Shock wave created by a fast closing valve?

Shock wave created by a fast closing valve?

• A. Water hammer
• B. Vibration surge
• C. Pressure spike
• D. Hydraulic pulse

Answer: (A)

When a valve closes rapidly, the moving water wants to keep flowing. That inertia forces the water to decelerate abruptly, creating a sudden, high-pressure wave that travels through the pipe. This shock wave is the water hammer. It propagates at the speed of sound in the liquid, can reflect off ends and fittings, and often causes banging sounds and potential damage if not controlled with slower valve closures, air chambers, or other mitigation methods. Other terms describe aspects of the same transient, but water hammer is the standard name for this specific shock-like pressure surge caused by rapid valve closure. A simple pressure spike describes the result, and hydraulic pulse is a general phrasing for a transient, but the well-established phenomenon is water hammer.

When a valve closes rapidly, the moving water wants to keep flowing. That inertia forces the water to decelerate abruptly, creating a sudden, high-pressure wave that travels through the pipe. This shock wave is the water hammer. It propagates at the speed of sound in the liquid, can reflect off ends and fittings, and often causes banging sounds and potential damage if not controlled with slower valve closures, air chambers, or other mitigation methods.

Other terms describe aspects of the same transient, but water hammer is the standard name for this specific shock-like pressure surge caused by rapid valve closure. A simple pressure spike describes the result, and hydraulic pulse is a general phrasing for a transient, but the well-established phenomenon is water hammer.