Water Hammer Arresters

Q. "What is water hammer?"
A. Water hammer occurs a lot! It is frequently recognized by a "thump" or "bang", usually throughout the water line (if you have copper pipes, you'll tend to hear the noise throughout the house). Water hammer can be caused by a number of things. Many times a loose washer that is jumping around in the faucet or valve causes it. This can be fixed by identifying which valve is the culprit and fixing the washer. Other times it is simply caused by water traveling at a rapid rate and suddenly being shut off. The best solution for this is to increase the size of the water supply thereby slowing down the water (a larger pipe being able to deliver the same amount of water in gallons per minute at a slower speed). If this is not possible, then many times a water hammer arrester helps. Sometimes the cause is excessive pressure and the best way to deal with that is to install a pressure regulator as well as an expansion tank (needed by many codes once you install a pressure regulator). In any case, please be aware that sometimes water hammer arresters will not solve your water hammer problem.

Q. "What are your most popular hammer arresters?"
A. The 1/2" through 1" (models 652A, 653B and 654C with standard male threads) for most situations, as well as the 660-H which is specifically for hose threads on appliances such as clothes washing machines.

Q. "Can these water hammer arrestors be installed inside a wall?"
A. Yes. All of the water hammer arrestors shown above are approved for sealed wall installations with no access panel required.

Q. "Will water hammer arrestors stop all banging inside my wall? Will it solve my noisy pipes problems?"
A. The water hammer arrestors will not compensate for poor strapping practices. If they are needed and work it is because faucets or valves can be closed too rapidly and create a water hammer. In other words, water hammer arrestors can solve some problems but not all. If you have both bad brakes and bald tires on a car then getting new tires won't solve all of your problems. Same with water hammer arrestors. They can't solve expansion and contraction issues or poor strapping issues but they certainly can usually help somewhat with water hammer issues.

Q. "I see that you have soldered (male sweat) models of water hammer arresters. They seem like a great idea since I won't have to use copper fittings?"
A. Yes, they are a great idea IF you are REAL good at soldering (not overheating). We offer them because we get asked for them. We would like to warn you to not overheat them while soldering as you could then damage the seals. For copper installations, we like to recommend the male threaded type of water arresters (or the compression type if you are using hard copper pipe).

Q. "At what angle can these water hammer arrestors be installed?"
A. Because of their secure water chambers, all Hydra-Restors and Mini-Restors can be installed at any angle.

Q. "We have a high efficiency front loading washing machine. We installed a 660-H on the hot and cold supply lines yet we still have some water hammer noise. How come?"
A. According to the manufacturer one pair of water hammer arresters (Mini-Resters) placed within six feet of the valve should be sufficient to control a pressure rise up to 150 psig maximum and reduce noise caused by uncontrolled water hammer. This should be no different for high effeciency front loading washing machines or common residential washing machines. Most high efficiency front loading washing machines use less water per wash cycle than conventional washing machines. However, their water supply valves turn on and off as many as 16 times per cycle as compared to 3 or 4 times a cycle for conventional machines. This higher supply valve usage may cause a low level, repetitive noise annoying enough to cause the homeowner to assume the Mini-Resters are not working. The pressure surge may be sufficiently controlled by the Mini-Resters and be working as designed yet not eliminate the noise completely. In an effort to further reduce or eliminate this noise, the manufacuter suggests an additional set of Mini-Resters be installed on the supply lines. This means two Mini-Resters installed on each supply hose. With 2 arresters on the cold line and 2 on the hot line, the pressure surge can be further reduced.