Five main faults of hot water centrifugal pumps and how to resolve them

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Hot water centrifugal pumps are widely used in industries such as metallurgy, chemicals, energy, textiles, and papermaking, as well as in hotels and restaurants, for the pressurized circulation of high-temperature hot water in boilers and for use in urban heating systems. The operating temperature limit for IRG (ISWR) pumps is ≤120°C, while that for GRG pumps is ≤240°C. Hot water centrifugal pumps can be installed in either a stand-alone or horizontal configuration. Here, we will focus on the five most common faults of hot water centrifugal pumps: no water output, insufficient flow rate, noise and vibration, motor overheating, and water leakage, as well as the reasons for these issues and how to resolve them. I. Reasons why a hot water centrifugal pump does not deliver water and how to resolve them: 1. The inlet and outlet valves are not open, the inlet and outlet pipelines are blocked, or the impeller is blocked. The solution is to remove the obstruction. 2. The suction pipe of the hot water pump is leaking air. Tighten all sealing surfaces to remove air. 3. The motor is running in the wrong direction, and its speed is very low due to a missing phase. Adjust the motor direction and secure the motor wiring. 4. The hot water centrifugal pump is not filled with liquid; there is air inside the pump chamber. Open the pump cover or the exhaust valve to release the air. 5. Insufficient water supply for import and export, excessive suction lift, and leakage from the bottom valve. Shut down for inspection and adjustment (this phenomenon often occurs with water supply pipes connected to the grid and those used at a suction lift). 6. Excessive pipeline resistance and improper selection of the centrifugal pump. Reduce the number of bends in the piping and select a different pump. II. Reasons for insufficient flow rate in hot water centrifugal pumps and how to address them: 1. The inlet and outlet valves are not open, the inlet and outlet pipelines are blocked, or the impeller is blocked. The solution is to remove the obstruction. 2. Blockages in the pipes, flow channels, and impeller sections, scale deposition, and insufficient valve opening. Remove the obstruction and readjust the valve opening. 3. The voltage of the hot water centrifugal pump is too low. Voltage stabilization 4, impeller wear. Replace the impeller. 5. Use beyond the rated flow rate. Adjust the flow by closing the outlet valve; 6. The suction lift is too high. Reduce the suction lift. 7. Wear of pump bearings. Replace the bearing. III. Causes of noise and vibration in hot water centrifugal pumps and how to resolve them: 1. Unstable pipeline support. Secure the pipeline. 2. The liquid is mixed with gas. Increase inhalation pressure for exhaust. 3. Cavitation occurs. Reduce the vacuum level. 4. Bearing damage. Replace the bearing. 5. The motor operates with overheating due to overload. Adjust the flow by closing the outlet valve. IV. Causes of motor overheating in hot water centrifugal pumps and how to address them: 1. The flow rate of the hot water centrifugal pump is too high, resulting in overloaded operation. Close outlet valve 2; there is rubbing. Check and rule out. 3. The motor bearings are damaged. Replace the bearing. 4. Insufficient voltage. Voltage stabilization. V. Causes of leakage in hot water centrifugal pumps and how to resolve them: 1. Wear of the pump’s mechanical seal. Replace. 2. The pump body has sand holes or is cracked. Repair by welding or replace. 3. The sealing surface is uneven. Trimming. 4. The mounting bolts are loose. Tighten.