In a system with steam and water counterflow, which option represents the water hammer cause?

In a system with steam and water counterflow, which option represents the water hammer cause?

• A. Pressurized water entering a vertical steam-filled pipe (steam pocket collapse)
• B. Cause of Water Hammer
• C. Steam and water counterflow in a horizontal pipe
• D. Hot water entering a low pressure line

Answer: (A)

In a steam–water system, water hammer happens when liquid water under pressure enters a region that is filled with steam, causing rapid condensation and the collapse of a steam pocket. In a vertical pipe that’s already steam-filled, a slug of pressurized water entering can push into the steam and force the pocket to collapse quickly. This sudden collapse and the continued momentum of the water create a high-pressure surge that travels through the system—the water hammer. That specific scenario best captures the mechanism behind the hammer in a counterflow steam–water setup. The other descriptions don’t pinpoint the cause. Merely noting steam and water counterflow or describing hot water entering a low-pressure line doesn’t describe the rapid steam pocket collapse and the resulting pressure surge that characterizes water hammer in this context.

In a steam–water system, water hammer happens when liquid water under pressure enters a region that is filled with steam, causing rapid condensation and the collapse of a steam pocket. In a vertical pipe that’s already steam-filled, a slug of pressurized water entering can push into the steam and force the pocket to collapse quickly. This sudden collapse and the continued momentum of the water create a high-pressure surge that travels through the system—the water hammer. That specific scenario best captures the mechanism behind the hammer in a counterflow steam–water setup.

The other descriptions don’t pinpoint the cause. Merely noting steam and water counterflow or describing hot water entering a low-pressure line doesn’t describe the rapid steam pocket collapse and the resulting pressure surge that characterizes water hammer in this context.