How To Choose A Deep Well Pump

Aug 27, 2025

It is difficult to distinguish between various types of deep well pumps on the market based solely on their specifications. So how to choose a deep well pump? Here are some insights on deep well pump selection summarized by industry insiders.

1, Determine the pump type based on the wellbore diameter and water quality. Different types of pumps have certain requirements for the diameter of the wellbore, and the maximum external size of the pump should be 25-50mm smaller than the wellbore diameter. If the wellbore is skewed, the maximum external size of the pump should be smaller. In short, the pump body should not be tightly attached to the inner wall of the well to prevent pump vibration from damaging the well.

2, Select the flow rate of the well pump based on the water output of the well. Each well has an economically optimal water output, and the flow rate of the pump should be equal to or less than the water output when the well water level drops to half the depth of the well water. When the pumping volume exceeds the water output of the well, it will cause the collapse and sedimentation of the well wall, affecting the service life of the well; If the pumping volume is too small, the benefits of the well cannot be fully utilized. So, the best approach is to conduct a pumping test on the well, using the maximum water output that the well may provide as the basis for selecting the pump flow rate. The flow rate of the water pump shall be based on the brand model or the number indicated in the manual.

3, Based on the depth of water level drop in the well and the head loss of the water supply pipeline, determine the actual required head of the well pump, that is, the head of the well pump, which is equal to the vertical distance from the water level to the water surface of the outlet pool (net head) plus the loss head. The loss head is usually 6-9% of the net head, usually 1-2m. The inlet depth of the lowest stage impeller of the water pump should be 1-1.5m. The total length of the underground part of the water pump pipe should not exceed the maximum length specified in the water pump manual for entering the well.

4, It is not advisable to install and use deep well pumps in wells with a sand content exceeding one ten thousandth. Because the sediment content in well water is too high, if it exceeds 0.1%, it will accelerate the wear of rubber bearings, cause water pump vibration, and shorten the service life of the water pump.