Air lines for the home shop

[Dave C]

I know this has been discussed before, but searching turned up no results. Somewhere I read that PEX pipe was ok for shop air as long as the line pressure did not exceed 100 psi. So today I'm thinking its time to run a line to my lathe that's been sitting in it's temporary location for nearly six years now, with no air handy to it. So I start looking up PEX stuff, and Sharkbite seems to be the main player. However an FAQ on their website says PEX is not suitable for air lines. Would nylon tubing be a better choice, or should I scrap the plastic idea and bite the bullet and go with copper?

[Sparky_NY]

Yea, the search engine here on the site leaves a LOT to be desired. There have been many lengthy threads on air lines in the shop. I searched "PEX air lines" and the ONLY keyword the search USED was "lines", apparently words 3 characters or less are ignored in searches. Wonder if that is something George could "tweak" ?

[lakeside53]

Simply, if you do not care about code you can do what you want. PEX as in water pipes is NOT listed for air use and cannot be code compliant unless your local jurisdiction allows it (unlikely).

Personally, I use copper, but there are some amazing "plastic" system rated for air, but.. if you use synthetic oil in your compress, check if the piping is suitable.

[lakeside53]

You can search this site with goggle. Use the SITE: syntax

How to Use Google to Search Within a Specific Website: 14 Steps (wikihow.com)


or just do this : site:bbs.homeshopmachinist.net/forum/general pex

[epicfail48]

Been a while since I checked it out, but my very fuzzy memory is that normal pex piping isn't suitable for air pressure, but there exists a hybrid aluminium/pex pipe that is. Can't remember what it's called though...

[chipmaker4130]

Got a truck supply house near you? They have assorted 'plastic' air line and fittings, and it isn't very expensive. Personally I like copper both for its ability to hug the wall without strapping every two feet, and for the thermal conductivity which aids in condensing out water (naturally you need sloped lines and drops at the low points).

[woodenbird]

Try searching for RapidAir 90500 systems. This is made for small shop air systems.

[Ohio Mike]

PEX isn't listed for compressed air, and isn't UV stable so it shouldn't be exposed to sunlight.

[jmm03]

Dave, this is one source for air rated PEX, but I think you would be better off using copper. (you can also use sharkbites on copper if you don't want to sweat the joints) https://www.globalindustrial.com/p/p...SABEgI1JfD_BwE Jim

[Tundra Twin Track]

I have over 500’ of Pex lines and 30 crimps in my shop that is 10 yrs old now running 155 psi with zero issues.My boiler friend that has installed miles of Pex kinda laughed when I questioned him if Pex would stand up his reply was it rated for 100 psi at 160 Fahrenheit and burst spec would be over 200psi at that temp.None of mine has direct sunlight on it.

My neighbour built a new shop and installed the pricey made for airlines and had grief with leaks at connections,I don’t recall what brand but it was one of high quality brands.

[darryl]

I did my system using air hose. The drawback is the relatively small ID., plus the fact that it's flexible and doesn't hang well without a support every 8 inches. But it is made with a fiber braid which means it won't blow apart into fragments like pvc can. I don't know about pex, but it's just plastic with no reinforcing, so if I had my choice it would be air hose, or copper.

[Cuttings]

I would second the truck air lines. The lines and fittings are readily available, easy to work with and it comes in a few sizes. I would go with one of the larger sizes so you don't get any flow restrictions.

[Ringo]

I re-plumbed my house with PEX. I also did a freeze burst test with it. I completely filled a short section with water and crimped the end on, left it in the freezer.
you could easily see it was frozen and swelled up, but it did not burst.
God only knows where the pressure was.

common steel pipe works also for shop air

[Doc Nickel]

I have roughly 250 total feet of both 3/4" and some 1/2" Rapidair Max Line in my shop. A total of eight drops and eleven outputs. It's been pressurized 24-7 for over two years now, and if I'm not using the air, the compressor might run on it's own maybe once a month.

A single Max Line kit is less than $200. A similar size and features setup with regular PEX will be not too far from that. Personally, I'd rather spend the extra twenty bucks at most, to have a setup designed for compressed air.

PEX will work- it's far and away better than PVC, and some idiots still insist on using that these days- but the Rapidair aluminum-lined PEX has a higher pressure rating at a higher temperature, and a better UV resistance.

Doc.

[darryl]

I just remembered- I now have a second air system installed, one for my paint booth. Even with the home made drier module, there is no leak down- my compressor doesn't start more that once every couple weeks if I'm not using air- and this isn't a large tank either. Plumbed with Ultra Tundra Arctic Flex or whatever that stuff is called. Comes in nice colors too