What leads to cavitation in pumps?

Cavitation in pumps occurs when the pressure in a localized area drops below the vapor pressure of the fluid being pumped. When this happens, vapor bubbles form in the liquid. As these bubbles move through the pump and enter areas of higher pressure, they collapse violently, which can cause significant damage to the impeller and other components due to the shock waves produced during bubble collapse. This phenomenon can lead to reduced efficiency and potential failure of the pump.

Understanding this process highlights the importance of maintaining appropriate operating conditions to ensure that local pressures do not fall below vapor pressure. Factors such as pump design, fluid properties, flow rates, and even elevation changes can influence pressure drops that lead to cavitation.

The other options, while related to pump operation, do not directly cause cavitation. Increased viscosity could affect the flow characteristics and might contribute to other issues, and excessive heat could lead to changes in fluid properties (like increasing vapor pressure) but does not directly induce cavitation. Inadequate seals primarily affect leakage and overall pump operation but are not a cause of cavitation.