Pump cavitation problem
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I have a question regarding the pump used for heating water: it’s of the SC80–250 type, with a flow rate of 145 and a head of 77. Its rotation speed is 2900 revolutions per minute. Cavitation occurs as soon as the pump starts operating. When the outlet is narrowed, the sound associated with cavitation decreases, but the flow rate becomes insufficient. I’ve checked all the components inside the pump and they seem to be in good condition. Is there any solution to this problem?
Raise or lower the temperature of the water by adjusting the hot water tank. What is the net positive suction head required on your pump’s nameplate?
Method 1: Raise the suction water level； Method 2: Lower the water temperature ； Method 3: Increase the pressure inside the inhalation container.
Insufficient inhalation volume. If it worked fine before but now isn’t, then check what has changed from before. Anyway, it’s definitely due to an insufficient amount of absorption. As for the reason behind this, it could be high temperature causing vaporization; but after all, this is a hot water pump ； Another possibility is insufficient suction pressure, but if it was working fine before, then that shouldn’t be the issue ； All that’s left is debris in the suction inlet and in the suction pipeline; check for the cause upstream of the suction pipeline.
1. The medium is hot water, and high temperatures make cavitation likely to occur. 2. It is unknown what the diameter of the inlet pipe is, and whether there is a reduction fitting at the pump inlet. 3. It is not clear whether the installation height provides the required net positive suction head
The most effective solution is to lower the temperature~~ I’ve encountered this issue myself while operating
The inlet flow is insufficient, or the inlet pressure is lower than the designed value; increase the pressure
Thank you for the feedback. I understand what you mean. (1) This pump is equipped with a heat exchanger; the surface temperature of the heat exchanger is the same as the temperature at the outlet of the pump’s fluid. Is there any problem with this? The temperature at the outlet of the heat exchanger is low. (2) When the outlet is reduced, the cavitation noise decreases – could it be that the outlet flow rate is too high, exceeding the pump’s maximum flow rate?
Thank you for your advice. The pressure at the inlet is fine, and there are no issues with the pipelines either; it seems to be a temperature problem. I’m not sure how to resolve it, which is why I’m seeking advice from those who are more experienced. There is a heat exchanger on the pump, but the surface temperature of this heat exchanger is as hot as the temperature of the fluid coming out of the pump. However, the temperature at the exit of the heat exchanger is normal and cool. Do you have any suggestions?
In addition to the points mentioned above, cavitation may also occur if the pressure at the pump outlet is controlled too low, meaning that the actual flow rate of the pump is too high.
A water cooler? The jacket is cleaned, and cold water is used to rinse the pump inlet during operation. Additionally, with the outlet valve currently closed, does the flow rate meet the production requirements? Is there a backup pump available? You can try using a backup pump.