Chemical pumps are used to move chemicals and chemical slurries, and are designed to be resistant to corrosion and abrasion from industrial liquids such as fuel, paint, bleach, solvents, etc. They are able to handle fluids of varying viscosity and can also be used as metering pumps to provide flow measurement and control where precise volumes of chemicals need to be delivered.
Nearly all pumps can be designed as a chemical pump, with them being either a centrifugal or positive displacement type pump depending on the requirements of a specific application.
Primary specifications that will help determine which type of pump to select are:
- Flow rate
- Operating temperature
Materials used in the construction of the pump will also help in the selection process, as this will affect the type of fluid that it can handle. Plastics and thermoplastics are the cheapest materials and provide excellent corrosion resistance from acids and various chemicals; stainless steel alloys provide protection against chemical and rust corrosion, and have higher pressure ratings than most plastics; and cast iron has excellent strength and abrasion resistance, with high pressure ratings.
ANSI process pumps are the most common type of centrifugal pump used as a chemical pump. There are also many types of positive displacement pumps used for chemical pumps – such as screw, AODD, double diaphragm and plunger pumps – as they can move the fluid at high pressures.