What is the term used for the surge in pressure caused by sudden valve closure?

The term "water hammer" specifically refers to the phenomenon of a sudden surge in pressure that occurs when a fluid in motion is forced to stop or change direction abruptly, often due to the sudden closure of a valve. This rapid deceleration creates a shock wave that travels through the fluid, leading to a significant increase in pressure, commonly referred to as a hydraulic shock or water hammer effect.

In plumbing and piping systems, water hammer can generate loud banging noises, vibration, and potential damage to pipes and fixtures if not managed properly. Understanding this concept is essential for maintenance workers, as it helps them recognize the implications of quick valve closures and implement measures to mitigate this issue, such as installing air chambers or water hammer arrestors in the system.

While the term "hydraulic shock" is often used interchangeably with water hammer, in this context, it specifically highlights the phenomenon that causes the pressure surge due to the instant change in flow dynamics. Other terms like “pressure surge” and “flow reversal” point to different concepts and events within fluid dynamics, but they do not encapsulate the specific result of sudden valve closure as accurately as "water hammer" does.