A

When it comes to sewage & wastewater transfer there are usually 3 choices - to have the pumps Immersed or submerged within a pit, Surface Mount units and prime liquid from tanks or have the pumps below or adjacent to a tank, meaning they are flooded with fluid.

If pumps are surface mounted in such installations, they will need to be self-priming. This means they are designed to evacuate air from the suction line and prime fluid. There are a variety of pump designs which are self-priming as standard such as progressing cavity, peristaltic, and AODD pumps. Other designs such as centrifugal must be specified at design stage as such.

The installation type can affect the amount of civil work required. Having a pump which is surface mounted or installed adjacent or below a tank can involve a bigger initial outlay in pump installation, however long-term maintenance costs can be reduced. Similarly having a pump head submerged within a tank, but the motor located outside the fluid will reduce maintenance intervals but require a crane for removal adding to servicing costs...

Thought also needs to be given to space available which can eliminate surface mounted pumps as options in particular when wastewater from car parks or other areas requires pumping as often the only space available is the chamber itself.