Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by __________.

Correct Answer: Option A — cavitations

Cavitation occurs when local pressure drops below the fluid's vapor pressure, forming vapor bubbles that collapse violently against the impeller surface. This implosion causes mechanical fatigue and pitting, typically appearing on the suction side of the impeller vanes. It is a common cause of material degradation in high-velocity centrifugal pumps.