When we select the type of water pump, the head of the water pump is first determined by theoretical calculation, and there are often some errors, which cause the head of the selected water pump to be higher (in most cases) or lower (rarely) than the head required by the actual device, resulting in the pump running under partial conditions. Due to the partial operating conditions, it will cause some operating failures as follows:
(1) Motor overpower (current), often appearing on centrifugal pumps.
(2) Cavitation occurs in the water pump, accompanied by vibration and noise, and the pointer of the outlet pressure gauge swings frequently. Due to the occurrence of cavitation, impeller cavitation damage is also caused, and the operating flow is reduced.
Treatment measures: analyze the pump operation data, re-determine the actual lift required by the device, and adjust (reduce) the pump lift. The easiest way is to cut the outer diameter of the impeller; if the cutting impeller is not enough to meet the requirements of the head reduction value, the newly designed impeller can be replaced; the motor can also be modified to reduce the speed to reduce the pump head.
