Expert Guide How to Stop Water Hammer

Water hammer is a common plumbing problem that can cause significant damage to your system if left unchecked. It’s characterized by a loud banging or hammering noise that often occurs when you turn off a faucet or appliance. Understanding the causes, effects, and prevention methods of water hammer is crucial for maintaining a healthy and efficient plumbing system.

What Causes Water Hammer?

Water hammer is caused by sudden changes in water velocity within your pipes. This can happen when:

• Valves are closed quickly: This sudden stoppage can create a pressure wave that travels through the pipes.
• Pumps start or stop: These rapid changes in flow can also generate pressure surges.
• Check valves malfunction: If a check valve doesn’t function properly, it can allow water to flow backwards, causing pressure fluctuations.

The Dangers of Water Hammer

Water hammer can lead to a variety of problems, including:

• Pipe damage: The pressure surges can weaken pipes over time, leading to leaks and bursts.
• Equipment damage: Water hammer can also damage appliances and fixtures, such as water heaters, washing machines, and toilets.
• Noise and vibration: The loud banging noises can be disruptive and even annoying.

Preventing Water Hammer

Water hammer, the loud banging noises in your pipes, can be both annoying and damaging and need emergency repair. By understanding its causes and taking preventative measures, you can significantly reduce the risk of this issue.  

Valve Selection: A Crucial Factor

One of the most effective ways to prevent water hammer is by selecting the right valves during the planning phase of your plumbing system.  

• Pneumatically or Electrically Actuated Valves: These valves offer precise control over opening and closing times, minimizing pressure surges.
• Angle Seat or Full-Way Valves: These valves, when configured correctly, can help prevent water hammer by closing against the flow direction of the liquid.  
• Diaphragm Valves: While diaphragm valves can be used regardless of flow direction, they may experience temporary external leakage during water hammer events. However, if the diaphragm remains undamaged, the valve can continue to function normally.  

Example: For pneumatically actuated process valves, consider using Type 2000 valves that close against the flow velocity of the liquid.  

Additional Prevention Tips

• Install Water Hammer Arrestors: These devices absorb pressure surges and help prevent damage to your pipes.  
• Use Air Chambers: Air chambers can cushion pressure waves and reduce the impact of water hammer.  
• Avoid Rapid Valve Closure: Close valves slowly to prevent sudden changes in water velocity.  
• Maintain Your Plumbing System: Regular maintenance can help identify and address potential issues that could contribute to water hammer.

Retrofitting Existing Systems

If you’re dealing with an existing system, there are still steps you can take to reduce the risk of water hammer:

• Replace individual valves with ones that have adjustable opening and closing speeds.
• Install flow restrictors to reduce the volume flow rate of the liquid through the valve.  
• Slow down the closing speed of pneumatic process valves by restricting the flow of pneumatic air.
• Use electromotive actuators with adjustable opening and closing speeds.
• Limit speed changes in the system.

While these preventive measures can significantly reduce the risk of water hammer, it’s always a good idea to consult with a professional plumber for a thorough assessment of your specific situation. They can assess your situation and recommend appropriate solutions to prevent further damage or find the right replacement in case maintenance is impossible.