Shop Air Lines

[khamill2000]

Anybody ever run PEX for their air lines in the shop. Got about 3 weeks off coming up and am looking to plumb some air lines. I ran steel at the old house but thought with pex I might be able to run it in the walls and keep it real clean looking.

 

[kennyd]

Man, this could get heated
PEX to my knowledge is not rated for air, or exposure to UV light long term...Do some searching on the Web.

I used copper to do mine-it's expensive but the labor is low, and the chance for leaks is a lot less then iron pipe.

 

[khamill2000]

The UV would not be a problem as it would be inside the ceiling/walls

 

[ray66v]

Man, this could get heated

Right, there are many posts on this subject, you can find them by searching. There have been a lot of heated discussions on the use of "other" pipe for compressed air. I have had enough plastic air pipe failures in my life to know what I would want to use, steel pipe. Others will tell you they have never had a problem,... yet.

I seem to remember at one time seeing a special grade of pex that was designed for compressed air.

There is also some sweet aluminum pipe made for compressed air. It uses slip couplings, goes up fast, and looks really nice. It's just expensive.

 

[QRTRHRS]

I agree with copper or black iron. You can also find air line pipe with reusable compression fittings but I would imagine that to be more than copper.

No PEX or PVC for me.

I don't know that I have ever seen air lines run that could not be accessed for maintenance or modification.

 

[QRTRHRS]

Right, there are many posts on this subject, you can find them by searching. There have been a lot of heated discussions on the use of "other" pipe for compressed air. I have had enough plastic air pipe failures in my life to know what I would want to use, steel pipe. Others will tell you they have never had a problem,... yet.

I seem to remember at one time seeing a special grade of pex that was designed for compressed air.

There is also some sweet aluminum pipe made for compressed air. It uses slip couplings, goes up fast, and looks really nice. It's just expensive.

Guess I was typing while you posted. Here is at least one source for the aluminum pipe.

 

[DieselPower]

If your looking to use a flexible air tubing to plumb your shop why not use air brake hose. Get a spool of Synflex DOT rated truck air brake hose and plumb away. It is rated for air, is UV resistant and safe in cold temps. It's what I plumbed the air system on my mobile service truck with.

 

[JB4310]

Don't know what it's called but there is a flex plastic tubing just for compressed air, with all the couplings and fittings to match, no tools required all pcs just slip together air tight. not home depot stuff, I got a little from a local pneumatics shop, to run an extension to the back of my shed. easiest to work with, not the cheapest.

 

[JoeL4330]

you might wish to check this out Eastwood Co. - 100' Garage Air LineKit w/ 12 Wall Mount Clamps

 

[Wombat125]

Don't know what it's called but there is a flex plastic tubing just for compressed air...

I'm guessing you're talking about the RapidAir stuff. I just bought 200' of hose and couplings, but haven't plumbed it yet. We'll see. The price actually wasn't too bad.

Compressed Air Piping, Compressed Air Systems, Do It Yourself Air Tool System

 

[czechsonofagun]

If your looking to use a flexible air tubing to plumb your shop why not use air brake hose. Get a spool of Synflex DOT rated truck air brake hose and plumb away. It is rated for air, is UV resistant and safe in cold temps. It's what I plumbed the air system on my mobile service truck with.

Good idea, i used copper, but if I have to extend, I will use that.

 

[ray66v]

Unless you have a really good air drier, you want to slope your lines back to a point you can have a drain, or drains to get out the condensation. I have found one at each "drop", (hose attachment), and one at each end to work well.

That being said, I am wondering how you get coiled plastic pipe to "behave" well enough to do this, on the horizontal runs. Coiled pipe does not usually like to lay flat without a fight. You will likely have to have wood backing it up the entire run, and lots of clamps. Even a slight belly will accumulate water, and release it, usually all at once, on a high demand air draw.

 

[ctpres]

I just ran PVC and pushed reg air thru it. Did this underground, crawl space and over rafters. Lots cheaper than copper or steel pipe and much easier to install.

 

[ray66v]

I just ran PVC and pushed reg air thru it. Did this underground, crawl space and over rafters. Lots cheaper than copper or steel pipe and much easier to install.

Here starts the heated part.

It's also not very safe, and not code. Maybe you know a million people who have done it, so do I, but many have been injured by it, some seriously. I personally have been injured by it, and have also seen it break and injure someone fairly seriously. That's why PVC air lines are an OSHA violation.

I would not use PVC at all, as pressure pipe, if your going to use it anyway, use a rubber hose between the compressor, and the line, to isolate vibration, and switch to steel pipe well before you attach any hoses. Be sure to anchor the steel lines to the walls thoroughly. That way if a hose is yanked, it can't break the plastic pipe.

 

[schmism]

Ive used 1/2" PVC in the past with no issues. Thats not to say there cant issues but thats no diffrent than any of the other stuff we own and use.

 

[MrWoodChips]

Ive used 1/2" PVC in the past with no issues. Thats not to say there cant issues but thats no diffrent than any of the other stuff we own and use.

What you do not realize is the failure mode. PVC with air will supposedly shatter if there is a problem. Do you want the undertaker picking sharp pieces of PVC from that wound in your throat?

Copper will just split. No problems.

Hey, it may not happen to you. It seems a silly thing to risk your life or your eyes though.

John

 

[JB4310]

I wouldn't think PVC would be safe for Higher pressures, never heard of anyone using it before here, I've done some runs with standard 1/2" sweated copper tubing and fittings, been told that's not really kosher either. I'm only around 140psi max.


Compressed Air Piping, Compressed Air Systems, Do It Yourself Air Tool System

Yea this is the stuff I was talking about (Wombats link) looks like the way to go, that $139. kit looks like a good deal, I like those wall mounted couplers.
JB

 

[ray66v]

I wouldn't think PVC would be safe for Higher pressures

PVC has high enough pressure ratings for compressed air, that's not were the problems arise.

The problems are the heat, vibration, breakage from a sudden shock, and chemical breakdown, due to contaminates in the compressed air.

I once worked in a Body shop with PVC airlines, and saw the problems first hand.

I have seen pipes break. But, I have not seen any shatter as has been reported.

Some simple research will turn up many documented cases of accidents involving PVC pipe and compressed air. There is no question it has been proven to be dangerous.

The analogy that you can repeatedly cross the street without looking, and not get hurt, that does not mean it is safe, was once made here about using PVC pipe for air lines.

I would not use it at all. But, if you want to limit the risk, use it with the stipulations I made in my previous post. They were all done as a result of failures, and did eliminate those problems.

Using PVC pipe is, just like crossing the street without looking.

 

[john_bud]

Couple years back the pvc line in my shop exploded while I was in there. No warning, just a hugh KaPow! Shards of PVC went everywhere and the shop was instantly filled with a cloud of vapor from the moisture in the line. I was using a grinder at the time and had ear muffs on. It was also winter and I had on insulated coveralls. No damage to me.

When I cleaned it all up and took out the pvc, it was shocking how brittle the pipe had become over the years. I mean some of the pipe was real real easy to shatter just by stepping on it or pulling it from the wall. It could have been ugly hitting it with a stay tool or whatnot.

The shop is all iron now. Costs more, but it won't shatter.

 

[Pilot]

I also had pvc shatter. First you hear the explosion with everything flying around, then almost instantly the air bleeding off, then the compressor comes on, almost everything at once. One heck of a surprise.

My shop has all copper now.

If you use something flexible, as someone mentioned, you want all your lines to drain with no low spots where water could collect from condensation. And you might get it set up OK, but will it sag over time?