There is air in the inlet pipe of the pump body
(1) Some users are not filled with water before the pump starts; Sometimes it appears that the water has spilled out of the vent, but the pump shaft has not been turned and the air is completely discharged, so that a little air remains in the intake pipe or pump body.
(2) The horizontal section of the water inlet pipe in contact with the water pump should be more than 0.5% of the downward slope in the direction of the reverse water flow. The end of the inlet of the water pump is **, not completely level. If the water pipe is tilted upward, air will be retained in the water inlet pipe, reducing the vacuum degree in the water pipe and pump, and affecting water absorption. The water pump
(3) Because of long-term use of the pump packing has worn or packing pressure too loose, resulting in a large amount of water from the filler and pump shaft sleeve gap ejected, the result is that the external air from these gaps into the interior of the pump, affecting the water.
(4) Due to the long-term potential underwater water intake pipe wall corrosion holes appear, the water surface continues to drop after the pump works, when these holes above the water surface, air will enter the intake pipe from the holes.
(5) There is a crack at the elbow of the water inlet pipe and a small gap at the connection between the water inlet pipe and the water pump, which may make the air enter the water inlet pipe.
Pump speed is too low pipeline pump
(1) Human factors. A considerable number of users due to the damage of the original motor, will be randomly matched with another motor drive, resulting in less flow, low head and even the consequences of not pumping water.
(2) drive belt wear. There are many large water pump from the belt, because of long-term use, drive belt wear and loose, skid phenomenon, thus reducing the speed of the pump.
(3) Improper installation. The two belt wheel core distance is too small or the two shafts are not too parallel, the transmission belt tight edge is installed to the above, resulting in the package Angle is too small, the two belt wheel diameter calculation error and the coupling shaft drive pump two shafts eccentric distance is large, etc., will cause the change of pump speed.
(4) mechanical failure of the centrifugal pump itself. Impeller and pump shaft fastening nut loose or pump shaft deformation bending, resulting in impeller movement, direct friction with the pump body, or bearing damage, it is possible to reduce the speed of the pump.
(5) Power machine maintenance is not recorded. Motor winding burned, and loss of magnetism, maintenance winding turns, wire diameter, wiring method changes, or maintenance fault is not completely eliminated factors will also make the pump speed change.