3. Start-up and Shutdown
Preparation Before Start-up
1. Manually rotate the motor fan blades. The impeller should rotate smoothly without any jamming.
2. Open the inlet valve and the vent valve to fill the entire pump chamber with liquid, then close the vent valve.
3. Manually rotate the pump to allow lubricating fluid to enter the mechanical seal face.
4. Briefly start the motor to confirm the correct rotation direction.
Start-up and Operation
1. Fully open the inlet valve and close the discharge line valve.
2. Connect the power supply. Once the pump reaches normal operating speed, gradually open the discharge line valve and adjust it to the required operating conditions.
3. Carefully observe the instrument readings and check for shaft seal leakage. Normally, mechanical seal leakage is <3 drops/minute. Check the temperature rise at the motor and bearings to be ≤70°C. If any abnormalities are found, address them immediately.
Shutdown
1. Gradually close the discharge line valve and disconnect the power supply.
2. Close the inlet valve.
3. If the ambient temperature is below 0°C, drain the liquid from the pump to prevent freezing and cracking.
4. If the pump is to be shut down for an extended period, disassemble, clean, and properly store it.
4. Pump Maintenance and Care
Maintenance and Care During Operation
1. The water pipeline must be fully sealed.
2. Do not operate the pump under cavitation conditions for extended periods.
3. Do not operate the pump at full flow rate or allow the motor to run at excessive current for extended periods.
4. Regularly check the pump for excessive current during operation.
5. The pump should be supervised by a designated person during operation to prevent accidents.
6. Lubricate the bearings every 500 hours of pump operation. Motors with a power rating greater than 11KW are equipped with a lubrication device; use a high-pressure oil gun to directly inject oil to ensure the bearings are lubricated and function properly.
7. After prolonged operation, if mechanical wear causes increased noise and vibration in the pump, stop the pump and inspect it. Replace worn parts and bearings if necessary. The general overhaul period for the pump is one year.
Mechanical Seal Maintenance and Care
1. The mechanical seal lubrication system should be clean and free of solid particles.
2. Mechanical seals must not be operated under dry running conditions.
3. Before starting, rotate the pump (motor) several times to prevent sudden starting that could cause the seal ring to break and be damaged.
5. Overall Maintenance and Care
1. Check the centrifugal pump piping and connections for any looseness. Manually rotate the centrifugal pump to test its responsiveness.
2. Add bearing lubricating oil to the bearing housing. The oil level should be at the center line of the oil gauge. Replace or replenish the lubricating oil as needed.
3. Unscrew the priming plug on the centrifugal pump body and fill with priming water (or priming slurry).
4. Close the gate valve on the outlet water pipe and the outlet pressure gauge and inlet vacuum gauge.
5. Briefly start the motor to check if the motor rotation direction is correct.
6. After the centrifugal pump is running normally, open the outlet pressure gauge and inlet vacuum gauge. Once they display appropriate pressure, gradually open the gate valve while simultaneously checking the motor load.
7. Control the flow rate and head of the centrifugal pump within the range specified on the nameplate to ensure the pump operates at its highest power point for maximum energy savings.
8. During operation, the bearing temperature of the centrifugal pump should not exceed 35°C above ambient temperature, and the maximum temperature should not exceed 80°C.
9. If any abnormal noise is detected in the centrifugal pump, stop the pump immediately and investigate the cause.
10. When stopping the centrifugal pump, first close the gate valve and pressure gauge, then stop the motor.
11. Change the lubricating oil after 100 hours of operation during the first month. Thereafter, change the oil every 500 hours.
12. Regularly adjust the packing gland to ensure normal dripping from the packing chamber (dripping is ideal).
13. Periodically check the wear of the shaft sleeve; replace it promptly when significant wear is observed.
14. When using a centrifugal pump in cold winter, after stopping the pump, unscrew the drain plug at the bottom of the pump body to drain the medium completely. This prevents freezing and cracking.
15. If the centrifugal pump is to be out of service for an extended period, it must be completely disassembled, dried, and all rolling parts and joints coated with grease before being properly reassembled and stored.