What is the primary cause of cavitation in a pump?

Cavitation in a pump primarily occurs due to insufficient inlet flow, which leads to a drop in pressure at the pump’s inlet. When the pressure drops below the vapor pressure of the fluid, cavities or vapor bubbles form. These bubbles collapse violently as they move to areas of higher pressure within the pump, causing significant damage to the pump components, such as erosion and pitting on the impeller and casing.

Maintaining adequate inlet flow is crucial to prevent this phenomenon, as it ensures that the pressure remains above the fluid's vapor pressure throughout the pump’s operational range. Proper system design, including pipeline sizing and ensuring the pump is not placed too high relative to the fluid source, can help mitigate the risk of cavitation.