1. Preliminarily determine the pump type according to the well diameter and water quality.
Different types of pumps have certain requirements on the diameter of the well hole. The maximum external dimension of the pump should be 25-50mm smaller than the well diameter. If the wellbore is skewed, the maximum external dimension of the pump should be smaller. In short, the part of the pump body cannot be close to the inner wall of the well, so as to prevent the vibration of the water pump from damaging the well.
2. Select the flow rate of the deep well vertical turbine pump according to the water output of the well.
Each well has an economically optimal water output, and the flow rate of the water pump should be equal to or less than the water output when the water level of the pumped well drops to half the depth of the well. When the pumped water is greater than the water output of the motor-driven well, it will cause the wall of the motor-driven well to collapse and deposit, which will affect the service life of the well; if the pumped water is too small, the benefits of the well will not be fully utilized. Therefore, the best way is to conduct a pumping test on the motor-driven well, and use the maximum water output that the well may provide as the basis for selecting the pump flow rate of the well.
3. The head of the deep well vertical turbine pump.
According to the drop depth of the well water level and the head loss of the water delivery pipeline , determine the actual lift required by the well pump, which is equal to the vertical distance from the water level to the water surface of the effluent pool (net head) plus the lost head. The loss head is usually 6-9% of the net head, generally 1-2m. The water entry depth of the bottom stage impeller of the pump is preferably 1-1.5m. The total length of the downhole part of the pump tube should not exceed the maximum length specified in the pump manual.
It should be noted that deep well pumps should not be installed in motor-driven wells where the sand content in the well water exceeds 1/10,000. Because the sand content in the well water is too large, if it exceeds 0.1%, it will accelerate the wear of the rubber bearing, cause the pump to vibrate, and shorten the life of the pump.