# pressure testing copper pipe



## COLDIRON (Mar 15, 2009)

You can if you just turn the water on and look for leaks.

Using air can be dangerous water lines should be hydrostatic tested with water pressure.
The reason is if the line bursts with air pressure it could send shrapnel all over the place. if the pipe bursts with water pressure it just leaks.

In addition you could have a faulty air compressor regulator that is unreliable and over pressurizing the line causing it to burst.


----------



## Ishmael (Apr 24, 2007)

john_bry said:


> Can i pressure test the copper pipe plumbing rough in with the gas water heater in the circuit? I was gonna test with air at 40 psi?


Of course you can. Here in MA, our code requires we test the water supply piping _"...under a pressure of not less than *125psi*"._ We typically perform that test with compressed air.

Now...about the water heater: A big part of my business is winterizing summer vacation homes so nothing freezes while the house sits empty for months on end. I often will blow the lines out with an air compressor rather than a gravity draining to the low points. The water heater usually does not have an isolation valve on the hot water side which means I have to pressurize the entire tank. I pump them right up to 125psi with no problems. The T&P relief valve is usually set to "blow" at about 150psi, so that's not a concern. Test pressure is defined as 150% of working pressure. Working pressure is (often) up to 80psi, so the test pressure should be 120psi.

But it does take a little while for the compressor to pressurize an empty hot water tank.


----------



## COLDIRON (Mar 15, 2009)

Just use the water pressure that is supplied to the property, THIS IS A RECORDING DO NOT USE AIR.

It's not needed and it is dangerous.


----------



## tylernt (Jul 5, 2012)

I wouldn't ever put _any _kind of air pressure on a system with PVC/CPVC in it, when they shatter they can send out sharp shards at high speed that could really do a number on somebody. 

But people use copper to plumb compressed air into their shops to run air tools all the time, so air testing a pure copper water plumbing system (or iron, for that matter) doesn't _seem _to be a totally insane idea.


----------



## paintdrying (Jul 13, 2012)

Leak is a lot easier to sweat with air as opposed to water.


----------



## COLDIRON (Mar 15, 2009)

paintdrying said:


> Leak is a lot easier to sweat with air as opposed to water.


"I never sweat with air or water, I use silver solder ,Stick, stay brite.

The point is safety that's the reason Hydrostatic testing is used not whether a job is easier or not.
Just buy a hand grenade hold it in your hand and pull the pin, don't throw it just hold it see what happens.
That's what could happen it the system over pressurizes. Never say never things happen.
Suppose your pressurizing a system and the gauge and regulator is faulty, BOOM.
Suppose your filling a system with air and someone takes your attention away (ever have that happen)?) BOOM. Not likely but it only takes one time. I've used air, freon, nitro, water, etc, etc many times but I am not telling you or any one else to do it. It all depends upon size, specifications, and the type of job and many other things I am sure. Use what you want to leak check your going to any way. Just picture testing Oxygen tanks, Nitrogen tanks, Hydraulic tanks, Boilers with air at a couple thousand pounds . Air or water?


----------



## tylernt (Jul 5, 2012)

COLDIRON said:


> That's what could happen it the system over pressurizes.


You know copper is rated for compressed air at working pressures far in excess of what a portable air compressor can achieve?

http://www.copper.org/applications/plumbing/techref/cth/cth_2select_recom.html

http://www.copper.org/applications/plumbing/techref/cth/tables/cth_table3c.html

http://www.copper.org/applications/plumbing/techref/cth/cth_3design_burst.html

http://www.copper.org/applications/plumbing/techref/cth/tables/cth_table5.html

The actual burst pressure of 1" type M copper water piping is 3,865 PSI (smaller pipes hold even higher pressure). If you've got an air compressor that goes that high, don't use it for testing water pipes!!



> Never say never things happen.


Well, I guess we'd better install steel plate on the roof of all human-habitable structures in case a meteor falls. Hey, best to err on the side of caution.


----------



## Ishmael (Apr 24, 2007)

tylernt said:


> You know copper is rated for compressed air at working pressures far in excess of what a portable air compressor can achieve?
> 
> http://www.copper.org/applications/plumbing/techref/cth/cth_2select_recom.html
> 
> ...


What if my little Em-glo portable compressor malfunctions and generates over 2 tons per square inch? :laughing:


----------



## TheEplumber (Jul 20, 2010)

I always use air for testing copper and pex. And I always watch the gauge too. I test to 1.5 times working pressure.
I have also been injured by a system charged with air- unsweating a 1/2" cap and I assumed the test was of. Luckily I wear glasses because the solder hit my face like a shotgun blast. The cap hit my heavy coat. Scared me and damaged my pride :laughing: Had it been hydro tested, I wouldn't have been able to heat the cap to the point of it blowing off.
Another time a friend wasn't so lucky. He still has metal frags in his arm from a failed vic coupling. Yes, air is dangerous. Every failed air test I have know of has been due to installer error or bad fittings


----------



## hvac benny (Dec 29, 2009)

Better stick to a bicycle pump.


----------

