Traditional method for selecting soft shaft centrifugal pumps: First, determine the required head curve based on the net lift height and installation form of the pump station. Then, according to the design flow rate, determine the loss head of the selected pump. Subsequently, determine the total head to ensure the selected pump operates efficiently at the design head..It can be observed that traditional pump selection methods are based on the combination of constant flow rate and increasing head, without considering the efficiency of the pump unit at the designed head..Assuming the design point for the hypothetical device isA(QZ，HZ).When selecting pumps using traditional methods, the pump head is calculated according to the following formula:HP=HZ+SQ2
    Reasons for Low Speed of Agricultural Flexible Shaft Pumps
    (1)Human factors. Some users, upon the failure of the original motor, arbitrarily paired another motor to drive it, resulting in low flow, low head, and even failure to pump water.
    (2)Mechanical failure within the pump itself. Loosening of the fastening nuts between the impeller and the pump shaft, or deformation and bending of the pump shaft, can cause excessive movement of the impeller, leading to direct friction with the pump body or bearing damage, all of which may reduce the pump's rotational speed.
    (3)Engine repair is not functioning properly. The motor has lost its magnetism due to the burnout of the winding, and changes in the number of turns, wire diameter, or wiring method during maintenance, or failure to completely eliminate the fault during repair, can also alter the pump's speed. The suction head is too great; some water sources are deep, and some are surrounded by flat terrain, which ignores the pump's allowable suction head, resulting in insufficient water intake or inability to draw water at all. It is important to know that the vacuum level that can be established at the pump's suction port is limited, with the vacuum suction head approximately...10The water column height is substantial, and it is impossible for a pump to establish a vacuum. Moreover, an excessive vacuum can cause the water inside the pump to vaporize, which is detrimental to the pump's operation. Therefore, each centrifugal pump has its maximum allowable suction head, usually...3-8.5During the installation of water pumps, it is crucial not to prioritize convenience and simplicity. Excessive resistance loss in the inlets and outlets of the water pipes can be a problem. Some users have measured that even though the vertical distance from the storage tank or water tower to the water surface of the water source is slightly less than the pump's head, the water flow is still insufficient or the pump cannot lift water. The common cause is often excessively long pipelines and numerous bends in the water pipes, resulting in significant resistance loss within the pipes. Generally speaking,90Degree bend pipe120Please provide the Chinese content you would like translated into American English.90Please provide the Chinese content to be translated.0.5-1Sorry, there is no Chinese content provided to translate. Please provide the text you would like to be translated.20The resistance of the mill pipe can cause approximately1In addition, some users arbitrarily adjust the pipe diameters of the pump's inlet and outlet, which also have an impact on the head.
    Why Are Agricultural Flexible Shaft Pumps Not Pumping Water?
    (1)The bottom valve is stuck open. Small bore flexible shaft deep well pumps often suffer from this issue due to prolonged storage, where the bottom valve gasket becomes stuck, or the valve without a gasket may rust shut.
    (2)The bottom valve filter screen is clogged.;The orifice valve may cause filter screen blockage by being submerged in the sludge layer in the potential water.
    (3)The impeller has experienced severe wear. The blades of the impeller have worn down over prolonged use, affecting the pump's performance.
    (4)Valves with non-return function can experience malfunctions or blockages, leading to reduced flow or even the inability to pump water.
    (5)Leakages in export pipelines can also affect water extraction capacity.
    Reason1.The water level has dropped to the level of the filter mesh.
    2.Propeller shaft breaks
    3.Water pipe bursts
    Elimination Method:
    1.Appropriately increase1-2Genyang Water Piping and Propeller Shafts
    2.Disassemble the pump and identify the cause of the damage.
    3.Replace damaged parts