plumbing 4 air ?

[CurlyDave]

I don't want to be digging fragments of PVC or copper out of my body should they rupture under 120psi.

Another thing to consider about PVC.

Plastic and wooden bullets are outlawed by the Geneva convention for a number of reasons, one being that plastic and wood do not show up well on X-rays.

I would hate to be full of PVC shrapnel that the medics just can't find...

[Diamondpilot]

I used pex and it works fine. I have a compressor in a pole barn and put quite a few work ports around the shop. I even dug a trench to the house and ran it into the attached garage, a first floor closet, and a second floor closet. Very handy and with pex there are very few fittings.

Chris

[john_bud]

I used PVC in the shop air supply for about 12 years. The compressor is in the non-heated part of the shop and the lines go thru the wall up high and distribute around. Was in the shop last winter (-20F or so outside) and while using the needle scaler there was a H*ll of an explosion behind me. I was wearing protective eye wear and hearing protection, but even so it was loud! Jumped up and spun around to see a huge cloud of vapor and a large hisssss.

Yep, the cold contracted the PVC and then when the air cycled up and down it expanded it and contracted it more. Guess it fatigued, don't know for sure. Do know for sure that a Y and a T and a 3' section blew apart and put PVC daggers everywhere. I'm still finding chunks and slivers. Next day went and bought a bunch of black iron pipe. The PVC is cheaper, easier and all that, but....when it lets go - you don't want to be there. Trust me on this one!

Oh, check the price of copper. You don't want to blow that kind of money !

jb

[plaindave]

I had planned on using black iron when I hit upon the idea of using air hoses. I wanted to use PEX but it was too expensive. Air hoses are rated for the pressure and easy to route.

No doubt I'm taking a chance that somehow a line could become compromised, but it't got to be safer than dragging them back and forth across the garage floors and stepping on them for the last 15 years.

1/2" rubber hose is pretty reasonable at Northern Tool and has worked for me for about 4 years now.

[AndyMA]

Originally Posted by Diamondpilot

I used pex and it works fine. I have a compressor in a pole barn and put quite a few work ports around the shop. I even dug a trench to the house and ran it into the attached garage, a first floor closet, and a second floor closet. Very handy and with pex there are very few fittings.

Chris

Plastic pipe comes in many types. Crosslinked, UV stable etc are a few of the characteristics that you might want to look for in a compressed air system. I have attached a spec sheet for Duratec a type of plastic pipe that is designed for compressed gasses.

Andy

[ray66v]

I have experience with this. You will have problems with using PVC for air lines.
I suggest you do not use it.
That being said, If you are going to use it anyway, I suggest the following recommendations: Use a rubber hose from the compressor to the line to limit vibration. A piece of hydraulic hose will work great. Then, use schedule 80 for at least the first connectors. Run your pipe, then change to black pipe at least 3 feet before you want to put your air hose. And make sure the black pipe is well attached to the wall. This will eliminate the common failure points.
As always slope the pipe toward the drain(s) for condensation. they should be at each drop, (point where you attach the hose). Drop meaning run the hose high enough on the wall that you can have a vertical pipe dropping down for the hose, put a tee in the drop for the hose and continue down about 2' more and put a drain at the bottom. All this must be in black pipe. It also helps with condensation to run one more drop past the last one you plan to use. This is because the end drop gets the most water.

[patrick_g]

Yet more comments on PEX. Not all PEX is created equal. There are different manufacturing processes for cross linking and different UV stabilizations. NEVER buy PEX from a supplier that stores his bulk PEX outside. UV stabilization mostly reduces degradation, not eliminate it.

PEX can be severely weakened and sometimes embrittled by exposure to sunlight (especially UV.) I am not anti-PEX and I plumbed my current house with it as well as the hydronics (in-floor, in-ceiling, and some in-wall) but I wouldn't use it where it would be exposed to UV such as is in natural light. The weakening is cumulative over time depending on intensity of exposure and duration. PEX might work well for a long time but when will it rupture due to the long term effects of light if it is exposed?

I was planning on going with the traditional iron pipe and rely on a simple filters to handle any rust but after I finish reading the nice PDF file referenced in a previous post I might go with that plastic if price, availability and performance warrant it.

Lots of good reasons listed for NOT using PVC in this thread, I have excerpted them printed out the list of the most dire warnings to give in paper form to my friend whoi had his shop plumbed with PVC. Short of a commando raid to remove his PVC and install iron when he isn't looking, there isn't much more I can do.

Pat

[firemanpat2910]

wow, we have never had a problem, but I will see about replacing the pvc. At least any thats not in the walls. I dont think we will be ripping the sheetrock out anytime soon.

[john_bud]

Originally Posted by firemanpat2910

wow, we have never had a problem, but I will see about replacing the pvc. At least any thats not in the walls. I dont think we will be ripping the sheetrock out anytime soon.

If it fails, you'll have the rock removed for you. How handy is that?

jb

[patrick_g]

I was wondering if anyone else tried to get info on the plastic pipe for compressed air. I downloaded their price sheets and other info in PDF but when I called them to find out where there was a distributor I got deeply enmeshed in their automated telephone system and never got a live person or the info I wanted. On one attempt I was able to leave a message but got no response. I hate it when you have to expend so much effort to try to get info on how to buy something. You'd think they would be interested in either selling it to you or telling you where you can get it.

Pat