What is the reason for the low speed of the multi stage centrifugal pump after startup?

(1) human factors. Some users because of original motor damage, may be accompanied by another motor, resulting in a flow of small, low head or even the consequences of Sheung shui.

(2) the mechanical failure of the centrifugal pump. Impeller and pump shaft fastening nut loose or pump shaft deformation and bending, resulting in multi impeller, direct friction with the pump body, or bearing damage, it is possible to reduce the pump speed.

(3) power machine maintenance. Motor due to the winding burn, and loss of magnetism, maintenance of the winding turns, wire diameter, wiring method changes, or the failure of the maintenance of the fault is not completely eliminated factors will make the pump speed change.

(4) before starting the multi-stage centrifugal pump is not filled with enough water, sometimes it looks like the water from the vent overflow, but did not turn the pump shaft to the air completely discharged, resulting in a little air left in the water pipe or pump body.

(5) in contact with the multistage centrifugal pump inlet of the horizontal application of reverse flow direction, fell more than 0.5 slope, connect one end of the highest import pumps, do not completely level. If the upward tilt, will be retained within the inlet air, reduce water pipes and pumps in the vacuum, the impact of water.

(6) a multistage centrifugal pump packing has been used for long-term wear or packing pressed too loose, discharge gap caused by the large amounts of water from filling with the shaft sleeve, the external air gap into the pump from the inside, affected the water.

(7) because of the long-term potential of the water pipe, the pipe wall corrosion appeared holes, the water level of the multi-stage centrifugal pump was decreased. When these holes are exposed, the air enters the water inlet pipe from the hole.

(8) there is a crack in the water inlet pipe bend pipe, the water inlet pipe and the water pump connection in the small gap, it is possible to make the air into the water inlet pipe.