manufacturer specifications. Typical specifications to consider when selecting dosing pumps are flowrate, pump head, pressure, horsepower, power rating, and operating temperature. More information on these specifications and how to interpret them can be found in Engineering360's Pump Flow page.

One important specification that is largely specific to dosing pumps is accuracy. Accuracy describes how close a volume of pumped fluid is to the exact desired value. Pumps with higher accuracy will pump measured volumes of fluid with more precision and repeatability. Accuracy is given in a +/- value or % variability.

Materials

The base material of a dosing pump is important to consider, as it affects the type of media that can be handled effectively. System fluids may be abrasive, acidic, caustic, tacky, very hot, very cold, or otherwise hazardous. Base materials such as cast iron, plastic, and stainless steel possess different advantages for handling these various characteristics.

• Plastics are the least expensive base materials, and provide excellent corrosion resistance and protection from a broad range of chemicals.
• Stainless steel alloys provide excellent protection against various chemicals and rust corrosion, and have higher pressure ratings than most plastics.
• Cast iron provides excellent strength and abrasion resistance, with high pressure ratings.

For more information on materials and other pump features, visit Engineering360's Pump Features page.

Applications

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.

Image Credit:

Mahr Metering Systems Corporation | Waston Marlow Pumps Group