1. Inspection before starting the centrifugal pump
1) After the motor maintenance, check whether the rotation direction of the motor is correct before connecting the coupling.
2) Check whether the installation of pump inlet and outlet pipelines, auxiliary pipelines, flanges, and valves meets the requirements, whether the anchor bolts and ground wires are in good condition, and whether the coupling is installed properly.
3) Check the turning gear to see if it rotates normally.
4) Check if the lubricating oil level is normal, add oil if there is no oil, and inspect the oil properties of the lubricating oil (grease).
5) Open all cooling water valves and check if the pipelines are unobstructed. Note that the cooling water should not be too large or too small. If it is too large, it will cause waste, and if it is too small, the cooling effect will be poor. Generally, the cooling water flow should be linear.
6) Open the inlet valve of the pump, close the outlet valve of the pump, and open the pressure gauge hand valve.
7) Check the sealing condition of the pump and the opening of the oil seal.
Attention: The hot oil pump should be preheated evenly before starting.
2. Startup of centrifugal pump
1) Fully open the inlet valve, close the outlet valve, and start the motor.
2) When the outlet pressure of the pump is greater than the operating pressure, check that all parts are operating normally and gradually open the outlet valve.
3) When starting the motor, if it cannot be started or there is abnormal noise, the power should be immediately cut off for inspection, and the fault should be eliminated before starting.
4) When starting, be careful not to face the coupling to prevent flying out and injuring people.
3. Shutdown operation of centrifugal pump
1) Slowly close the outlet valve of the pump.
2) Cut off the power supply to the motor.
3) Close the pressure gauge manual valve.
4) After parking, do not immediately stop the cooling water. Wait until the temperature of the pump drops below 80 ℃ before stopping the water.
5) As needed, close the inlet valve and empty the pump body.
4. Operation and maintenance of centrifugal pump during operation
When the centrifugal pump is operating normally, the pump operator should carefully inspect the following:
1) Check the outlet pressure, flow rate, current, etc. of the pump, do not operate beyond the load, and accurately record parameters such as current and pressure.
2) Listen to the sound, distinguish the operating sound of the pump and motor, and determine if there are any abnormalities.
3) Check the vibration of the pump, motor, and pump seat. If the vibration is severe, replace the pump for inspection.
4) Check the temperature of the motor casing and the bearing box of the pump. The temperature of the bearing box should not exceed 65 degrees, and the temperature of the motor should not exceed 95 degrees.
5) Ensure the normal quality of lubricating oil and the liquid level of the lubricating oil tank. Lubricating oil tank level, if there is a scale, the scale shall prevail; There is a sight glass (oil gauge) without a scale line, and the oil level should be maintained between 1/3 and 1/2. At normal oil level, the leakage of lubricating oil should not exceed 5 drops/minute, and oil should be injected under pressure according to the machine instructions.
6) Check the pump seal and all flanges, plugs, cooling water, and sealing oil joints for leaks.
7) Check the standby condition of the backup pump and turn it once a day.
5. Switching operation of centrifugal pump
To ensure that the flow rate, pressure, and other parameters do not change or fluctuate when switching pumps, it is best for two people to operate simultaneously.
1) Make preparations before starting the pump.
2) One person first starts the standby pump, and after the centrifugal pump runs smoothly and normally, slowly opens the outlet valve. At this time, with the opening of the pump outlet valve, the pressure of the pump outlet valve slightly decreases, but the motor current increases. At the same time, the other person slowly closes the outlet valve that needs to stop the pump. When the flow rate of the pump to be operated is large enough, the outlet valve that needs to stop the pump is completely closed, the power is cut off, and then the pump is stopped normally.
