Drainage pumps used in buildings include submersible sewage pumps, submerged drainage pumps, vertical sewage pumps and horizontal sewage pumps. Because the general site in the building is small and the drainage volume is not large, the drainage pump can preferably use the submersible sewage pump and the submerged drainage pump, among which the submerged sewage pump is generally used in important places; Seismic foundation, self-irrigating water absorption, and occupying a certain site, so it is less used in construction.

The flow rate of the drainage pump should be selected according to the second flow rate of domestic drainage design; when there is a displacement adjustment, it can be selected according to the maximum hourly flow rate of domestic drainage. The flow rate of the drainage pump in the fire-fighting elevator sump shall not be less than 10L/s.
The head of the drainage pump is determined according to the lifting height and pipeline loss, and then a certain free head is added. The free water 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 spare pump should be set up in each living drainage sump as a unit, and it should be operated interactively at ordinary times. For the drainage of the basement, equipment room, and garage flushing the ground, if there are two or more drainage pumps, the pump may not be used. When the sump cannot be provided with an accident drainage pipe, the pump should have an uninterrupted power supply; when the drainage inlet pipe can be closed, the uninterrupted power supply may not be provided, but an alarm device should be provided.
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 waste water, the outlet pipes of submersible sewage pumps in different sumps can be considered according to the actual situation. .
When two or more pumps share one outlet pipe, a valve and a check valve should be installed on the outlet pipe of each pump. When the drainage of a single pump may cause backflow, a check valve should be installed. It is not allowed to combine the pressure drainage switch with the gravity drainage pipe in the building.
When the submersible sewage pump lifts contains large debris, the submersible sewage pump should be equipped with a crushing device; when the sewage containing more fibers is lifted, a large-channel submersible sewage pump should be used.
When the motor power of the submersible sewage pump is greater than or equal to 7.5kW or the diameter of the water outlet is greater than or equal to DN100, the pump fixed auto-coupling device can be used; when the motor power of the submersible sewage pump is less than 7.5kW or the diameter of the water outlet is less than DN100, the soft Tube mobile installation. When the sewage collection tank is drained by a submersible sewage pump, a fixed self-coupling device for the water pump shall be provided to facilitate the maintenance of the water pump.
The drainage pump should be able to automatically start and stop and manually start and stop on site. Multiple pumps can be operated alternately in parallel, and can also be put into operation in sections.