How much is the lift of the fire pump suitable?

The lower the pumping head of the fire pump, the smaller the motor load. Under the misleading of this kind of misunderstanding, when purchasing a water pump, the head of the water pump is often selected to be very high. In fact, for centrifugal water pumps, when the pump model is determined, the power consumption is proportional to the actual flow of the pump. The flow rate of the water pump will decrease with the increase of the head, so the higher the head, the smaller the flow rate and the smaller the power consumption. Conversely, the lower the lift, the greater the flow and the greater the power consumption. Therefore, in order to prevent the motor from overloading, it is generally required that the actual pumping head of the pump should not be lower than 60% of the calibrated head. Therefore, when the high lift is used for pumping water with a low lift, the motor is easily overloaded and heats up, and in serious cases, the motor may be burned. If it is used in an emergency, a gate valve for adjusting the water output must be installed on the outlet pipe (or a small water outlet should be blocked with wood, etc.) to reduce the flow and prevent the motor from overloading. Pay attention to the temperature rise of the motor. If the motor is found to be overheated, the flow of the water outlet should be reduced in time or the machine should be shut down. This is also easy to cause misunderstandings. Some operators think that blocking the water outlet and forcibly reducing the flow will increase the load on the motor. In fact, on the contrary, the outlet pipes of regular high-power centrifugal pump irrigation and drainage units are equipped with gate valves. In order to reduce the motor load when the unit starts, the gate valve should be closed first, and then gradually open the gate valve after the motor starts. This is the reason.