All Pumps Machinery Company Limited.

Starting and Stopping of Self-Priming Pump

Before starting the self-priming pumps, there are some preparatory checks to be done

1. Depending on the working condition of the pump, use high-quality calcium-based grease or No. 10 engine oil for lubrication. If the pump is lubricated with grease, it should be regularly refilled with grease in the bearing box. If the pump is lubricated with oil, make sure the oil level is sufficient.

2. Check whether the rotating parts of the self-priming pump are stuck or collide with each other.

3. Check whether the base of the pump and the nuts at the joints are loose.

4. Check the coaxiality and parallelism of the pump shaft and the motor shaft.

5. Check whether there is any air leakage in the suction pipeline, and try to eliminate it if there is.

6. Open the valve of the suction pipeline, and slightly open (not fully open) the outlet control valve.

Starting and operating the self-priming pumps

1. Start the self-priming pump carefully and make sure that the direction of rotation of the pump shaft is correct.

2. Pay attention to any abnormal noise and vibration that occur during operation.

3. Check the pressure gauge and vacuum gauge readings. When the readings have stabilized after fluctuating for some time, it indicates that the pump has been primed and normal fluid transfer can begin.

4. During the priming process of the self-priming pump, pay special attention to the temperature of the water inside the pump. If the priming process takes too long and the water temperature inside the pump gets too high, stop the pump and check the cause.

5. If the liquid temperature inside the self-priming pump is too high and causes difficulty in priming, stop the pump temporarily and use the backflow of liquid in the discharge pipeline to flow back into the pump or directly add liquid to the pump through the liquid filling port to cool the liquid inside the pump. After that, restart the pump.

6. If the self-priming pump experiences strong vibrations and noise during operation, there may be cavitation. There are two reasons for cavitation: excessive flow velocity in the inlet pipeline and excessive suction head. If the flow velocity is too high, adjust the outlet control valve and increase the pressure gauge reading. If the inlet pipeline is blocked, remove the blockage as soon as possible. If the suction head is too high, reduce the installation height of the pump appropriately.

7. When the pump stops running due to some reason and needs to be restarted, open the outlet control valve slightly (not fully closed). This is beneficial for discharging gas during the priming process and ensures that the pump restarts under a relatively light load.

8. Pay attention to checking whether there is any leakage in the pipeline system of the self-priming pump.

Stopping the self-priming pumps

1. First, close the gate valve on the discharge pipeline.

2. Stop the pump from rotating.

3. In cold weather, drain the liquid in the pump body and the bearing box cooling chamber to prevent damage to the pump due to freezing.