How to detect and handle pump cavitation?

There is a crackling sound inside the pump, and the outlet pressure gauge shows fluctuations or very low pressure

There is significant noise at the pump head, and the outlet pressure gauge is unstable, showing large fluctuations. In the event of such a problem, stop the pump, refill it, close the outlet valve and open the outlet vent to release all the gas from within the pump chamber until material begins to flow out. Then restart the pump; if the outlet pressure remains stable without fluctuations and meets the requirements of the process, the pump can be used normally.

Low pump outlet pressure, low flow rate, fluctuating current, abnormal noises inside the pump； Just stop the pump, refill it, and then restart it; if that doesn’t work, check whether the inlet filter screen as well as the inlet pipelines and valves are clogged.

The pump vibrates, produces loud noises, the outlet pressure is unstable with large fluctuations, and the current is also low and fluctuates. This situation is usually caused by cavitation; simply stop the pump, refill it, and then restart it.

When the pump is evacuated, it emits noise, and the noise is irregular; in addition, when looking at the pressure gauge, its reading fluctuates significantly up and down.

The outlet pressure is low or absent, and the pump body vibrates heavily. Drainage treatment. Hazardous liquids are vented through a flare stack.

Judgment: 1. The pressure gauge reading fluctuates significantly； 2、Significant fluctuations in traffic ； 3. Fluctuations in current display ； 4. The self-priming tank/pipeline is hot ； 5. No sound, or only a very slight sound, of fluid flow within the pipeline ； 6. The pump body vibrates significantly, produces loud and irregular noises. Solution: Handle it according to the specific circumstances. 1. Pumps equipped with a self-priming tank may experience vacuum conditions at startup, such as sewage pumps or sludge pumps. The following issues might be responsible for this: no liquid level in the self-priming tank – restarting the pump after filling it with liquid usually resolves the problem; clogged inlet filter – cleaning the inlet filter will help; mechanical problems with the pump – opening and closing the outlet valve rapidly several times to release air can restore normal operation. 2. It is essential to ensure that the inlet valve is open before starting the pump. 3. If a pump suddenly experiences vacuum conditions during operation, check whether the upstream valve has malfunctioned and closed, or if the supply of oil to the upstream equipment has been interrupted. Changes in the properties of the crude oil being processed can also cause such vacuum conditions. In such cases, the operator on site should reduce the flow rate at the pump’s outlet and investigate whether there are any abnormalities in the process; if necessary, the pump should be shut down. The operator inside the control room should determine the cause as quickly as possible and give clear instructions to the operator on site

Pump evacuation is definitely caused by unstable pressure at the pump outlet, loud vibration noises from the pump, unstable flow rate, and a low current consumption of the pump； The principle is to remove the liquid inside the pump: one method is to switch the pump or turn it on and off repeatedly, while keeping the pump outlet closed to allow the liquid to be expelled; if conditions permit, the pump can be emptied directly

When a pump becomes vacuumed, it usually produces loud noises and vibrations, and the pressure gauge at the outlet shows no reading. When dealing with this issue, it is first necessary to determine what type of pump it is. If it is a centrifugal pump, the outlet valve should be closed, the power should be turned off, the pump should be refilled with fluid and then started again. If it is a screw pump, the power should be turned off first; once it is confirmed that the material supply to the pump’s inlet is adequate and that the pump operates properly, it can then be started