Do I need a hammer arrestor?

Could you guys please comment on whether or not you recommend that I attach a hammer arrestor to this system?

Facing you is 1/2" to a lav and going away is 1/2" to a laundry sink.

I could solder a T and 6" vertical with a cap on the hot and cold of each side, if you think it is necessary.

Thanks for opinions.

You don't need arrestors for a lav or laundry sink.

You would for a washer, icemaker and dishwasher

A friend of mine used to get woken in the middle of the night everytime his fridge refilled the ice trays.
Then he installed a hammer arrestor and was able to sleep.

thank you

Thanks for the hellp, Terry.

I have seen quarter turn lavatory faucets which closed so quickly they did create a water hammer. But, air chambers are only a temporary solution, and a 6" one would be useless.

Hj question

Hj,

what would you suggest in this lav case?

If you want to add an arrestor, use an engineered one that will last a very long time. Several companies make them, but here is one manufacutrer's take on them http://www.siouxchief.com/Supply/Arresters-And-Trap-Primers/Water-Hammer-Arresters2 To work best, they need to be closest to the offending valve. As noted, many valves don't close fast enough to create the problem (electric valves as used in WM, ice makers, ect. as said previously are more normal culprits), but if you have one, this is the preferred solution. As you can see, you have a choice on how to attach one in. You could put in a threaded fitting and just put a plug in it until you found out if you needed one. Or put in a T and cap it and add one later (assuming you have access. Since these do eventually fail (likely many years down the road, you'd want to have ready access.

thanks for the input, jadnashua.

In this area, which can have a vast range of water pressures, I have NEVER installed any provision for preventing water hammer, and have never seen anyone else who did it either. Therefore, my initial reaction to your question would be "don't do anything". I guess one question would be "why did you 'waste' so much tubing by putting the tees that high and then dropping down to the desired location, rather than putting the tees where the other ones are and just arming over to there?"

Thanks hj!

Thanks again for the replies.