How to select submersible pumps

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The drainage pumps used in buildings include submersible sewage pumps, submerged drainage pumps, vertical sewage pumps, and horizontal sewage pumps. Since the space inside buildings is usually limited and the volume of wastewater to be drained is not large, submersible sewage pumps and submerged drainage pumps can be preferred as drainage pumps; among these, submerged sewage pumps are generally used in important locations ； Vertical sewage pumps and horizontal sewage pumps require isolation foundations, self-priming suction, and occupy a certain amount of space, which is why they are less commonly used in buildings. 　　The flow rate of the drainage pump should be determined based on the designed second-flow rate for domestic wastewater ； When there is a capacity adjustment, it can be determined based on the maximum hourly flow rate of domestic wastewater. The flow rate of the drainage pump in the fire elevator sump must be no less than 10 L/s. After the head of the drainage pump is determined based on the lift height and pipeline losses, a certain amount of free head is added. The free head should be set at 0.02–0.03 MPa. The flow velocity in the suction and discharge pipes of the drainage pump should not be less than 0.7 m/s, nor should it exceed 2.0 m/s. In public buildings, a standby pump should be installed for each domestic wastewater collection tank, and these pumps should operate in alternation under normal conditions. For the drainage of floors in basements, equipment rooms, and garages, an alternate pump is not required if there are two or more drainage pumps. When it is not possible to install an emergency drainage pipe in the collection tank, the pump must have an uninterrupted power supply ； When it is possible to shut off the drainage inlet pipe, a continuous power supply is not required, but an alarm device should be installed. When lifting dirty or wastewater containing high levels of impurities, the outlet pipes of the submersible sewage pumps in different collection tanks should not be combined for discharge 　　 ； When lifting general wastewater, the outlet pipes of the submersible sewage pumps from different collection tanks can be combined for discharge, depending on the actual circumstances. When two or more pumps share a single outlet pipe, valves and check valves should be installed on the outlet pipe of each pump. When backflow may occur during drainage by a single water pump, a check valve should be installed. It is not allowed to combine the pressure drainage outlet with the gravity drainage pipes inside the building for discharge. When a submersible sewage pump is used to lift liquids containing large debris, it should be equipped with a crushing mechanism ； When lifting sewage containing a high amount of fibers, it is advisable to use submersible sewage pumps with large channels. When the motor power of the submersible sewage pump is 7.5 kW or more, or the diameter of the outlet pipe is DN100 or more, a fixed autotransformer device for the pump can be used ； When the motor power of the submersible sewage pump is less than 7.5 kW or the diameter of the outlet pipe is less than DN100, it can be installed in a portable hose-mounted configuration. When a submersible sewage pump is used for draining wastewater from collection tanks, a fixed autotransformer device for the pump should be installed to facilitate its maintenance. The drainage pump should be able to start and stop automatically as well as manually on-site. Multiple water pumps can be connected in parallel and operated alternately, or they can be brought online in stages.

Head/flow rate/medium – it is necessary to know these three basic parameters in order to select the appropriate model!!!!

The simplest way is to find a distributor, tell them your requirements, and let them help you choose the right model.