What Is Cavitation?

It often sounds like gravel moving through the casing. The collapsing bubbles can pit the impeller, damage the casing, raise vibration, and reduce performance. Cavitation is not normal solids noise.

Low suction pressure is a common cause. Possible reasons include a low wet-well level, plugged suction, closed valve, high liquid temperature, too much flow, or poor suction design. A worn pump may have other noises that sound similar.

If cavitation is suspected, record suction and discharge conditions, flow, level, speed, and sound. Follow the procedure for reducing load or stopping the pump. Do not keep running damaged equipment until it fails. Find the suction or operating cause.

Cavitation damage often looks like rough pitting instead of smooth wear. Save pictures and inspection notes when the pump is opened. Comparing the damage with operating trends can show whether the cause is getting worse or whether a past correction worked.