Analysis of the reasons why the pump does not deliver water

The water pump sometimes cannot pump out water during use. So, what are the reasons that affect the pump not to pump out water? The following is an analysis of the reason why the pump does not deliver water: there is air in the water inlet pipe and the pump body

1) The pump is not filled with enough water before starting. Sometimes it seems that the filled water has overflowed from the vent hole, but the pump shaft is not rotated and the air is completely discharged, resulting in a little air remaining in the inlet pipe or pump body.

2) The horizontal section of the water inlet pipe in contact with the water pump should have a downward gradient of 0.5% or more against the flow direction. The end connected to the inlet of the water pump is the highest, not completely horizontal. If it is tilted upwards, air will remain in the water inlet pipe, which reduces the vacuum in the water pipe and the water pump and affects water absorption.

3) The packing of the water pump has worn out due to long-term use or the packing is too loose, causing a large amount of water to be ejected from the gap between the packing and the pump shaft sleeve. As a result, external air enters the inside of the pump from these gaps, affecting To lift water.

4) Due to long-term potential underwater, the pipe wall has corroded holes and the water surface drops continuously after the pump works. When these holes are exposed to the water surface, air enters the civil water inlet pipe from the holes.

5) There are cracks in the elbow of the inlet pipe, and there is a tiny gap between the inlet pipe and the water pump, which may cause air to enter the inlet pipe.

/