pex for air lines?

[phil harold]

I know there is rapid air system
but I saw a shop that had waterline pex for his airlines

pros cons ?
thanks

[Jim Becker]

PEX is designed for liquids and shouldn't be used for air lines. The tubing is "likely" ok, but the fittings are not, AFAIK. There is a similar product out there, however, that is designed for air. A lot of people do a lot of things that they probably shouldn't... In some cases it's merely risky; in others, it's merely life-threatening dangerous.

[Mark Hennebury]

Hey Jim, i resemble that remark.

Many years ago, i used a large clear plastic water filter as an air filter on my airline; it stated on the label that it could take up to 125 or 150 ( don't remember exactly) psi and i was only running 100 psi. so i figured what could go wrong.
It worked well for months, then one day it exploded, like i mean exploded. It sounded like a bomb. It sent huge chunks of razor sharp plastic shrapnel 100' across the shop. Luckily i was the only one in the shop and i was on the other side of the shop safely protected by large machines. My shop was in a huge old mill with dozens of other businesses, everyone on my floor came running to see what happened. So it was a little embarrassing.

The thrills and spills of the "lets give it a try and see what happens" mindset.

It was a similar filter to this one, i don't remember the brand.
watts_fh4200cw12_01.jpg

[phil harold]

frome a previous thread...

I sent an email to a company that supplies PEX (pexconnection.com) here is what he said when I asked about using PEX for compressed air in a hobby woodworking shop

" Air is routinely used for pressure testing PEX plumbing systems, and we use it here to distribute the air for our air compressor, so I would say that it should not be a problem for you to do that."

Then I asked about exposure to fluorescent lights in my shop. And his reply was:
"For best results, you will most likely need to cover it. PEX should not be exposed to direct UV light for more than 30 days. I will say, however, that the PEX we are using (for water and air) is exposed to direct fluorescent light and indirect sunlight and is performing well. Still, the recommendation is that it not be exposed to UV light."

I used PEX for the first time to move a toilet supply in our basement. It is so much nicer to work with than copper.

[Jim Becker]

PEX is all I use for supply line plumbing at this point, but if I were going to use something flexible in my shop, I'd opt for one of the purpose built products.

Here's what Sharkbite, one of the most readily available manufacturers of PEX products says about this:

Q: Can I use PEX pipe for compressed air applications?
A: No, PEX pipe is not intended for compressed air applications.

[Martin Wasner]

I had pex in my last shop for six or seven years. It worked fine.

Pros:
It's cheap
Super easy to modify.

Cons:
Zero ability to cool air down. I had lots of water issues.
UV supposedly breaks it down over time. I don't know how long that is.

[phil harold]

PEX is all I use for supply line plumbing at this point, but if I were going to use something flexible in my shop, I'd opt for one of the purpose built products.

Here's what Sharkbite, one of the most readily available manufacturers of PEX products says about this:

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sharkbite makes connections, not pipe



https://www.zurn.com/support

But it is okay to pressure test pex with air... check FAQ

Is zurn pex tubing OK for use for air compressor lines.
​Air compressor lines is not an application that's covered under our warranty so we can't recommend it. We have heard of people using Pex for this application but we have no data regarding longevity or potential problems.

[Mike Cutler]

I have installed miles of various types of "plastic" tubing in my career. Most is still in place 35 years later, and still airtight.
The con against using PEX is that the manufacturer doesn't recommend it for pneumatic installations, and the fittings are proprietary and expensive.

Look at Poly-Flo tubing and compression fittings. Much more product line flexibility for installations, and rated for pneumatics. I've installed reels of it.
No plastic tubing is going to be rated for direct sunlight, that a normal person can afford.

[Jim Becker]

sharkbite makes connections, not pipe

I have over 100' of PEX in my home that is labeled right on the product "SharkBite".

[phil harold]

I have over 100' of PEX in my home that is labeled right on the product "SharkBite".

my bad
I have only used thier connectors
pipe:
sioux chief
zurn
Nibco

[Steve Rozmiarek]

There are three different types of PEX, A, B and you guessed it, C. They are made with different processes, and have different amounts of crosslinking, which is what gives PEX it's toughness. Sharkbite and Nibco (and others)are B, some Apollo, Sioux Chief, Aquapex (and others) are A, C is generally considered inferior to A and B and I've personally never even seen it in the wild. A can use all fittings including expander, B and C cannot be expanded. Having used quite a lot of the stuff, I'd be comfortable trying some for airline, but I'd use A.

[James Biddle]

PEX is not rated for compressed air and PEX is susceptible to UV damage.

[Rollie Kelly]

When I put my floor heating system in, I used Pex-Al-Pex ( thin aluminum tubing lined and covered with Pex). It may be the same stuff Rapid Aire uses. It costs a little more than regular Pex, but, it is tougher than woodpecker lips. The fittings I used were brass compression type with nut, and "mucho Dinero". If I ever find my circular tuit, this is what I'll use. I'm not recommending just saying. YMMV!

[Jaromir Svoboda]

I had over 130' of PEX left over when I build my shop, so I used it behind drywall to run air thru entire shop, works just fine.

[Steve Peterson]

I have a Rapid Air system running through my shop. The pipe looks a lot like PEX. Both are flexible so they should not shatter and explode if there is a puncture. PEX should be safe in this regard.

Others have already mentioned that the fittings are not rated for air. This might force the compressor to cycle more often.