Drainage pumps used in buildings include submersible sewage pumps, submersible drainage pumps, vertical sewage pumps and horizontal sewage pumps. As the general site of the building is smaller, the displacement is not large, the drainage pump can give priority to the submersible sewage pump and submerged drainage pump, which submerged sewage pump is generally used in important places; vertical sewage pump and horizontal sewage pump required to set the interval The basis of the earthquake, self-filling suction, and occupy a certain site, it is less used in the building. Drainage pump flow rate should be selected according to life drainage design second flow; when the displacement adjustment, according to the life drainage maximum hour flow selected. Fire elevator pool drain pump flow rate of not less than 10L / s. Drainage pump lift by lifting height, pipe loss calculation is determined, then add a certain free head. Free head should adopt 0.02 ~ 0.03MPa. Drainage pump suction pipe and outlet pipe flow rate should not be less than 0.7m / s, and should not be greater than 2.0m / s. Public buildings should be used for each living drainage cistern as a unit to set up a spare pump, usually should be run interactively. Basement, equipment room, garage flushing the ground drainage, if there are two or more than two drainage pump equipment pump. When the catchment can not set the accident drain, the pump should have uninterrupted power supply; when you can close the drainage pipe, it may not provide uninterrupted power supply, but should set the alarm device. When upgrading sewage and wastewater with larger impurities, the outlet pipes of the submersible sewage pump in different sumps should not be merged and discharged. When upgrading the general wastewater, the discharge pipes of submersible sewage pumps of different sumps may be merged and discharged according to the actual situation . When two or more pumps share one outlet pipe, a valve and a check valve shall be installed on each outlet pipe of the pump. A single pump drainage may occur when the backflow should be set check valve. Do not allow the pressure drain and the building gravity drainage pipe merged discharge. When the submersible sewage pump to enhance large debris, the submersible sewage pump should be equipped with a comminution device; when upgrading with more fibrous waste water, should adopt a large submersible sewage pump. When the submersible sewage pump motor power is greater than or equal to 7.5kW or outlet diameter greater than or equal to DN100, the pump can be used to fix the auto-coupling device; when the submersible sewage pump motor power is less than 7.5kW or the outlet diameter is less than DN100, Tube mobile installation. Sewage collection pond submersible sewage pump drainage, water pumps should be set fixed auto-coupling device to facilitate pump maintenance. Drainage pump should be able to automatically start and stop and on-site manual start and stop. Multiple pumps can be alternately operated in parallel, but also can be put into operation in stages.