Plumbing Zone - Professional Plumbers Forum banner
1 - 20 of 29 Posts

·
Retired Moderator
Joined
·
6,781 Posts
Discussion Starter · #1 ·
I noticed a lot of people use a section of pipe above the washer box as a hammer arrestor. Is this better than using the factory ones you can buy?
 

·
Registered
Joined
·
425 Posts
Our inspectors in my area won't accept the air chambers.They want to see mechanical hammer arrestors.A few hundred miles north of here they're putting them on everything from what I here.
 

·
Master Plumber
Joined
·
1,069 Posts
I want to do a test. I need clear tubing of some sort. maybe the clear PEX?

I am going to install air chambers on my tub and watch to see how long until the air is absorbed.

Anyone have any ideas on how I should do the test?

1/2" or 3/4"

I assume 12" air chambers. Right?

Shall I use clear PEX? It isn't really clear but you could see the water level I think.

Anyone interested in the results?
 

·
Retired Moderator
Joined
·
6,781 Posts
Discussion Starter · #5 ·
I want to do a test. I need clear tubing of some sort. maybe the clear PEX?

I am going to install air chambers on my tub and watch to see how long until the air is absorbed.

Anyone have any ideas on how I should do the test?

1/2" or 3/4"

I assume 12" air chambers. Right?

Shall I use clear PEX? It isn't really clear but you could see the water level I think.

Anyone interested in the results?
Umm, did someone wake up on the wrong side of the bed:whistling2:
 

·
Banned
Joined
·
3,806 Posts
I want to do a test. I need clear tubing of some sort. maybe the clear PEX?

I am going to install air chambers on my tub and watch to see how long until the air is absorbed.

Anyone have any ideas on how I should do the test?

1/2" or 3/4"

I assume 12" air chambers. Right?

Shall I use clear PEX? It isn't really clear but you could see the water level I think.

Anyone interested in the results?
Water hammer would not be all that noticeable, if at all, using plastic pipe.
 

·
Ridgid tool user
Joined
·
4,909 Posts
I think this is not to test the idea of water hammer but the theory that water absorbes the oxygen making the arrestor water logged and useless. I know that happens but I'm curious to see how fast this happens. I've always been taught that arrestors are to be 18" btw.
 

·
Banned
Joined
·
3,806 Posts
Huh? I didn't mean anything negative against you. Or anyone. I just keep claiming they are a waste of time and money and few people believe me.
Using the piping systems you install for water pipe, they are.

Using the material I use to pipe a condo, they are not.
 

·
Master Plumber
Joined
·
1,069 Posts
Water hammer would not be all that noticeable, if at all, using plastic pipe.
It's not to test water hammer, but the rate the water absorbs the air cushion.

The rest of my system is iron pipe and copper. The only thing that would be PEX is the air chamber.

Do you have any better ideas for the pipe I would be using?
 

·
Master Plumber
Joined
·
1,069 Posts
Using the piping systems you install for water pipe, they are.

Using the material I use to pipe a condo, they are not.
BTW, what would constitute a waste of time and materials in your opinion?

Can we agree on a standard here? If the air cushion is absorbed in 90 days? Would you consider that a failure of the intended purpose of the air chamber?
 

·
Banned
Joined
·
3,806 Posts
BTW, what would constitute a waste of time and materials in your opinion?

Can we agree on a standard here? If the air cushion is absorbed in 90 days? Would you consider that a failure of the intended purpose of the air chamber?
My point is this, using PEX is not going to prove your point, because the loss of the cushion is going to be affected by the give in the water line itself, you are not conducting a sound scientific test.
 

·
Master Plumber
Joined
·
1,069 Posts
My point is this, using PEX is not going to prove your point, because the loss of the cushion is going to be affected by the give in the water line itself, you are not conducting a sound scientific test.
OK, do you have an alternative suggestion that would be transparent and meet your criteria?

BTW, 1/2" or 3/4", 12" or 18"?
 

·
Banned
Joined
·
3,806 Posts
OK, do you have an alternative suggestion that would be transparent and meet your criteria?

BTW, 1/2" or 3/4", 12" or 18"?
You can get clear sch 80 threaded plastic pipe, the price is outrageous though.

12" air chamber at every opening, and a 24" air chamber on the top of every riser.
 

·
Master Plumber
Joined
·
1,069 Posts
You can get clear sch 80 threaded plastic pipe, the price is outrageous though.

12" air chamber at every opening, and a 24" air chamber on the top of every riser.
OK, so are you saying that if I put a 12" air chamber on the hot and cold of my tub, you would not consider the results to be valid unless the rest of the fixtures each had one too?

Just making sure I understand you here.

Also, would you consider them to be a failure if they filled with water in 90 days?
 

·
Master Plumber
Joined
·
1,069 Posts
I believe residential air chambers are useless on metal pipes. They fill up over time.
There are a lot of very intelligent plumbers who disagree with you on this.

Then there are also those who do agree but just say, well, drain the water lines periodically.

I am trying to figure out under what conditions they would accept evidence of a failure.
 

·
Banned
Joined
·
3,806 Posts
OK, so are you saying that if I put a 12" air chamber on the hot and cold of my tub, you would not consider the results to be valid unless the rest of the fixtures each had one too?

Just making sure I understand you here.

Also, would you consider them to be a failure if they filled with water in 90 days?
If you are cherry picking where to use them and where not you are setting them up to fail now aren't you?
 

·
every tool is a hammer
Joined
·
4,304 Posts
One of my apprentice instructors told us that some organisation plumbed a module house with glass pipe, for testing purposes. The air chambers filled up in about 6 months. Bullshit? Maybe. I will do a google search and see what comes up. I do know that when I remodel and cut out copper for scrap, the airchambers always have water in them. It is pulling a vacuum and doesn't come out until I am cutting the solder joints out, so maybe there is a small pocket of air left.
 
1 - 20 of 29 Posts
Top