Hi,

I want to run a air line underground from my compressor in my garage to my shed.

Can I use PVC pipe or do I have to use metal. The compressor has a max of 150 psi.

I'd rather use the PVC as it's cut, glue and go!!

What do you guy think??

Anthony

Hi,

I want to run a air line underground from my compressor in my garage to my shed.

Can I use PVC pipe or do I have to use metal. The compressor has a max of 150 psi.

I'd rather use the PVC as it's cut, glue and go!!

What do you guy think??

Anthony

I don't think PVC will handle the pressure. Maybe sched 40 could. But personally I wouldn't trust pvc with that much pressure. You could call your local "Home Improvement" store and see how much pressure sched 40 can handle. There might also be a stronger pvc available.

i would use copper.
it can be bought on a roll and no joints.
type K, i believe, is what you need.
david

I think schedule 40 pvc can handle the pressure but personally I would use type L ridgid copper, for two reasons. It can handle more then enough pressure, and since you will be running it under ground the cool earth will help to condense the vapor in the line so it can be removed with a seperator. Kind of like a free refrigerated air line drier.

pvc should be fine...it'll hold up to 400 psi..plenty.i would guard it with a piece of treated wood so as not to hit it later with a shovel. but earth will ont effect it.
also it may sweat/condense less than steel/metalic pipes because plastic does not transmit temps as well/insulating quality.
my whole shop is 1" pvc. and the only thing ya gfott a be aware of is in the winter its more brittle.
just my humble opinion but the pvc werked fine for me

PVC may seem like the easy way to go but it is NOT rated for use with compressed air and is unsafe, period. The problem is that it is not ductile - if a metal pipe gets a crack or is hit by something it will simply bend or deform. If this happend to PVC, it will catastrophically fail and send shrapnel all over the place. It can injure or kill.

None of the PVC pipe manufacturers will certify their product for air. OSHA also says no, and if they find it in a commercial shop they will issue a citation.

There is one brand of ABS plastic pipe that I know of that is rated for use with compressed air, but it's expensive and you're not going to find it at Home Depot.

Here's a link to a good discussion of the issue, click on the link and go partway down the page.
http://www.ford-trucks.com/forums/sh...ad.php?t=99689

Regardless of what anyone tells you about how they've used it and it worked fine, DON'T DO IT. If you're not worried about your own safety, think about your family.

I'm sorry, but this is one of my hot buttons. As an engineer I've worked with compressed air for decades, and I've personally seen the aftermath of exploding PVC air systems more than once. It ain't pretty.

Here's another question on this topic. In using copper pipe. What size do folks recommend? I have used 1/2" in the past and it seemed to work ok. I am going to install a new system. Should I go bigger? Smaller? Most hose is 1/2" or less so I always figured 1/2 would be sufficient.

http://kurtsplates.homestead.com/files/mtn_goat.jpg

If you have a long run and will be using a lot of air, like a sander or sandblaster, for example, use the larger pipe for the long runs to minimize pressure loss.

George

Why not use 1/2" galanized pipe. You can find it at any hardware store. Different fittings and elbows make for easy connections. Just use teflon tape at joints no sweating needed like copper pipe.Besides copper may fail after while because of corrosion or high pressures.

OOps. Should read galvanized.

I have used 1/2" black metal pipe. You can buy it in different sizes and then have the threads cut. And there are many different styles of bends for it. Plus its cheep.

Wow...Thanks for all of your responces.

After reading them all..I have to say that the galvanized pipe sounds like a good idea. I didn't think of that. Being an electrician I can bend that pipe with ease.

Did not know that the PVC is so dangerous. The Gal. pipe will be almost as easy as the PVC.

Gal. it is...Thanks,
Anthony

P.S.---My car has been put on the back burner until I get the yard in shape for the summer. I'll get back to it next weekend I hope.

My personal opinion is to use galvanized if you are going underground, no corrosion issues like there will be with black pipe. If you decide on PVC go to schedual 80. Like GK said in his post I would go to a bigger diameter pipe 1" would be plenty, you can reduce down with a bell reducer to 1/2" for connections. Any extra cost will be offset by better pressure. Be sure to teflon tape all threads good.

Ever try to bend 1" Gal. http://forums.performanceyears.com/g...s/icon_eek.gif

3/4" will have to be good....only about 40' anyway.

While fixing the underground sprinklers. I'd thought I put the line in. I may use it 10 times a year and I may not at all. But it will be there.

Anthony

I used 1/2" schedule 40 pvc in my garage and it works great. It is rated up to 600psi, which is more than enough for a 150psi compressor.

I haven't had any problems running impact guns or DA sanders with this setup.

I vote copper. Sweating pipes is easy, cheap, and fun. I like the maleability of copper - it will deform upon failure rather than shrapnel.

A couple of thoughts on the buried PVC. Where do you live? If you live in a cold climate ground frost heave will quickly crack brittle cold pressurized PVC. Also if any condensation remains in the line at a low spot, freezing in winter the PVC will split.

Er ah, garden hose comes to my mind.
The hose that stays mostly round, and having cross-braid.

Brass fittings with rubber washers rather than plastic joints and plastic washers.

Public water presure is 90PSI, so the garden hose handles more than that. Swell huh.

HIS

LOL Anthony, that 1" galvanized pipe was a little tougher than that conduit youre used to ehhh. http://forums.performanceyears.com/g.../icon_razz.gif I hafta ride with squid on this one, mainly cuz copper will never corrode underground and youll probably have no connections underground. And I certainly wouldnt use PVC, especially in a cold climate. Its far too vulnerable to damage, even in a warm climate.