The most likely cause of a pump quickly becoming noisy and vibrating is?

The most likely cause of a pump quickly becoming noisy and vibrating is?

• A. Cavitation
• B. Air lock
• C. Loose bolts
• D. Overheating

Answer: (A)

Cavitation happens when the suction pressure of the pump drops below the liquid’s vapor pressure, causing tiny vapor bubbles to form at the impeller eye. As these bubbles move into regions of higher pressure inside the pump, they collapse violently, sending shock waves that produce a loud, banging-type noise and cause the pump to vibrate. This onset is often quick when the system demands more flow than the suction can supply, such as at high discharge pressure, a clogged suction line, or when air has entered the line. The rapid, irregular noise and vibration are characteristic of bubble collapse interacting with the impeller and housing, and the condition can also erode parts over time if not addressed. Air lock can create noise and vibration too, but it usually shows up as a loss of prime or reduced flow from trapped air in the suction line, and the symptoms tend to ease after venting the air. Loose bolts would cause persistent mechanical vibration and noise that aren’t tied to the rapid onset pattern caused by bubble collapse. Overheating might produce bearing or motor noise, but it’s not the abrupt, bubble-driven disturbance that cavitation creates.

Cavitation happens when the suction pressure of the pump drops below the liquid’s vapor pressure, causing tiny vapor bubbles to form at the impeller eye. As these bubbles move into regions of higher pressure inside the pump, they collapse violently, sending shock waves that produce a loud, banging-type noise and cause the pump to vibrate. This onset is often quick when the system demands more flow than the suction can supply, such as at high discharge pressure, a clogged suction line, or when air has entered the line. The rapid, irregular noise and vibration are characteristic of bubble collapse interacting with the impeller and housing, and the condition can also erode parts over time if not addressed.

Air lock can create noise and vibration too, but it usually shows up as a loss of prime or reduced flow from trapped air in the suction line, and the symptoms tend to ease after venting the air. Loose bolts would cause persistent mechanical vibration and noise that aren’t tied to the rapid onset pattern caused by bubble collapse. Overheating might produce bearing or motor noise, but it’s not the abrupt, bubble-driven disturbance that cavitation creates.