The deep well pump is a vertical multistage centrifugal pump that can lift water from the deep well. As the groundwater level drops, deep well pumps are more widely used than ordinary centrifugal pumps. However, due to improper choices, some users have problems such as not being able to fit in, insufficient water, unable to pump water, or even damaging the well. So, how do users choose deep well pumps?
1. According to the water output of the well, select the flow rate of the well pump. Each well has an economically optimal water output. The flow rate of the pump should be equal to or less than the water output when the water level of the machine well drops to half of the well water depth. When the pumping volume is greater than the water output of the machine well, it will cause the wall of the machine well to collapse and silt, affecting the service life of the well; if the pumping amount 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 machine well, and use the maximum water output of the well as the basis for the pump flow of the selected well. The flow rate of the pump is subject to the model number or the number marked on the instruction manual.
2. Machine wells with a sediment content of well water exceeding 1 in 10,000 should not be installed with deep well pumps. Because the sand content of the well water is too large, if it exceeds 0.1%, it will accelerate the wear of the rubber bearing, cause the vibration of the pump, and shorten the life of the pump.
3. Initially determine the pump type according to the well diameter and water quality. Different types of pumps have certain requirements for the diameter of the wellbore. The maximum external size of the water pump should be less than the diameter of 25-50mm. If the borehole is skewed, the maximum external dimensions of the pump should be smaller. In short, the part of the pump body should not be close to the inner wall of the well to prevent damage to the well due to the vibration of the waterproof pump.
Fourth, according to the depth of the well water level and the loss of the water head of the pipeline, determine the actual head required by the well pump, that is, the head of the well pump, which is equal to the vertical distance (net head) from the water level to the water surface of the outlet pool plus the lost head. The loss head is usually 6 to 9% of the net head, usually 1 to 2m. The water depth of the first-stage impeller at the bottom of the pump should be 1～1.5m. The total length of the underground part of the pump pipe should not exceed the maximum length of the well into the well as specified in the pump manual.