The minimum submerged depth of pump is to ensure the normal operation of the pump necessary conditions, the manufacturer’s samples are marked with clear data, forever pump pointed out that the data is calculated based on:
1. According to the calculation of the pump NPSH to ensure that the pump does not cavitation.
2. For the submersible pump in the upper part of the motor, if the motor cooling circulation system is not installed, the whole motor is immersed in the water to cool the motor stator.
3. The minimum submergence depth is to ensure that the pump is running, the suction pool water does not occur whirlpool, the air is not involved in the pump inlet, and to ensure uniform distribution of the liquid into the pump speed.
Moreover, the permanent pump plant found that some pumping stations due to flow and suction pool conditions, the pump running after the water level changes greatly, the suction pool water level drops, resulting in the actual submerged depth below the minimum submergence depth, resulting in the pump can not run properly, Cavitation occurred. Such as a pump station, suction pool minimum water level elevation of 1m, up to 4.5m, water depth difference of 3.5m. If the pumping station is designed according to 1m elevation, the whole pumping station will be dug deeply. Raising the elevation design will cause the submerged depth to be less than the minimum submerged depth.
