1. Some users are not filled with water before enough water; sometimes as irrigation water from the overflow holes, but did not cross shaft rotation entirely from the air, resulting in a little air still left in the inlet or the pump in.
2. Contact with the water pump water level of the pipe section against the flow direction of the application of more than 0.5% of the decline in the slope, connect one end of the pump inlet of the highest, not to complete the level. If the upward tilt, will be retained within the inlet air, reduce water pipes and pumps in the vacuum, the impact of water.
3. Centrifugal pump packing used for long-term wear and tear or packing has been pressed too loose, causing a lot of water ejected from the shaft sleeve and fill the gap, the result is outside air into the pump from the gap, affecting the water extraction.
4. Because of the long-term potential of the water inlet pipe, the pipe wall corrosion appear holes, water pump works, the water continued to decline, when these holes exposed, the air from the hole into the water inlet pipe.
5. The water inlet pipe bends in the cracks, the water inlet pipe and the water pump connection at the small gap, it is possible to make the air into the water inlet pipe.
