Reasonable selection of water treatment equipment is the knowledge that every designer needs to master. As the core equipment of transportation and lifting, pumps are everywhere in water treatment projects. Therefore, how to select the pump is also very important! Usually, when selecting the type of water pump, we will ask the user how much is the flow head required? If the flow head cannot be determined, it cannot be selected correctly.

Before purchasing the water pump, many users think that under the condition of lower head, they choose a higher head water pump with a wider range of head. In this misleading misconception, when buying a water pump, the selected pump head is very high.

In fact, for centrifugal pumps, when the pump model is determined, its power consumption is directly proportional to the actual pump and flow. When the service head of the pump is low, the flow will increase; Thus, the current is higher, the flow is smaller, and the power consumption is lower. On the contrary, lower head, greater flow and greater power consumption. Therefore, in order to prevent motor overload, it is generally required to use pump pumping head, and the actual calibrated head shall not be less than 60%.  

Therefore, when the high lift pump is used for low lift, it is easy to overload, the motor is easy to heat, and the motor is burned out in serious cases. In case of emergency use, It must be regulated by a water outlet valve installed on the water outlet pipe. Usually, a self operated regulating valve can be used (or wood blocks, and other methods) to reduce the water flow and prevent the motor from overload. Pay attention to the motor temperature. If the motor is overheated, small water outlet flow or shut down in time can avoid burning the motor. Some users forcibly reduce the flow by reducing the power supply voltage, which will increase the motor load. In fact, on the contrary, the unit outlet pipe of centrifugal pump drainage and irrigation station is equipped with To reduce the motor load, the valve shall be closed before the water pump is shut down. After the water pump is started, the valve shall be opened gradually so that there will be no overcurrent during startup.

It should be installed in this way: install the low lift pump in front of the high lift pump, that is, the outlet water of the low lift pump is sent to the inlet of the high lift pump. There is a problem that the outlet pressure of the low lift pump cannot exceed the upper limit of the inlet pressure of the high lift pump, otherwise it is easy to cause overpressure and water leakage.