What is the best method to prevent water hammer?

What is the best method to prevent water hammer?

• A. Keep hoses taut
• B. Increase pipe diameter
• C. Open rapidly
• D. Open and close valves and nozzles slowly

Answer: (D)

Water hammer happens when the flow in the piping is changed too quickly, sending a pressure surge through the system as momentum is abruptly halted or redirected. The most reliable way to avoid that surge is to make valve and nozzle movements gradual. Opening and closing them slowly slows how fast the flow changes, so the resulting pressure rise stays within what the system can safely handle. This directly addresses the cause of the problem—rapid velocity change—and protects hoses, fittings, and pumps from shock. Quick opening or closing would produce the opposite effect, creating the very surge you’re trying to prevent, and factors like hose tension or simply increasing pipe size don’t offer an immediate, practical solution during operation.

Water hammer happens when the flow in the piping is changed too quickly, sending a pressure surge through the system as momentum is abruptly halted or redirected. The most reliable way to avoid that surge is to make valve and nozzle movements gradual. Opening and closing them slowly slows how fast the flow changes, so the resulting pressure rise stays within what the system can safely handle. This directly addresses the cause of the problem—rapid velocity change—and protects hoses, fittings, and pumps from shock. Quick opening or closing would produce the opposite effect, creating the very surge you’re trying to prevent, and factors like hose tension or simply increasing pipe size don’t offer an immediate, practical solution during operation.