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3 Tips for Handling a Water Hammer

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Have you heard your home’s plumbing make a banging or knocking sound once you shut off a faucet? This phenomenon is known as a water hammer. It’s the result of a pressure surge that propagates through a piping system when water in motion is forced to change direction or stop abruptly. Also known as hydraulic shock, this clamor can actually put undue water pressure on your plumbing and cause significant damage. Here are just a few ways to handle a water hammer if this shock wave happens in your household.

1. Air Chambers in Your Plumbing


If you’re wondering how to recognize a water hammer compared to just normal noises from your fixtures, you’ll be able to recognize the loud clanking and associate it with your water use habits. If you’ve noticed an additional length of the pipe coming from the supply lines of your plumbing system, these are air chambers meant to assist with your water hammer problem. Filled with air or gas, each pipe acts as a shock absorber for the water that comes to a sudden halt. Air compresses; water does not.

This means that the air in the chamber acts as a cushion for the water. These chambers can fill with water over time, and may occasionally need to be drained. While it may be tempting to tackle your water supply line and corresponding air chambers, this requires advanced plumbing skills. A licensed plumber will make sure that this issue and any trouble with your water pipes are properly cared for.

2. Water Hammer Arrestors


A water hammer arrestor improves upon the idea of the air chamber by adding a chamber filled with gas. Water hammer arrestors absorb the sudden jolt of increased water pressure when a valve shuts off. Most arresters are easy for homeowners to install, featuring screw-type connectors that attach between a water-supply one and a shut-off valve. Be sure to install two of these arresters: One for your hot water supply line and one for cold water. This will help with any water-related appliances in your household, including your washing machine and dishwasher.

These water hammer arrestors come with a piston or diaphragm that creates a seal. In plumbing, a diaphragm is a flexible disc that responds to a pressure wave to form a seal. Coming in various kinds of materials, the diaphragm stops fluid flow in the pipe system. A water hammer arrestor is often spliced into the point where the water supply hose meets up with a shutoff valve.

3. Adjust Valves and Insulate


Excessive water pressure in your pipes can cause a water hammer, in which case emptying an air chamber of water or installing an arrester is just a temporary fix. Homeowners can regulate water pressure on a troublesome valve. Depending on the manufacturer, some valves have a handle to adjust for surge pressure, while others require a screwdriver. A setting below 50 pSI, or pounds per square inch, is best for most homes. This also promotes water conservation and prolongs the life of appliances and fixtures like toilets.

While this could be a job for a homeowner or a licensed plumber, you can also prevent the occurrence of a water hammer by cushioning water supply lines with pipe insulation. These foam tubes cost just a few bucks and are designed to fit around supply lines to keep them from freezing. These also act as a support system for loose pipes. Be sure to address the cause of a water hammer as soon as possible though. Don’t let your plumbing suffer, and hurt your bottom line down the line.