Centrifugal pump does not start after the start of water, why the centrifugal pump does not start after the start of water pump does not start after the water is what is the reason 1. The inlet pipe and the pump body air (1) before the start of centrifugal pump is not filled with enough water, and sometimes it seems Irrigation water has overflowed from the vent, but did not turn the pump shaft to air 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 centrifugal pump applies a descending gradient of 0.5% or more to the direction of the water flow, and the end connected to the pump inlet should be at its highest level, not the full level. If you tilt up, there will be trapped air inlet pipe, reducing the vacuum hose and pump, affecting water absorption.
(3) Centrifugal pump packing has worn or the packing pressure is too loose due to long-term use, resulting in a large amount of water ejected from the gap between the packing and the pump shaft sleeve. As a result, external air enters the interior of the pump through these gaps , Affecting the water.
(4) Inlet pipe Due to long-term potential underwater, pipe wall corrosion holes, centrifugal pump work continues to decline after the surface water, when these holes exposed water, the air from the hole into the civilian into the water pipe.
(5) cracks in the inlet pipe cracks, inlet pipe and pump connections appear tiny gaps, are likely to make the air into the inlet pipe.
Centrifugal pump speed is too low (1) human factors. Some users due to the original motor damage, it is coupled with another motor driven, the result of a small flow, low lift or even the consequences of the water.
(2) centrifugal pump itself mechanical failure. Loosening of the impeller and the shaft of the pump shaft or the deformation and bending of the shaft of the pump cause the impeller to move more, friction directly with the pump body or damage to the bearing, all of which may reduce the speed of the pump.
(3) power machine repair is not working. Motor due to the winding burned, and lost magnetism, the maintenance of the winding turns, diameter, wiring changes, or maintenance failure is not completely ruled out the factors that will change the pump speed.
Third, multistage centrifugal pump suction too deep Some of the water is deep, some water outside the flat topography, while ignoring the centrifugal pump allowed suction, resulting in little or no water absorption of the results. To know the pump suction port can establish a degree of vacuum is limited, the absolute vacuum suction is about 10 meters high water column, and the centrifugal pump can not establish an absolute vacuum. And the vacuum is too large, easy to pump the water gasification, the work of the pump negative. Therefore, the centrifugal pump has its maximum allowable suction, usually between 3-8.5 meters. Do not install the pump only easy and simple.
Centrifugal pump water flow into and out of the resistance loss is too large Some users after the measurement, although the reservoir or water tower to the water surface of the vertical distance slightly less than the centrifugal pump head, but still mention the amount of water is small or mention the water. The reason is often too long pipes, pipe corners, water flow resistance in the pipeline is too large loss. The reason is often too long pipes, pipe corners, water flow resistance in the pipeline is too large loss. Under normal circumstances, 90-degree bend pipe bending resistance than 120 degrees, each 90-degree elbow head loss of about 0.5-1 meters, 20 meters of pipe resistance can make head loss of about 11 meters. In addition, some users are also free to pump into and out of the pipe diameter, which also has a certain impact on the lift.
Five other factors (1) at the end of the valve can not be opened. Usually because the centrifugal pump is left on hold for too long, the bottom valve gasket is stuck, and the bottom valve without gasket may rust.
(2) The bottom valve filter screen is clogged; or the bottom valve causes potential clogging of the filter screen in the sludge layer.
(3) impeller wear serious. Impeller blades worn by long-term use, affecting the pump performance.
(4) Gate valve can check valve failure or blockage will result in reduced flow or even pumping on the water.
(5) Leakage of the outlet pipe will also affect the amount of water lift.