2016-12-3 Quiz Questions

1. Regularly check the readings of the pressure gauge, vacuum gauge, and ammeter; if any abnormalities are detected, the cause should be identified and resolved promptly； 　 2. Regularly check the lubricant level to keep it within the specified range, and periodically inspect the quality of the lubricant; if any changes are detected, it should be replaced promptly with the appropriate grade as required ； 　　 3. Regularly monitor the supply of lubricating oil, sealing oil, and cooling water ； 　　 4. Regularly check the tightness of the foundation bolts of the centrifugal pump and motor, the temperature of the pump body and bearings, as well as the sound emitted during pump operation; address any issues promptly if they are detected ； 　　 5. For centrifugal pumps with complex structures and a high degree of automation, they must be started, maintained, and stopped in accordance with the relevant operating procedures; the operating methods must not be changed arbitrarily without scientific basis or experimental verification.

1. Are there any abnormalities in the outlet pressure and flow rate?； 2 Motor current ； 3. Are there any unusual noises? ； 4. Bearing vibration and temperature ； 5. Lubricant quality and quantity ； 6. Condition of the pump inlet filter ； 7. Is the cooling water flowing smoothly? ； 8. Shaft seal temperature and leakage condition ； 9. Are there any leaks elsewhere? ； 10. The inlet liquid level is sufficient.

1 Startup: The following preparations should be made before starting: (1) Check the condition of the water pump equipment. (2) The bearings are properly filled with oil, the oil level is normal, and the oil quality is satisfactory. (3) Open all the inlet valves of the centrifugal pump. (4) Fill the pump with water or use a vacuum pump to draw in water (excluding backflow), then open the vent valve to release air. (5) Check for leaks at the shaft seal; a slight dripping from the packing seal is acceptable. (6) The motor rotation direction is correct. 2 Operation: During operation, routine inspections are carried out, and the inspection covers four aspects: 1. Inspection of bearings (1) The bearing temperature should not exceed 75°C. (2) The bearing chamber must not be flooded with water or contaminants, and the oil must not become emulsified or darken. (3) When a rolling bearing is lubricated with thin oil, the oil level should not be below the center line of the oil gauge. (4) Are there any abnormal noises? Abnormal sounds usually occur when rolling bearings are damaged. Check whether the readings of the vacuum gauge, pressure gauge, and ammeter are normal. (1) The pointer of the vacuum gauge should not swing excessively; excessive movement can cause vaporization at the pump inlet. Additionally, the reading on the vacuum gauge should not be too high, as this may indicate that the inlet valve is blocked or stuck, or that the water level in the suction tank has dropped. (2) If the reading on the outlet pressure gauge is too low, it may be due to severe wear of the sealing ring and guide vane sleeve. The gap between the stator and rotor is too large, or the outlet valve is opened too wide, resulting in high flow rate and low head pressure. (3) If the ammeter reading is too high, it may be due to a high flow rate, or friction occurring between the stator and rotor components. 3. Does the pump unit generate excessive vibration? The reasons for this vibration include: (1) Misalignment of the shaft axes of the water pump and the motor. (2) The foot bolts of the water pump or motor are loose, or the foundation is not solid. (3) Unbalanced rotor mass. (4) When the pump operates at low flow rates, radial forces, backflow, and cavitation occur. 4. Is the sealing function working properly? (1) A K-type dynamic seal should not leak when it is operating normally. (2) In cases with a cooling water system, check whether the water flow is normal.

1. Monitor the current and outlet pressure of the operating pump. 2. Check the oil level, oil quality, and cooling water. 3. Measure the bearing temperature and vibration of the operating pump. 4. Check whether the anchor bolts of the operating pump and motor are loose

The following maintenance tasks should be attended to while the pump is in operation: 1. Regularly check the readings of the pressure gauge, vacuum gauge, and ammeter; if any abnormalities are detected, the cause should be identified and resolved promptly； 2. Regularly check the lubricant level to keep it within the specified range, and periodically inspect the quality of the lubricant; if any changes are detected, it should be replaced promptly with the appropriate grade as required ； 3. Regularly monitor the supply of lubricating oil, sealing oil, and cooling water ； 4. Regularly check the tightness of the foundation bolts of the centrifugal pump and motor, the temperature of the pump body and bearings, as well as the sound emitted during pump operation; address any issues promptly if they are detected ； 5. For centrifugal pumps with complex structures and a high degree of automation, they must be started, maintained, and stopped in accordance with the relevant operating procedures; the operating methods must not be changed arbitrarily without scientific basis or experimental verification. 1. Strictly abide by safety regulations and the shift handover procedures; it is strictly prohibited for personnel other than those assigned to operate the pumps from handling the equipment, in order to prevent accidents. 2. It is strictly prohibited to wipe the equipment while it is in operation; various tools and other items must not be placed on the pump or motor. 3. Before starting the pump, it is necessary to fill the pump with liquid until liquid emerges from the vent nozzle at the top of the pump casing. 4. Close the outlet valve before starting the pump. 5. Before starting the centrifugal pump, turn it over manually and apply lubricant. Pay attention to the cooling condition, open the inlet valve, start the motor, and once the pressure gauge shows stability, open the outlet valve. 6. Regularly check whether the readings of the pressure gauge and ammeter are normal; if any abnormalities are detected, the cause should be identified promptly and resolved as soon as possible. 7. Regularly check the lubricating oil and seal oil levels to keep them within the specified range; periodically inspect the quality of the lubricating oil, and replace it with the appropriate grade as soon as any abnormalities are detected. 8. Regularly monitor the supply of lubricating oil, seal oil, and cooling water. 9. Regularly check the tightness of the anchor bolts connecting the centrifugal pump to the motor, as well as the temperature of the pump body and bearings and the sound emitted during pump operation; address any issues promptly if they are detected. 10. Centrifugal pumps with complex structures and a high degree of automation must be started, maintained, and stopped in accordance with the relevant operating procedures; the operating methods should not be changed arbitrarily without scientific basis or proven experience.

1. Regularly check the readings of the pressure gauge, vacuum gauge, and ammeter; if any abnormalities are detected, the cause should be identified and resolved promptly； 　　2. Regularly check the lubricant level to keep it within the specified range, and periodically inspect the quality of the lubricant; if any changes are detected, it should be replaced promptly with the appropriate grade as required ； 　　3. Regularly monitor the supply of lubricating oil, sealing oil, and cooling water ； 　　4. Regularly check the tightness of the foundation bolts of the centrifugal pump and motor, the temperature of the pump body and bearings, as well as the sound emitted during pump operation; address any issues promptly if they are detected ； 　　5. For centrifugal pumps with complex structures and a high degree of automation, they must be started, maintained, and stopped in accordance with the relevant operating procedures; the operating methods must not be changed arbitrarily without scientific basis or experimental verification.

Precautions for operating a centrifugal pump include: 1. Pay attention to the motor current and whether the operating noise is normal. 2. The temperature of the motor or pump bearings shall not be 35°C higher than the ambient temperature, and the maximum temperature shall not exceed 75°C. 3. Is there any sound of metal friction from the pump impeller, pump bearings, or motor bearings? 4. Whenever the system stops for any reason, the equipment must be inspected, repaired, and maintained. Experimental restarts must not be attempted until the fault has been fully identified and resolved. 5. Regularly check whether the temperatures of all bearings are normal. 6. Pay attention to observing the operation of the equipment, and check whether the vibration and noise are normal. 7. Pay attention to checking whether the screws in various parts are loose. 8. Check whether the motor is running properly. 9. Check whether the current is within the normal range. 10. Pay attention to checking whether the pipeline is leaking grout. 11. Eliminate idling. 12. During operation, regularly check the pressure and flow rate of the shaft seal water. 13. For sealed systems that use a secondary impeller in combination with packing, it is necessary to adjust the tightness of the packing gland as needed and replace the packing periodically, to ensure that a small amount of clean water continues to flow past the shaft. 14. Regularly check the condition of the brackets, as well as the cleanliness and level of the lubricating oil. To prevent the bearings from overheating, it is necessary to use cooling water.

1. Bearing inspection: (1) The bearing temperature should not exceed 75°C. (2) The bearing chamber must not be flooded with water or contaminants, and the oil must not become emulsified or darken. (3) When a rolling bearing is lubricated with thin oil, the oil level should not be below the center line of the oil gauge. (4) Are there any abnormal noises? Abnormal sounds usually occur when rolling bearings are damaged. Check whether the readings of the vacuum gauge, pressure gauge, and ammeter are normal. (1) The pointer of the vacuum gauge should not swing excessively; excessive movement can cause vaporization at the pump inlet. Additionally, the reading on the vacuum gauge should not be too high, as this may indicate that the inlet valve is blocked or stuck, or that the water level in the suction tank has dropped. (2) If the reading on the outlet pressure gauge is too low, it may be due to severe wear of the sealing ring and guide vane sleeve. The gap between the stator and rotor is too large, or the outlet valve is opened too wide, resulting in high flow rate and low head pressure. (3) If the ammeter reading is too high, it may be due to a high flow rate, or friction occurring between the stator and rotor components. 3. Does the pump unit generate excessive vibration? The reasons for this vibration include: (1) Misalignment of the shaft axes of the water pump and the motor. (2) The foot bolts of the water pump or motor are loose, or the foundation is not solid. (3) Unbalanced rotor mass. (4) When the pump operates at low flow rates, radial forces, backflow, and cavitation occur. 4. Is the sealing function working properly? (1) A K-type dynamic seal should not leak when it is operating normally. (2) In cases with a cooling water system, check whether the water flow is normal.

1. Strictly abide by safety regulations and the shift handover procedures; it is strictly prohibited for personnel other than those assigned to operate the pumps from handling the equipment, in order to prevent accidents. 2. It is strictly prohibited to wipe the equipment while it is in operation; various tools and other items must not be placed on the pump or motor. 3. Before starting the pump, it is necessary to fill the pump with liquid until liquid emerges from the vent nozzle at the top of the pump casing. 4. Close the outlet valve before starting the pump. 5. Before starting the centrifugal pump, turn it over manually and apply lubricant. Pay attention to the cooling condition, open the inlet valve, start the motor, and once the pressure gauge shows stability, open the outlet valve. 6. Regularly check whether the readings of the pressure gauge and ammeter are normal; if any abnormalities are detected, the cause should be identified promptly and resolved as soon as possible. 7. Regularly check the lubricating oil and seal oil levels to keep them within the specified range; periodically inspect the quality of the lubricating oil, and replace it with the appropriate grade as soon as any abnormalities are detected. 8. Regularly monitor the supply of lubricating oil, seal oil, and cooling water. 9. Regularly check the tightness of the anchor bolts connecting the centrifugal pump to the motor, as well as the temperature of the pump body and bearings and the sound emitted during pump operation; address any issues promptly if they are detected. 10. Centrifugal pumps with complex structures and a high degree of automation must be started, maintained, and stopped in accordance with the relevant operating procedures; the operating methods should not be changed arbitrarily without scientific basis or proven experience.