How to choose drainage pump

Drainage pump used in buildings are submersible sewage pump, liquid discharge pump, vertical sewage pump and horizontal sewage pump. Due to small venues and displacement in buildings, submersible sewage pump and liquid discharge pump can be firstly chose to drain the water. Liquid discharge pump is generally used at important places; vibration-isolated foundation, self irrigation and a certain place are required by vertical sewage pump and horizontal sewage pump. Thus, they are rarely used in buildings. Choice and requirements of drainage pump:

The flow of drainage pump should be determined according to the design flow of domestic sewage; when there is displacement adjustment, it can be determined according to the maximum hourly flow of domestic sewage. The flow of drainage pump in fire lift is no less than 10L/s.

After the head of drainage pump is determined according to lifting height and pipe loss, a certain free head should be added. The free head should be 0.02～0.03MPa. The flow of suction and discharge pipe of drainage pump should be no less than 0.7m/s and no more than 2.0m/s.

A stand-by pump should be set for each unit with each living drainage sump as a unit in public buildings and they are should be interactive operation at ordinary times. If there are two or more drainage pumps, the stand-by pump is not necessary for the drainage of basement, machine room and water for rinsing garage ground. If the sump cannot be set accident drain pipe, the power supply should be continued for the pump; if the drain inlet pipe can be closed, the continued power supply is not necessary, while warning device should be set.

When lift sewage and waste water with large impurities, outlet pipes of submersible sewage pumps of different sumps should not be combined to discharge; when lift the normal sewage, it can be determined according to the actual situation if outlet pipes of submersible sewage pumps of different sumps are combined to discharge or not.

When two or more pumps share a outlet pipe, the valve and check valve should be installed on the outlet pipe of each pump. Drainage by a single pump may occur flow backward, so check valve should be installed at this time. Pressure drainage pipe and gravity drainage pipe in buildings are prohibited to be combined to discharge.

When submersible sewage pump lifts sewage containing large debris, submersible sewage pump should be equipped with a crushing device; when it lifts sewage containing many fibrous materials, large channel submersible sewage pump is properly adopted.

When motor power of submersible sewage pump is large than or equal to 7.5kW or diameter of outlet pipe is larger than or equal to DN100, the pump can be used to fix the coupling device; when motor power of submersible sewage pump is less than 7.5kW or diameter of outlet pipe is less than DN100, the hose can be set by mobile installation. When sewage sump discharges water by submersible sewage pump, the pump should be set to fix coupling device, which is convenient for maintenance of pump.

Drainage pump should be started and stopped automatically and manually. Several pumps can be operated in parallel and segmentally.