Water hammer, also known as hydraulic shock, is a concussion sound that occurs when water moves against the sides of a pipe or container. It is caused by a rapid deceleration of water flow in an enclosed space. To solve this problem, you can use a water hammer suppressor or an air chamber. An air chamber is an extension of the water supply pipe near the pipe fitting that provides an air cushion to absorb hydraulic shock. To recharge the air chambers in a plumbing system, start by turning off the water in the water meter.
Then open the tallest faucets first (the ones that are farthest from the meter) and then go down to the basement or utility room. When you turn on the laundry faucet, usually the lowest in the house, the whole house drains into the bathtub. Don't forget to open the keys to the outer sill and pull the toilet chain on your way. To fill the chambers with air, you need to completely drain the water from your plumbing system. As the pipes drain, so does the water in the air chambers.
The first step is to close the main water supply valve. Then turn on all the faucets in the house and flush all the toilets. Turn on the lowest faucet (s) (hot and cold) in the house, or a drainage system, if you have one, and all the water will flow out of the pipes. Don't forget to turn on the washing machine (turn it hot to open the hot and cold valves) and the dishwasher for a few moments to make sure the pipes are also completely drained. If you have a water hammer problem, you can cure it by turning off the water behind the flooded chamber, opening the offending tap, and allowing it to drain completely.
Once all of the water is drained from the chamber, air will refill it and restore its cushion. To do this, you will need to remove any plumbing fixtures where water hammer is taking place. Trim drywall around water supply valves to access wall pipes. Loosen up any couplers with an adjustable wrench and slide out any valves, ferrule, and couplers from copper tubing. Cut an 18-inch copper pipe that matches with diameter of copper pipe from wall with a pipe cutter.
Clean up any burrs on each end of pipe and apply flux to one end of copper pipe and inside of copper cap of same diameter as pipe. Weld cap to pipe with welding wire and torch. Spread some pipe glue around one end of 1-foot pipe section and slide tube cap over end of tube. Spread some more glue around other end of pipe and inside male end of reducer. Insert tube into reducer and wait for about half an hour for glue to dry inside pipe. The air chamber is now complete! Turn off faucet and open shut-off valve to refill line with water.
It will be sprayed to remove excess air but will trap air in chamber. The hammer should no longer be produced; you will need to do this for both cold and heat supply lines. An air chamber is a device used to absorb pressure increase when flow of water suddenly stops. It has fittings that screw onto a faucet, toilet, or appliance hose, and an air chamber made with a diaphragm or piston in a sealed chamber.
