3 Types of Water Hammer Arrestors Explained

While a water hammer makes annoying sounds, it can also damage pipes, so water hammer arrestors are vital additions to your home's plumbing system. A water hammer can lead to perforations in water pipes or bursts at pipe seams, causing water damage and possible flooding in bathrooms, laundry rooms and basements. Houses over 25 years old are the most likely candidates for water hammer, as the only method used to manage water pressure when these homes were built was to install vertical pipe risers along horizontal pipe runs at 24-inch intervals. Over a long period of time, these vertical pipes can fill with water, creating an ideal breeding ground for bacteria that may end up contaminating your home's drinkable water. 3 types of water hammer arrestors most commonly used in residential water pipe systems are explained in detail below.

Single Chamber Water Hammer Arrestor

Most often used on 1/2-inch pipe systems, the single chamber water hammer arrestor can be installed easily into any section of pipe where it is needed. Its sealed air chamber absorbs the energy from water pipe pressure surges, staying dry and moisture-free. Made of copper, these arrestors suit water temperatures up to 180 degrees F. (82 C.). These water hammer arrestors are also available for 3/4-inch and 1-inch water pipes, and can be installed at any angle to the main pipe. If a threaded join is not available to attach the single chamber water hammer arrestor, it can be soldered into place on a T-joint, fitted into the existing water pipe, taking up little space behind the wall panel.

Mini End Stop Water Hammer Arrestor

This type of water hammer arrestor comes with a 90-degree angled fitting and a threaded end to be directly attached to the hose connection of a washing machine, dishwasher or other water-using appliance. It can also be used on 1/2-inch, 3/4-inch and 1-inch diameter water pipes. They can be screwed to a threaded fitting or soldered directly into the pipe itself. While these water hammer arrestors work best when installed at 90 degrees to the main pipe, their watertight inner chambers will eliminate water hammer at any angle. They take up minimal space behind any interior wall.

Hose Bib Style Water Hammer Arrestor

This style of water hammer arrestor has a 6-inch wide PVC housing with an internal diaphragm to disperse the shock of water flowing through a quick-closing valve. These are ideally suited to be attached directly to the water intake on a washing machine as they can handle high water volumes and higher water pressures than the other models. They are not suited for installation inside a wall due to their large diameter.

Cost of a Water Hammer Arrestor

Single chamber water hammer arrestors are priced as low as $15.00. The hose-bib style of water hammer arrestor can cost up to $125.00, with installation fees extra. You can purchase water hammer arrestors and their accessories at any building supply, hardware or plumbing specialty store. Buy 1 water hammer arrestor for every 20 feet of horizontal water pipe in your home.