If you find that the high-pressure pump does not produce water, it means that there is air in its water inlet pipe and pump body. It is usually because the high-pressure pump has not been filled with enough water before starting. Sometimes it seems that the filled water has overflowed from the vent hole, but the pump shaft has not been rotated. Exhaust air is completely discharged, causing a little air to remain in the inlet pipe or pump body.

Therefore, it is required that the horizontal section of the water inlet pipe that is in contact with the high-pressure pump should have a downward slope of more than 0.5% against the flow direction, and the end connected to the inlet of the high-pressure pump should be high, 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 high-pressure pump, and affects water absorption.

Of course, if the high-pressure pump does not discharge water, it is also possible that the packing 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 high pressure from these gaps. The inside of the pump affects the lifting of water.