The sewage pumps used in the building include submersible sewage pumps, submerged sewage pumps, vertical sewage pumps and horizontal sewage pumps. Since the general site in the building is small and the drainage volume is not large, the submersible sewage pump and the submerged sewage pump can be used in priority for the drainage pump. The submersible sewage pump is generally used in important places; the vertical sewage pump and the horizontal sewage pump require isolation It is seldom used in construction because it has earthquake foundation, self-irrigation water absorption, and takes up a certain area.

The flow rate of the sewage pump should be selected according to the second flow rate of the living drainage design; when the drainage volume is adjusted, it can be selected according to the maximum hourly flow rate of the living drainage. The flow rate of the drainage pump in the fire elevator sump is not less than 10L/s.

After the lift of the sewage pump is calculated and determined according to the lifting height and the pipe loss, a certain free head is added. The free head should be 0.02～0.03MPa. The flow velocity of the suction pipe and outlet pipe of the drainage pump should not be less than 0.7m/s, and should not be greater than 2.0m/s.

In public buildings, a standby pump should be set up with each living drainage collection basin as a unit, and should be operated alternately at ordinary times. If there are two or more drainage pumps for the drainage of the basement, equipment room, and garage, the equipment does not need to be used. When the sump can not be equipped with an accident drain, the pump should have an uninterrupted power supply; when the drain and inlet pipe can be closed, the uninterrupted power supply may not be provided, but an alarm device should be installed.

When lifting sewage and wastewater with large impurities, the outlet pipes of submersible sewage pumps in different sumps should not be combined for discharge; when lifting general wastewater, the outlet pipes of submersible sewage pumps of different sumps can be combined and discharged according to the actual situation.

When two or more water pumps share the same outlet pipe, a valve and a check valve should be installed on the outlet pipe of each pump. When a single water pump discharge may cause backflow, a check valve should be provided. It is not allowed to merge the pressure drainage port with the gravity drainage pipe in the building.

When the submersible sewage pump contains large debris, the submersible sewage pump should be equipped with a crushing device; when the sewage contains more fibrous materials, a large channel submersible sewage pump should be used.

When the submersible sewage pump motor power is greater than or equal to 7.5kW or the water outlet pipe diameter is greater than or equal to DN100, the water pump fixed autocoupling device can be used; when the submersible sewage pump motor power is less than 7.5kW or the water outlet pipe diameter is less than DN100, soft Pipe mobile installation. When a submersible sewage pump is used to drain the sewage collection tank, a fixed auto-coupling device for the pump should be installed to facilitate the maintenance of the pump.

The sewage pump should be able to start and stop automatically and manually on site. Multiple pumps can be operated alternately in parallel, or put into operation in sections.