Centrifugal pump with its simple structure, easy maintenance, high efficiency and become the most widely used in agriculture, a pump, but also because sometimes mention the water and make you feel annoyed. We will analyze the reasons for not referring to the fault of water. Inlet pipe and pump body air (1) Some users did not fill enough water before the pump started; sometimes it seems that the irrigation water has overflowed from the bleed hole, but did not turn the pump shaft air completely discharged, resulting in a little air still residue In the inlet pipe or pump body. (2) The horizontal section of the inlet pipe in contact with the pump applies a descending gradient of 0.5% or more to the direction of the flow of water, and the one end connected to the inlet of the pump is the highest, not to the full level. If you tilt up, there will be trapped air inlet pipe, reducing the vacuum hose and pump, affecting water absorption. (3) The packing of the pump is 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 flows into the pump from these gaps, Affected the mention of water. (4) 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 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. Pump speed is too low (1) Artificial factors. A considerable part of the user due to the original motor damage, it is coupled with another motor-driven, resulting in less traffic, low lift or even pumping the consequences of the water. (2) belt wear. There are many large pump away from the belt, because of long-term use, the belt wear and loose, there slippage, thereby reducing the pump speed. (3) improper installation. Two pulley center distance is too small or two axes are not parallel, tight belt mounted to the top, resulting in the wrapping angle is too small, the two pulley diameter calculation error and coupling shaft pump two eccentric eccentricity will result in Pump speed changes. (4) 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, directly friction with the pump body, or bearing damage, which may reduce the speed of the pump. (5) Power engine maintenance does not record. Motor due to the winding burned, and loss of magnetism, the maintenance of the winding turns, diameter, connection method changes, or maintenance failure is not completely ruled out factors also make the pump speed change. Suction too much Some deep water, some water outside the flat terrain, while ignoring the pump allowable suction, resulting in little or no water absorption of the results. To know that there is a limit to the degree of vacuum that can be established at the suction port of a pump, the suction at absolute vacuum is about 10 meters high 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 to 8.5 meters, not only when installing the pump is simple and convenient. Water flow into and out of the pipe resistance loss is too large Some users after 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 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 than the 120-degree elbow resistance, each 90-degree elbow head loss of about 0.5 to 1 meter, every 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) at the end of the valve can not be opened. 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) 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 or check valve failure or blockage will result in reduced flow or even pumping on the water. (5) The leakage of pipe leakage will also affect the amount of water.