High head pumps cannot be used at low head

High head pumps cannot be used at low head

Before buying a pump, many users think that a pump with a higher head will be used for a wider range of heads for lower head conditions. In this misleading misunderstanding, when buying a water pump, the pump head selected is very high. In fact, for centrifugal pumps, when the pump model is determined, its power consumption is proportional to the actual pump and flow size. The flow will increase when the pump is used with a lower head; thus higher current, smaller flow, and lower power consumption. Conversely, lower head, greater flow, greater power consumption. Therefore, in order to prevent the motor from overloading, it is generally required that the actual calibration head of the pump should not be lower than 60%. Therefore, when a high-head pump is used for a low-head, the motor is easily overloaded, and the motor is easily burned out in severe cases. If it is used in an emergency, it must be adjusted with a water outlet valve installed in the outlet pipe. Usually, a self-operated regulating valve (or wood block, and other methods) can be used to reduce the water outlet flow and prevent the motor from being overloaded. Pay attention to the temperature of the motor. If the motor is overheated, the small outlet flow or shut down in time can avoid burning the motor. Some users force a reduction in flow by reducing the power supply voltage, which will increase the motor load. In fact, on the contrary, the unit outlet pipe of the centrifugal pump irrigation and drainage station is equipped with a valve to reduce the motor load.

The pressures of the pumps in series are cumulative.

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