Hello, welcome to the official website of Dongguan Chunnan Pump Co., Ltd!



The pump can't pump water

Date: November 8, 2015 popularity: 122
Fault condition:
The pump operates normally, but it can not reach the standard flow and head of the pump;
Cause of failure:
There is air in the inlet pipe and pump body
(1) Some users did not fill up enough water before the pump was started;
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 water 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 more than 0.5% against the water flow direction. The end connecting the water pump inlet is the highest and should not be completely horizontal. If it is tilted upward, air will be left in the water inlet pipe, which will reduce the vacuum degree in the water pipe and water pump and affect the water absorption.
(3) The packing of the pump has been worn or the packing is too loose due to long-term use, resulting in a large amount of water ejected from the gap between the packing and the shaft sleeve of the pump. As a result, the external air enters the interior of the pump from these gaps, affecting the water lifting.
(4) Because of the long-term potential underwater, there are holes in the pipe wall corrosion of the inlet pipe. After the pump works, the water surface continues to drop. When these holes come out of the water surface, air enters the inlet pipe through the holes.
(5) Cracks at the elbow of the water inlet pipe and a small gap between the water inlet pipe and the water pump may cause air to enter the water inlet pipe.
Pump speed too low
(1) Human factors. Due to the damage of the original motor, quite a number of users randomly equipped with another motor to drive. As a result, the flow rate is low, the head is low and even the water can not be pumped.
(2) The drive belt is worn. Because of the long-term use of large-scale water pump, the transmission belt has been reduced due to sliding.
(3) Improper installation. If the center distance between the two pulleys is too small or the two shafts are not parallel, the tight edge of the drive belt is installed on it, the wrap angle is too small, the calculation error of the diameter of the two pulleys and the large eccentricity of the two shafts of the coupling drive water pump will cause the change of the pump speed.
(4) Mechanical failure of water pump itself. Loose fastening nut of impeller and pump shaft or deformation and bending of pump shaft cause impeller to move more, directly rub with pump body, or bearing damage, which may reduce the speed of water pump.
(5) Power machine maintenance is not recorded. The motor loses its excitation due to the burning of its winding. The change of winding turns, wire diameter and wiring method in the maintenance, or the failure is not completely eliminated in the maintenance, will also change the speed of the water pump.

Product catalog