Pex tubing for Compressed air?

A recent Residence Hall contruction at the University where I work ended up with a "pile" of Pex tubing cut-offs. Some quite long (50 feet?). This and the many debates over copper vs iron vs PVC has me wondering about the practicality or pros and cons to using Pex to plumb Compressed air in a shop. So three questions come to mind;

1) Any one out there done this?

2) In relation to other materials how expensive would Pex be? I have the pipe for nothing and access to the $300 tool so that's not an issue for me. The cost of the fitting and the ease of attaching hose fittings comes to mind.

3) What are the pros and cons of the physical application? The pipe itself is certainly cheaper than copper. It wouldn't be as puncture proof as iron but the perception of the likelyhood of it shattering under pressure that seems to be the worry with PVC doesn't seem to be there. etc.

Thanks in advance,

Mike

I did a google search on PEX and it would appear that it is not considered suitable for air applications. It is also noted that it is for indoor use and if stored outside should be covered. If the throw aways have been exposed to UV, etc. that might render them unfit for any application.

Quote:

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Originally Posted by Ray Moser

I did a google search on PEX and it would appear that it is not considered suitable for air applications. It is also noted that it is for indoor use and if stored outside should be covered. If the throw aways have been exposed to UV, etc. that might render them unfit for any application.

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Depends on the particular type, some tubing has a secondary covering (it is usually white, depends on the manufacturer) that incorporates a uv block.

I also have a bunch of pex left over from a radiant floor install I did on my house. The tubing itself would work fine, but I decided against it. The tubing is not rigid enough, so it would make for a sloppy installation at least for exposed work.

Cheers,
Bernhard

There is a PEX type product designed specifically for air but I do not think that PEX designed for liquids is something I would want to use for pressurized air lines.
PEX lines are not expensive, it is the fittings that cost.

Quote:

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Originally Posted by Ray Moser

I did a google search on PEX and it would appear that it is not considered suitable for air applications. It is also noted that it is for indoor use and if stored outside should be covered. If the throw aways have been exposed to UV, etc. that might render them unfit for any application.

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I forget too frequently that Google is my friend. ;o)

So, I too Googled PEX and although I didn't specifically find compressed air listed as a PEX application I didn't find a place excluding it either. Did you find a link saying this was a bad idea? or did you not find a listing where the application was called out?

mlw

Personally I use copper. I used PVC a long time ago and had a little incedent. We had a dart board in the close proximity of the pipe. One day someone threw a dart and hit the pipe. It exploded like a gernade and shards went 50 feet from the explosion. fortunately no one got hurt but this could happen if anything were to hit the pipe. I would strongly recommend not using any kind of material that this could happen to. With copper it's only going to get dented or a hole in it. IMHO stay away from plastic.

The other nice thing about copper is if you decide to make changes later you don't have to thread anything. You just cut, solder and go the way you want.:)

If I remember it correctly, Pex-AL-Pex, is the pex aluminum combo tubing sold and rated, for air line use. When I looked it up a couple of years ago, it was a more expensive option, without the benefits of the metal pipes.

I went with Black Pipe, put a slight angle to allow drainage. Cheap, easy to use and almost bullet proof. If you don't have access to a threader, a purchase at HF should not cost much ( although I seem to see them all over the for sale ads these days at really low prices).
I have mine for 10 plus years with no issues.
Robert

I am one who used PVC and have had it for yrs.But,I would NOT do it again,I would use either copper or black pipe.Unless you need to run alot of footage,the cost is small either way.And it will last you alife time and having piece of mind knowing its safe.

I'm not sure what PEX is made of, but HDPE works great. Guest fittings to transition to 1/2 copper so to have a rigid connection to a quick connect, in an unheated hangar, have work great these last three years.

Jim

I did a heated concrete floor for a guy just last week and we installed PEX tubing in the floor. It is made for this and if I remember correctly the tubing states right on it not to exceed 80 psi. I usually put air in the system when we are pooring just to make sure that we don't puncture the tubing while pouring the concrete. I wouldn't use it myself. I used copper 3/4" in my shop. It works great and it isn't that expensive and the fittings are cheap.

My two cents

Ben

Mike, I don't think this would be advisable for compressed air systems...too much of a chance of the lines exploding. You would be better of using galvanized pipe and threaded connections for an air system. A bit more trouble to install at the outset...but won't give any trouble either. I tried to use pvc, a short run on my compressor, in no time it split the connections and blew it out...went back to the galvanized iron pipe and glad I did. Jim Heffner

I've seen some aluminum tubing used in industrial factories... it uses "push fit" style fittings. No threading, no sweating copper, no worries about UV exposure, moisture eating away at black pipe or darts! LOL.
Cut your alum pipe to length, push on the 90* elbow, Tee or coupling or whatever and go on to the next piece.
I don't have a clue as to cost, but I do know installation is a breeze which certaily has a price.:rolleyes: And I've had to buy some Kaeser compressors and air prep stuff, it's not HF priced to say the least.
Something like this:
http://us.kaeser.com/Products_and_So...wyAXdUnzPChZzi

Cheers,
Greg

IPEX makes a product specifically for air. It is called DURATECH.
Web site:
www.ipex.com

Look under industrial products-compressed air.
That's what ya want.
Bill

There is a product specifically designed for air that uses aluminum sandwiched between layers of HDPE. Here is the link:

http://www.ipexinc.com/Content/EN_CA..._2_Duratec.asp

It is easier to work with than either copper of pipe and cheaper than either.