Question

Cavitation in a control valve is caused by:

• A. Process noise
• B. Vibration in pipe
• C. The Von Karman effect
• D. Pressure recovery

Hint:

To prevent cavitation, ensure smooth pressure control and avoid sharp changes in pressure within the valve system. Proper valve sizing and maintenance can help manage pressure recovery.

Answer 1

The Correct Option is D

Cavitation in control valves occurs when the liquid's pressure drops below its vapor pressure, causing the formation of vapor bubbles. The formation and collapse of these bubbles can lead to severe damage to the valve and pipes.
The main cause of cavitation in a control valve is pressure recovery. This refers to the recovery of pressure after a restriction in the flow (such as through the valve), leading to conditions where the liquid pressure drops and bubbles form. These bubbles are then forced to collapse when the pressure increases again, causing cavitation.
Process noise refers to the sound generated by the flow, but it does not directly cause cavitation. Similarly, vibration in the pipe may occur as a result of cavitation, but it is not a direct cause. The Von Karman effect, which is related to vortex shedding, does not directly lead to cavitation in valves.
Therefore, pressure recovery is the correct answer as the primary cause of cavitation in control valves.