When choosing a pump, I know the actual flow rate required and the approximate head. So how should the flow rate and head of the pump be determined?
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When choosing a pump, I know the actual flow rate required and the approximate head. So how should the flow rate and head of the pump be determined? Do they all need to be greater than the actual required value? ?
Take 1.1 times the normal operating flow rate as the rated flow rate, and the head under normal operation as the rated head.
First, it is necessary to know the system’s demand, and use this demand as the operating amount. Using this value, hydraulic calculations are performed to determine the pressure loss requirements at the inlet and outlet of the pump, and ultimately the calculated head is obtained. When referring to the data sheet for the pump, safety considerations lead to the operating flow rate and head being multiplied by a safety factor (1.1 or 1.25) to determine the values used for procurement. Once it is in operation, if the pump flow exceeds the system’s requirements, valves are used to adjust it and reduce the flow rate.