What are the approved types of water hammer arrestors

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Water Hammer Arresters from FAMOUS PLUMBING SUPPLY

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Originally Posted by reorehaber3

what are the approved types of water hammer arrestors

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There are Water Hammer Arresters and there are Air Chambers. The arresters are mechanical and the air chambers are not, (see the article that Afaroo put up)
Water Hammer Arresters have to be installed outside the wall so they can be serviced while air chambers can be installed inside the walls. We are mandated to install air chamber on the hot and cold raisers of all lavatories and kitchen sinks and, if directed by the contractor, on the washing machine station as well. Is this what you wished to know? Regards, Tom

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Originally Posted by speedball1

There are Water Hammer Arresters and there are Air Chambers. the arresters are mechanical and the air chambers are not, (see the article that Afaroo put up)
Water Hammer Arresters have to be installed outside the wall so they can be serviced while air chambers can be installed inside the walls. We are mandated to install air chamber on the hot and cold raisers of all lavatories and kitchen sinks and, if directed by the contractor, on the washing machine station as well. Is this what you wished to know? regards, Tom

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I am renewing my journeyman's license and the only question that I am stumped on is:

An unacceptable device to eliminate water hammer is?
1. A disphragm type water hammer arrestor
2. A piston type water hammer arrestor
3. An approved flush tank water hammer arrestor
4. An air chamber

I selected #1.