What typically causes cavitation in a centrifugal pump?

Cavitation in a centrifugal pump occurs primarily due to the formation of vapor pockets in the flow stream. This phenomenon happens when the pressure in a fluid drops below its vapor pressure, leading to the formation of bubbles or vapor cavities. When these vapor pockets move into areas of higher pressure within the pump, they collapse violently, which can cause significant damage to the pump components, including impellers and casings.

This situation is often triggered by insufficient suction pressure, high fluid temperatures that reduce pressure, or an unexpected drop in flow rates. The resulting collapse of these bubbles can create shock waves that erode the metal surfaces around the area where cavitation occurs. Understanding this process is crucial for preventing damage and ensuring efficient operation of centrifugal pumps.

While high temperatures in the fluid, poor pump alignment, and excessive fluid viscosity can impact pump performance and efficiency, they are not the direct causes of cavitation like vapor pockets are. High temperatures can indeed reduce the fluid's density and affect pressure conditions, but the key factor causing cavitation is the formation of vapor pockets themselves.