What can cause cavitation in pumps?

Cavitation in pumps occurs when the pressure of the liquid within the pump falls below its vapor pressure, causing the formation of vapor bubbles. Excessive suction lift is a primary cause of cavitation because it can lead to an insufficient pressure at the pump's inlet. When the suction lift is too high, the pump has to work harder to draw the fluid in, which can decrease the pressure sufficiently to create vapor pockets. These pockets collapse violently when they move into higher pressure areas within the pump, which can lead to damage and reduce efficiency.

In contrast, excessive heat can alter the viscosity of the pumped fluid but doesn't directly relate to the mechanisms causing cavitation. Inadequate flow rates typically affect the pump performance but are more associated with potential operational issues rather than being a direct trigger for cavitation itself. Submersible operation usually helps to maintain adequate pressure, as the pump is designed to operate underwater, where it’s less likely to encounter vapor pressure issues. Therefore, excessive suction lift is the most accurate choice for causing cavitation in pumps.