# Testing new plumbing with air pressure



## Grampa Bud (Apr 6, 2009)

No unfortunately your test is not over kill. In fact here in the chicago area some counties and/or villages require a mandatory 100 P.S.I. for 24 hours test of the potable water supply for all new or altered installations. This does not mean just what you are working on. It means the whole system in your home. Something is leaking and it must be found and fixed. 30 P.S.I. over 24 hours is a pretty good leak. We've had as little as a 4# leak in 24 hours and the inspector won't sign off on it.
Look at your gauge threads and the shrader valve also. In fact put a heavy soap solution (almost a paste) on all the threaded connections and pump it up to 100 P.S.I. and slowly and quietly check everything. A lot of times you will actually hear a 1mm bubble pop before you ever see it. Good Luck.


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## Niffumdutz (Jan 11, 2010)

Ok, thanks for your response. I'd be happy to fix it, I just can't find it!


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## Gladerunner (Mar 9, 2010)

why not test with water? put a boiler drain (hose bibb) on one of your lines and fill.


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## COLDIRON (Mar 15, 2009)

You really should check it with water pressure its safer and more predicable.
Fill it up and make sure all valves are shut off when you start the test.
People have used air and it got away from them and blew up water don't blow up it just leaks all over.


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## tpolk (Nov 7, 2009)

are your fixtures connected? or just rough in


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## Niffumdutz (Jan 11, 2010)

tpolk said:


> are your fixtures connected? or just rough in


They're just roughed in. I'm using the Delta dummy plates, which are a pretty sweet deal that I haven't seen before.
I put the pressure up to 100 lbs, and soaped _again_ and found one tiny (!) little leak at the threads to the manifold. Went thru the fix it drill again, and put 100 lbs back on it. 
We'll see what the pressure is in the morning. I know it easier finding leaks with actual water, and I would have done it that way, but it's easier doing all the rest of the plumbing later on.

Thanks for the input, guys.


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## tpolk (Nov 7, 2009)

wondered if you might be losing air thru the fixture


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## Niffumdutz (Jan 11, 2010)

Well, that was my first thought too. So I soaped the living daylights out of it, and no bubbles there.


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## fireguy (May 3, 2007)

What PSI is required for the pressure test? The working pressure for water pipe and fittings is 175 PSI. Water is the best chemical to use, cheapest and safest. Do not use air on plastic! PVC and CPVC will shatter when it breaks.


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## Gladerunner (Mar 9, 2010)

standard plumbing piping and fittings are rated for 125#.


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## Alan (Apr 12, 2006)

Usually our 'leaks' end up being the little needle in the valve stem we used to charge the lines.

Occasionally when testing with air, the leak will occur in a shower valve (air pushing past o-rings) and coming out of the shower head nipple. Capping showerhead will solve that issue.


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## Niffumdutz (Jan 11, 2010)

Alan said:


> Usually our 'leaks' end up being the little needle in the valve stem we used to charge the lines.
> 
> Occasionally when testing with air, the leak will occur in a shower valve (air pushing past o-rings) and coming out of the shower head nipple. Capping showerhead will solve that issue.


Thanks. That seems to be what's going on here. I don't have these kind of "leaks" when I hook up live plumbing.......maybe one or two.


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## livingdead (Jun 18, 2011)

Hey niffumdutz, could you be more specific on that threaded tire valve connection to your plumbing, I have a raised slab to pour with pex tubing and need to check for leaks before the pour, I was thinking that maybe if I could find a way to connect a tire valve to the pex tubing, I could pressurize the tubes and check for leaks. but I don't know where or what exactly to ask for to convert and adapt to 3/4" pex.


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## Grampa Bud (Apr 6, 2009)

Livingdead : Are you puting down 3/4" pex in the slab for potable water or are you installing radiant heat?


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## TheEplumber (Jul 20, 2010)

I have had success on hard to find leaks by reducing pressure to 20 or so lbs. 
my theory is that high pressure blows the soap away before it has a chance to bubble.


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## biggles (Jan 1, 2008)

did you cap :wink: the shradder after the pressure was installed


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## livingdead (Jun 18, 2011)

*radiant heat*



Grampa Bud said:


> Livingdead : Are you puting down 3/4" pex in the slab for potable water or are you installing radiant heat?


It's for radiant heat.


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## Grampa Bud (Apr 6, 2009)

Livingdead : Build your loop headers first, then hook up your pex from the floor to the headers; one feed and one return; then waste a couple of bucks and solder a cap on both ends of the return header with 6" X 3/4" stubs between the header and caps. On the feed solder a 6"X3/4" stub and cap on one end of the header and a 6" X 3/4" stub and a 3/4 sweat X 1/2" threaded reducer on the other end. Then you can build a "test tree" from common plumbing parts with a 1/4" pressure guage, a 1/2" teflon ball valve, and a male 1/4" male Milton hose fitting. The same as you would use on your air compressor. You will need a couple small nipples, maybe a brass reducer or two in the right sizes, and some teflon tape and you won't have to screw with bicycle tube valves or shrader valves and get on with the project. Good Luck.


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## Alan (Apr 12, 2006)

livingdead said:


> Hey niffumdutz, could you be more specific on that threaded tire valve connection to your plumbing, I have a raised slab to pour with pex tubing and need to check for leaks before the pour, I was thinking that maybe if I could find a way to connect a tire valve to the pex tubing, I could pressurize the tubes and check for leaks. but I don't know where or what exactly to ask for to convert and adapt to 3/4" pex.


This thread is over a year old and has been solved. . . . . :no:


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## Grampa Bud (Apr 6, 2009)

Alan : If it is a year old then I apologize, but DIY Chat or someone has been peppering me with this thread over the last few days. I was interested in livingdead's reply/question because it sounded like a radiant problem and I did designing, building, and repair on radiant systems for 15 years. Plus he responded to my reply to him. If nothing else and if you have any pull with DIY Chat maybe a date-time stamp could be added to replies to threads or if threads are solved/completed they could be removed from the data base.


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## Ishmael (Apr 24, 2007)

Grampa Bud said:


> In fact here in the chicago area some counties and/or villages require a mandatory 100 P.S.I. for 24 hours




24 hours?!?! Here in MA, it's 125psi for 15 minutes.


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## livingdead (Jun 18, 2011)

:thumbup: It's for radiant heat but I figured it out, and tested it, looks pretty good.


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