Necessity of a water hammer arrestor?

Daox · 08-27-12, 02:23 PM

I replaced the kitchen faucet at my grandmothers last night. The new faucet must turn the water on/off faster, or have a higher flow rate than the last one because the water hammer effect is fairly bad. It moves the copper pipes in the basement around 1/2". I know this isn't good an the pipes will eventually fatigue and spring a leak somewhere. I'm thinking the best way to fix this is to add a water hammer arrestor? I know what they are and what they do, but I've never put one in or if there are other options.

Xringer · 08-27-12, 03:47 PM

LOL! Tell her to turn off the water very slowly..

I've used water hammer suppressors that looked like small versions of expansion tanks.
0269503 - Watts 0269503 - 150A, 1/2" Water Hammer Arrestor

Sadly, they only lasted a few years before the rubber disc wore out and leaked.
Can't really recommend them.

I went with a DIY air-pocket unit using 3/4" pipe. But, I placed the pipe very near where the water comes into the house.

Kinda like this..

I've used short air-pockets before and sometimes they fill up with water (to the top).
So, my 3/4" air pocket is about 6 feet tall.. It's never filled up yet..

If you decide to add some, I think at the end of a long run without bends is the best place.
(Mine is at the end of the long 3/4" run from the street).

If you can use a gentle turn, instead of a sharp 90deg turn into the air pocket, it will work better.
Like using a couple of 45deg elbows, instead of one 90deg elbow.

hamsterpower · 08-27-12, 07:01 PM

+1 for the Xringer's suggestion.

Also where the pipes are moving add more brackets to secure the pipe. Straps or brackets every couple feet.

08-27-12, 02:23 PM	#1
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Necessity of a water hammer arrestor? I replaced the kitchen faucet at my grandmothers last night. The new faucet must turn the water on/off faster, or have a higher flow rate than the last one because the water hammer effect is fairly bad. It moves the copper pipes in the basement around 1/2". I know this isn't good an the pipes will eventually fatigue and spring a leak somewhere. I'm thinking the best way to fix this is to add a water hammer arrestor? I know what they are and what they do, but I've never put one in or if there are other options. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-27-12, 03:47 PM	#2
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	LOL! Tell her to turn off the water very slowly.. I've used water hammer suppressors that looked like small versions of expansion tanks. 0269503 - Watts 0269503 - 150A, 1/2" Water Hammer Arrestor Sadly, they only lasted a few years before the rubber disc wore out and leaked. Can't really recommend them. I went with a DIY air-pocket unit using 3/4" pipe. But, I placed the pipe very near where the water comes into the house. Kinda like this.. I've used short air-pockets before and sometimes they fill up with water (to the top). So, my 3/4" air pocket is about 6 feet tall.. It's never filled up yet.. If you decide to add some, I think at the end of a long run without bends is the best place. (Mine is at the end of the long 3/4" run from the street). If you can use a gentle turn, instead of a sharp 90deg turn into the air pocket, it will work better. Like using a couple of 45deg elbows, instead of one 90deg elbow. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

08-27-12, 07:01 PM	#3
hamsterpower Apprentice EcoRenovator Join Date: Oct 2009 Posts: 142 Thanks: 0 Thanked 11 Times in 11 Posts	+1 for the Xringer's suggestion. Also where the pipes are moving add more brackets to secure the pipe. Straps or brackets every couple feet.