Waste water pump

Waste water pumps transport heavily contaminated water which often contains solid particles of various organic, inorganic and mineral origin. Single-stage designs are preferable. Waste water pumps are generally not self-priming. They are completely submerged in the fluid handled. Wear-resistant mechanical seals are used as a shaft seal.

Typical applications are those of the food processing, construction, pulp and paper, sugar, and metal industries (e. g. metal electrolysis) as well as mining and water extraction (e. g. cooling water, seawater desalination). A distinction is made between municipal and industrial waste water pumps as the requirements differ considerably. Municipal waste water pumps, also referred to as sewage pumps, typically transport the following fluids: raw sewage (e. g. waste water, sewage, see Sewage pump),  mechanically treated waste water from treatment tanks, sludge (e. g. activated, raw, digested and return activated sludge) as well as stormwater.

For industrial waste water pumps the selection of suitable materials is crucial as industrial waste water can be highly aggressive or abrasive (see Abrasion). The pump casing can be especially fitted with casing wear rings or wear plates which are made of particularly wear-resistant materials and can be easily replaced.

Waste water pumps can be designed for either wet well or dry installation. Waste water pumps for wet well installation are also referred to as submersible motor pumps. See Figs. 2, 3, 5 Waste water pump

Waste water pumps can also be installed as horizontal pumps (see Figs. 1, 4, 6 Waste water pump) or vertical pumps (e. g. underfloor installation). See Fig.2 Vertical shaft submersible pump

The counterpart of this pump is the clean water pump. 

The type of impeller used depends on the fluid handled:

• Channel impeller with one, two or three channels (either closed or open)
  See Figs. 1, 2 Waste water pump
• Open single-channel and diagonal impeller
  See Fig. 4 Waste water pump
• Free-flow impeller (see Torque flow pump)
  See Fig. 3 Waste water pump