What is cavitation in pumping systems?

• A. The formation of bubbles in low-pressure regions around the impeller.
• B. The buildup of sediment inside the pump housing.
• C. The overheating of the motor windings.
• D. The corrosion of the pump casing due to chemicals.

Answer: (C)

Cavitation in pumping systems is the formation of vapor bubbles in a liquid when local pressure drops below the liquid’s vapor pressure, typically occurring in low-pressure regions around the impeller. As the pump creates suction and accelerates flow, the suction side and areas near the blades can experience reduced pressure. When this pressure falls below the liquid’s vapor pressure, tiny bubbles form. As these bubbles are carried into higher-pressure regions, they collapse violently, sending shock waves that can erode impeller blades, cause vibration and noise, and reduce pump head and efficiency. This is a fluid-dynamic issue tied to pressure and vaporization, not to sediment buildup, motor overheating, or chemical corrosion.