What is the most likely cause of a pump becoming noisy and vibratory?

Cavitation in a pump occurs when there is a drop in pressure within the pump, leading to the formation of vapor bubbles. When these bubbles collapse or implode, they create intense shock waves that can cause noise and vibration. This phenomenon usually occurs when the fluid’s pressure drops below its vapor pressure, which can happen due to factors such as high fluid temperature, low inlet pressure, or high flow rates. The resulting noise and vibration from cavitation can be severe enough to damage the pump components over time.

While other options may cause issues in a pump, they typically do not produce the same distinctive noise and vibration associated with cavitation. Worn bearings might lead to some level of vibration, but it is generally a different kind of noise and often accompanied by changes in the wear patterns of the bearings. Improper alignment can also cause vibrations, but these are usually more persistent and less intense than those caused by cavitation. Low fluid levels can lead to pump cavitation, but it is the cavitation itself that is directly responsible for generating the characteristic noises and vibrations.