A condition which can cause cavitation in a pump is?

Cavitation in a pump occurs when the pressure at the pump inlet falls below the vapor pressure of the liquid, leading to the formation of vapor bubbles. When these bubbles move into higher pressure areas within the pump, they collapse violently, causing potential damage to the pump components.

An air leak on the suction side of the pump introduces air into the system, which decreases the static pressure. This drop in pressure can cause the liquid's pressure to fall below its vapor pressure, leading to cavitation. Therefore, an air leak directly impacts the pressure conditions necessary to prevent cavitation.

In contrast, clear water being pumped does not inherently cause cavitation. The composition of the liquid (clear water in this case) is not a direct factor in cavitation; rather, it’s the pressure conditions that matter. A fully opened suction valve typically allows for maximum flow and may reduce the likelihood of cavitation by maintaining adequate pressure. Operating within the design curve ensures the pump performs optimally without risking pressure drops that lead to cavitation.