Do You Know That High-head Pumps Cannot Be Used As Low-head Pumps?

High-head submersible pumps are widely used, mainly for irrigation in farmlands, water supply in urban and rural areas, industrial enterprises, and domestic water extraction. Choosing the right pump is also of great significance for energy conservation.
When selecting a pump, we usually ask the user about the required flow rate and head. If the flow rate and head cannot be specified precisely, then it is impossible to accurately select the equipment.
Many users believe that choosing a pump with a higher lift range will enable it to be used in a wider range of applications. Due to this misconception, when purchasing a pump, they tend to choose one with a higher lift range.
In fact, for centrifugal pumps, their power consumption is directly proportional to the actual flow rate. Once the pump model is determined, for this pump, when the application head is lower, the flow rate will increase, and a larger flow rate means greater power consumption, resulting in a higher current. And a smaller flow rate means lower power consumption. Therefore, to avoid motor overload, it is generally required that the actual head of the pump should not be lower than 60% of the rated head.
Therefore, when a high-head pump is used for a low-head application, it is prone to cause the motor to overheat. In severe cases, it may even result in the motor being burned out. Even if it is only for emergency use, it must also be regulated by a water outlet valve installed on the outlet pipe to control the flow rate. Generally, a self-operated regulating valve (or a wooden block, or other methods) can be used to reduce the water flow and prevent the motor from overloading. If the motor overheats, reducing the water outlet flow or shutting down the machine in time can prevent the motor from being burned out.
Some users try to reduce the flow rate by lowering the power supply voltage. This approach is incorrect because the opposite is true - reducing the power supply voltage will increase the motor load. Centrifugal pump irrigation stations all have valves at the outlet pipe to achieve the purpose of reducing the motor load. During normal operation, it is best to close the valve before the pump stops, and slowly open the valve after the pump starts to prevent it from operating with excessive current.
Therefore, the selection of the head is of vital importance. When purchasing a water pump, one must first clearly understand the required head or outlet pressure, so as to accurately choose the appropriate pump.