(1) The horizontal section of the water inlet pipe in contact with the pump applies a descending slope of 0.5% or more to the direction of the water flow, and the end connected to the pump inlet should be at the 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. (2) The pump is not filled with enough water prior to start-up, and sometimes the seeded water overflows from the vent, but the air is not completely discharged by the pump shaft, causing a small amount of air to remain in the intake or pump body. (3) Inlet pipe Due to long-term potential underwater, pipe wall corrosion holes, water pump work continues to decline, when these holes exposed water, the air from the hole into the civilian into the water pipe. (4) The packing of the pump has been worn or the packing pressure is too loose due to the long-term use, resulting in a large amount of water being ejected from the gap between the packing and the shaft sleeve of the pump. As a result, external air enters the pump from these gaps, Affected the mention of water. (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. Pump speed is too low (1) the 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. (2) human factors. Some users due to the original motor damage, it is coupled with another motor-driven, resulting in the flow of filial piety or even the consequences of low water. (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. Suction too much Some of the water is deep and some of the water's outer surface is flat, ignoring the allowable suction of the pump, resulting in little or no water absorption. 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 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. Water flow in the water pipe resistance loss is too large Some users through the measurement, although the vertical distance from the reservoir or water tower to the water surface is slightly less than the head of the pump, but still small amount of water 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 elbow bend than the 120-degree bend resistance, each 90-degree elbow head loss of about 0.5-1 meters, 20 meters of pipe resistance can make head loss of about 1 meter. 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. Other factors (1) The bottom valve can not open. It is usually due to the pump being left on for too long, the bottom valve gasket is stuck, and the bottom valve without gasket may rust out. (2) impeller wear serious. Impeller blades worn by long-term use, affecting the pump performance. (3) the bottom valve filter is clogged; or the bottom valve causes potential clogging of the filter in the sludge layer. (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. Metal Wireworks,Wire Grid,Wire Grill,Wire Stand Huiye Hardware & Electrical Equipment Company Ltd. , https://www.jmhuiyehardware.com