The material of a pump in contact with the medium must be suitable for its application. Numerous common materials are used for the components of pumps that come into contact with the media. They can be made in various materials and pure metals, for example:
- Cast iron
- Bronze
- Stainless steel
- Duplex
- Hastelloy
- Titanium
In addition, many pumps are offered whose parts that come into contact with the medium are made of plastics, for example:
In addition, pumps with components that come into contact with the medium made of ceramic or composite materials are also available.
The choice of material always depends on the medium to be pumped. Grey cast iron or stainless steels can withstand many liquids. However, if glycolic acid is being pumped, for example, operators have to switch to titanium. Hastelloy must be used when pumped media would lead to pitting, for example when pumping strongly oxidizing liquids such as hydrochloric acid, sulfuric acid or chlorides. In many cases, however,
plastic pumps can also pump critical media. PFA-lined pumps, for example, are often suitable for pumping corrosive media, especially in fine chemical and basic chemical processes, because the material does not corrode.
The pump housing must also take into account the operating conditions. If, for example, aggressive cleaning agents are used for cleaning, the pump housing must be able to withstand such agents just as well as the surfaces of other system components. The housing of plastic pumps is therefore also usually made of metal.
