What do people like to use to avoid pipe hammer?
New constructuion.
Is it legal to just run a verticle 6 inche pipe at the fixture shut-off valve (trap air to absorb hammer)? Sure, it will fail over time and need to be recharged, not sure what over time is. Sure is a cheap option. Does it work well enough? Do you spring for teh mechanical version at each fixture? Or use them only at dishwashers and washing machines (worst offenders)?
Thougths?
thanks as ususal.
Replies
Excessive incoming water pressure, and, fast closing valves ( washing machine solenoid, dishwasher inlet, icemaker, and ball[JOBSITE WORD]s ), are usually responsible for creating water hammer. Pressure spikes up to 2,000 psi can occur in residential domestic water systems, and, water hammer can also occur in closed loop hydronic piping.
Home made air chambers will become water logged rather quickly, and often, it is not easy to provide a piping strategy that will make the chambers easy to drain for recharging. Water systems that are supplied by a private well, with a properly sized and maintained water storage tank, are less prone to water hammer. These systems usually operate at lower pressures, and the air cushion in the storage tank can absorb some of the effects of water hammer; the tank will also absorb the expansion that occurs while heating hot water.
Municipal water supply systems often operate at dangerously high pressures ( 100 psi & up ). A pressure reducing valve can be installed on the interior water supply piping to regulate incoming water pressure. These devices have a built in check valve, so be aware that expansion from water heating will not be able to escape to the water main; a domestic water expansion tank should be installed near the water heater. Domestic water thermal expansion tanks can also help absorb the shock created by water hammer.
Manufactured water hammer arrestors have a permanent air charge, and work best when located as close as possible to the problem piping or valve, however, they will work when installed several feet away, above or below. They should always be installed in an accessible location. Installing water supply piping with proper supports & spacing, insulation, and isolation from hard edges & tight, drilled holes, can reduce the potential for water hammer; it is not always the best practice to cinch the piping extemely tight.
Thanks for the informative post
Thank you for your thoughtful and lengthy reply!