Which term describes the sudden pressure surge in a piping system commonly caused by rapid valve closure?

• A. Back Siphonage
• B. Water Hammer
• C. Emitter Clogging
• D. System Leakage

Answer: (B)

When a valve is closed quickly, the moving water has momentum and resists stopping. The result is a pressure spike that travels through the pipe, called water hammer. The water’s momentum, combined with the pipe’s elasticity, creates a shock wave that can cause loud banging, vibration, and potential damage to joints, fittings, and equipment. This phenomenon is common in irrigation systems when valves shut rapidly or pumps start/stop suddenly.

Back siphonage isn’t about a pressure surge from closing a valve; it’s reverse flow caused by negative pressure in the supply line. Emitter clogging is a downstream blockage issue, not a pressure wave. System leakage describes pressure loss due to leaks, not a surge.