Testing Plumbing without water

[chad215]

I've got a little shop that I've been working on building and I've framed out a small bedroom and bathroom. I'm darn near at drywall stage for the bedroom.
I've run PEX A for a future shop sink but a lot of the line goes through my bedroom ceiling and walls. I'm getting ready to attached my copper stub outs to seal up those ends. I have NO WATER available. I plan on doing a rainwater collection system in the future.
I'm really wanting to test these lines before I finish all the insulation and drywall. Is there a way to do this with air?
I guess I could tote in some five gallon buckets and a water pump if I really needed to...

Any suggestions on ways to check for leaks?

 

[Walkers]

You can test with air, but with air bubbling out the pressure lost doesn’t show up very fast. When water drips out the pressure loss shows up immediately, water being non compressible.

 

[duneslider]

THis gets done all the time in my area. I would venture that the majority of homes are pressure tested this way. I know my house was. They pressure test the gas supply lines, domestic water, and waste water drains with compressed air. I would assume there is a youtube video showing this. I usually saw the gauges installed on the shower heads in houses, bathroom sink drains, and I think usually 60psi (ish) not sure if there is a rule on this or not. I know when it is done with air they have to let it sit for a number of hours before inspection can happen.

 

[chad215]

For some reason I didn't even think to google this. Looks like it's pretty common. Thank you both for your replies.

 

[jrsavoie]

I've tested as high as 160 lbs air pressure, depending on what's in the line.

I install a ball valve and pressure gauge. Fill it up and shut the ball valve

 

[mike93lx]

I've tested as high as 160 lbs air pressure, depending on what's in the line.

I install a ball valve and pressure gauge. Fill it up and shut the ball valve

Then wait a while. Not sure what is standard, but I'd give it 24hrs to be sure

 

[chad215]

Then wait a while. Not sure what is standard, but I'd give it 24hrs to be sure

That's my intention. Think soap would help detect leaks at the fittings like you do with tires? I suppose the liquid would evaporate too quickly.

 

[firebirdparts]

Air is good for leak checking, although inferior to water.

I'm actually a pro at this, FWIW. It's routine for certain operations industrially. You can measure pressure loss and you can spray with soap to find leaks. We always make a standard # psi per hour, but you don't have much volume there, so tiny leaks will give you a huge response. If you have the water heater tied in, that'll make the response more muted. Be aware that air might be leaking through valves and act accordingly. Be aware that the day/night and post-compressor air temperature cooling down to ambient all effect the pressure if you are going by that. You're indoors so if you give it a while to cool off it should be pretty easy to get it right.

Air is not really safe for breaking things, but that's not what you're trying to do here. If you break something under air testing, it flies a long way, so it's not popular.

 

[duneslider]

That's my intention. Think soap would help detect leaks at the fittings like you do with tires? I suppose the liquid would evaporate too quickly.

I don't know how many joints you have but this would take forever in a house...

 

[kbs2244]

when I worked as a purchasing guy for an industrural plumbing contractor
I put together 15 air pressure kits for each plumber for their 24 hour pressure tests
a small compressor, a collection of adaptors, 2 ball valves, a Shrader valve, and 2 pressure gauges.
they would cap off the ends and pump them up
supply and drain
it was code required and had to be signed off by the plumber

 

[jrsavoie]

Then wait a while. Not sure what is standard, but I'd give it 24hrs to be sure

Yep. I should have included waiting. I've waited as long as 2 weeks on a pex system. Just because that's when we got back to it.

I also, sometimes plug the threaded ball valve just to eliminate ball valve leakage as a source of pressure drop.

I forget what pressure a forgetting solder joint blows apart - it wasn't much. But more than I thought it would be.

 

[Renegade1LI]

In the trade, we use mega bubble for air testing, find leaks that soapy water doesn't, you'll be glad you got it.

Hercules Megabubble 8 oz. All-Purpose and Gas Leak Detector 45801 - The Home Depot

Hercules Megabubble Leak Detector uses a high-viscosity formula that produces large, long-lastings blue bubbles for easier detection of leaks on pipes, fittings, tanks, coils, cylinders, pressure vessels

www.homedepot.com