Troubleshooting measures for water pump discharge without water flow
Before starting the pump unit of the pump station, whether operated locally or remotely, the inlet valve and maintenance valve must be opened to fill the pump body with water, discharge the pipeline and accumulated gas in the pump body, close the outlet valve to start (reduce the starting power), and wait for the pressure gauge or pressure sensor on the outlet pipeline to display the rated pressure before opening the outlet valve. Before starting the water pump unit, during the exhaust or vacuum pumping process, pay close attention to the pressure gauge indication of the pipeline, check that the inlet pipeline or the connected vacuum pump pipeline is well sealed and there is no air entering. If there are no problems with the above equipment and links, and the pressure gauge or pressure sensor of the outlet pipeline still shows that the pressure does not reach the rated value, it is necessary to check whether the phase sequence of the motor is correct, turn on the water pump to check whether the impeller is installed in reverse, and whether the inlet or blades are blocked by foreign objects.
Troubleshooting measures for insufficient water pump flow
Keep the water level of the pump station's intake channel or water tank not lower than the design elevation. The inlet or impeller inlet channel of the pump should be cleaned and kept unobstructed. If the pump body or suction pipeline is not tightly sealed or has aged and perforated, repair the leaking part. Repair or replace severely worn impellers or sealing rings. Verify the outer diameter of the impeller, outlet blade width, and other data against the drawings.
Troubleshooting measures for abnormal operation sound
It is necessary to carefully distinguish the type of abnormal sound. If you hear a crackling sound like a popping bean, it is a cavitation phenomenon inside the water pump. It is necessary to check whether the water level in the inlet pool has reached the design elevation, and whether there are any leakage parts in the pipeline and pump body. If there is a periodic collision sound, it may be due to friction between the impeller and the pump body, friction between the impeller mouth edge and the sealing ring, or loose rotor components. It is necessary to shut down the pump and open the pump cover to inspect the various assembly parts of the pump body and rotor, and repair or replace them according to the situation. If there is occasional dull abnormal sound, it is usually caused by foreign objects such as stones being sucked into the pump body and colliding, and can continue to operate and observe.
Troubleshooting measures for pump body vibration
The water level of the pump station's intake channel or water tank meets the operating regulations. If the vibration of the pump body exceeds the standard during operation, first carefully check whether the sealing water is unobstructed, whether there is air leakage in other parts of the pump body and pipeline, and whether the packing or mechanical seal is damaged and needs to be replaced. After excluding factors related to air leakage, specialized instruments need to be used for testing. The vibration should be measured at the base of the motor and water pump, the opening of the pump body, and the bearing seat, and compared with normal operation or other units to preliminarily determine whether the vibration exceeding the standard fault is caused by the motor or water pump. At this point, the unit should be shut down. Firstly, the concentricity of the unit should be checked. If the exceedance value is large, concentricity correction should be carried out. If the exceedance value is small, vibration may be caused by other reasons, and further inspection is needed. The pump cover should be opened to check whether the pump body and rotor assembly components are intact, whether there is any rotor center deviation, whether the installation of bearings and bearing bodies complies with the regulations, and whether the pump shaft or rotor balance test is verified on the lathe.
Troubleshooting measures for bearing temperature rise exceeding the standard
The temperature rise of the bearing exceeds the standard, usually manifested as two situations: slow rise and rapid rise. The temperature is slowly rising, which may be caused by a lack of oil in the bearing, excessive oil volume or impurities in the oil, blocked cooling water, offset centerline, etc. The cooling water in the bearing body can be checked and cleared, and the bearing body can be refilled or replaced with oil (the bearing body and bearings should be thoroughly cleaned at the same time when changing the oil), or the concentricity of the unit can be corrected. If the temperature of the bearing rises sharply, it is often due to sudden damage during the operation of the bearing, loosening or detachment of the bearing nut and back cap, friction with the bearing body, pump shaft fracture, and sudden displacement of the unit centerline. During maintenance, the assembly data of the bearings did not comply with the regulations, and the temperature of the bearings rose sharply at the moment of starting the water pump.
Troubleshooting measures for excessive leakage of packing seal
The packing specifications and number of turns for each type of water pump installation are not the same, and should be installed according to the packing specifications, size, type, and number of turns required by the water pump design. The filling method of the packing is crucial, and the length must be cut according to the size of the shaft sleeve (journal) to a sufficient length to form a circle. The cut should be oblique (45 ° angle), and the joints of adjacent packing rings in the packing box should be staggered by 120 °~180 °. The water seal ring should be aligned with the position of the water seal pipe mouth and slightly installed outward. When installing the outer packing, tighten the packing cover and compress the packing. The water seal ring moves inward and precisely aligns with the water seal pipe hole. The packing cover cannot be installed in a skewed manner. The packing materials used in the Yanghuang pump station water pump generally include aramid fiber packing, graphite rubber packing, metal reinforced graphite packing, carbon fiber reinforced graphite packing, tetrafluoroethylene packing, etc. If the packing material is too soft, it is easy to wear, and if it is too hard, it is easy to wear the pump shaft or shaft liner. The appropriate material and hardness of the packing should be selected based on factors such as water pump head, sealing water quality, speed, and maintenance cycle. After general maintenance, the packing gland nut of the water pump should not be tightened too tightly to prevent the packing from losing elasticity. When the water pump starts, excessive resistance may cause power loss, and the packing may overheat and smoke, affecting durability. Therefore, it should be gradually tightened and adjusted according to the leakage situation of the packing box when the water pump starts. The clearance between the various components of the pump body packing box must be strictly controlled during maintenance. The radial clearance between the packing sleeve and the shaft sleeve is 0.3mm~0.5mm, the radial clearance between the outer circle of the seasoning cover and the inner hole of the packing box is 0.1mm~0.2mm, and the radial clearance between the inner hole of the packing cover and the pump shaft sleeve (shaft) is 0.4mm~0.5mm.
Troubleshooting measures for excessive leakage of mechanical seals
Check and clear the cooling water in a timely manner during operation to prevent blockage; The sealing surface material should be selected with high temperature resistance, weak alkali and acid resistance, and excellent wear resistance to prevent water leakage during operation due to poor durability. During maintenance, check the springs and rubber rings, and replace those that have aged and lost their elasticity in a timely manner. Scratches on the friction surface of the dynamic and static rings of the mechanical seal should be repaired before use.
Troubleshooting measures for sealing gasket leakage
During the maintenance of the water pump, the opening surface of the pump body should be carefully inspected, and repair welding, polishing, or coating should be carried out on the parts affected by mechanical collision or scratching to ensure the flatness of the opening surface of the pump body; Most asbestos pads, paper pads, or rubber gaskets are installed by cutting and splicing. Poor splicing can lead to sealing failure. Generally, the splicing parts should be made in a serrated shape, and the staggered splicing parts should be tightly fitted without displacement or gaps. When installing the pump cover, it is necessary to prevent the gasket from shifting. Do not apply oil or stick the fixed sealing gasket extensively on the middle opening surface, as this method may cause the sealing gasket to shrink and deform. The tightening torque of the bolts and nuts connecting the upper and lower parts of the pump body should meet the installation standards to prevent water leakage due to insufficient tightening torque.
Troubleshooting measures for excessive power consumption
The reasons for excessive power on the pump shaft are multifaceted. If the packing gland is pressed too tightly, it will increase the frictional resistance between the packing and the shaft sleeve (shaft neck), as well as the pump packing box. Therefore, the tightness of the packing gland should be adjusted according to the size of the sealing water in the packing box at any time. During the operation of the water pump, it is necessary to maintain the water level in the inlet pool not lower than the design water level to prevent low water level operation from causing air intake into the water pump suction pipe and increasing shaft power. During operation, it is necessary to strengthen monitoring. When abnormal sounds, excessive shaft movement or jumping, or increased power are found inside the water pump, the cause should be analyzed in a timely manner. If necessary, the pump should be shut down for maintenance to check whether any components of the water pump have malfunctioned and whether the dimensions of each component meet the regulations
