PEX for compressed air?
#11
I’m about to have a new shop and am considering using pex for air.

From what I have searched online it looks like it hasn’t been tested or approved for this but some folks are using it.

Some with good results and some with failures

I’m assuming that the most failure prone area is the connections
I’m also assuming that type of pex matched to type of connection probably makes a significant difference

Further I’m thinking that firmly fixed last pex to iron or copper so that your not jostling the pex connection should improve success.

Anyone have first or second hand experience with pex for air?


Duke
Reply
#12
(01-03-2019, 08:16 AM)JDuke Wrote: I’m about to have a new shop and am considering using pex for air.

From what I have searched online it looks like it hasn’t been tested or approved for this but some folks are using it.

Some with good results and some with failures

I’m assuming that the most failure prone area is the connections
I’m also assuming that type of pex matched to type of connection probably makes a significant difference

Further I’m thinking that firmly fixed last pex to iron or copper so that your not jostling the pex connection should improve success.

Anyone have first or second hand experience with pex for air?


Duke



Check out Rapidair, it's basically the same pex with an aluminum core and designed for the job of handling compressed air. The aluminum core makes the tubing a little stronger but also helps it to retain it's shape better You can straighten it out or bend curves and it will hold it's shape so it looks neater. Regular pex is hard to make look neat and nice, you have to anchor it often and it will still tend to snake around. You can find rapidair at northern tool or amazon, even my local bomgarrs farm store carries it.

The bigger problem with pex is since the fittings fit inside the pipe they  can be a little restrictive so you may want to use 3/4 or larger. The rapidair stuff uses compression fittings that are more open internally than the crimp on pex fittings. I have a run over to a hose reel on my ceiling where I have used 1/2 pex and it does seem a bit restricted. If I were doing it with pex again I'd use the larger 3/4". The tubing and crimp fittings are plenty adequate pressure wise for handling most compressed air systems. My system operates at 175psi and it's never been a problem. Much of my shop was done 20+ years ago with copper but that's too expensive these days.
Reply
#13
(01-03-2019, 08:16 AM)JDuke Wrote: I’m about to have a new shop and am considering using pex for air.

From what I have searched online it looks like it hasn’t been tested or approved for this but some folks are using it.

Some with good results and some with failures

I’m assuming that the most failure prone area is the connections
I’m also assuming that type of pex matched to type of connection probably makes a significant difference

Further I’m thinking that firmly fixed last pex to iron or copper so that your not jostling the pex connection should improve success.

Anyone have first or second hand experience with pex for air?


Duke

I used PEX for much of my layout.  My compressor is in a garage next door to my shop so the runs were long and Pex was cheap and easy.  I kept the pex up in the truss space and in the walls and switched to copper where it was exposed or where sunlight or heat would hit the pex. 

I've also added a remote pressure switch to depressurize the lines when I am not in the shop so the pex does not have pressure when unattended.  No issues in 10 years.

If you use it... avoid exposing the pex to sunlight and impact damage.
WoodNET... the new safespace
Reply
#14
(01-03-2019, 08:16 AM)JDuke Wrote: I’m about to have a new shop and am considering using pex for air.

From what I have searched online it looks like it hasn’t been tested or approved for this but some folks are using it.

Some with good results and some with failures

I’m assuming that the most failure prone area is the connections
I’m also assuming that type of pex matched to type of connection probably makes a significant difference

Further I’m thinking that firmly fixed last pex to iron or copper so that your not jostling the pex connection should improve success.

Anyone have first or second hand experience with pex for air?


Duke

I agree with Splinter, although in my shop I don't have much sunlight let in.  I also don't have as much experience as I am going on 2 years of having PEX air lines.  I also used shark bite/gator bite fittings in lieu of PEX fittings (not approved for compressed air, but have been doing OK).  I made sure to put my clamps near the fittings so that they can't shoot off and cause injury, should they fail.  For my final connections to air regulators and beyond, I used threaded brass fittings. 

One big upgrade I did was to pretty much convert most of my tools over to 3/8" QC fittings over the typical 1/4" QC fittings.  While its not needed for most of my tools, I figured it did not cost much more to do so although I only needed to do it for my HVLP spray guns and sand blasting booth.  The only issue is that I was only able to find 3/8" Universal QC coupling at Lowes for a reasonable price because before I found out that Tractor Supply carried both automotive style and industrial style (I recommend standardizing automotive style in either 3/8" and 1/4" because they tend to have slightly larger orifices over the industrial in their respective sizes) fittings in 3/8" size, I was only able to find 3/8" QC fittings with 3/8" pipe thread at the local Northern Tool but only in Industrial style while the 1/4" pipe thread to 3/8" connectors from HF were only sold in automotive style.  But I did plumb a 3/8" universal and 1/4" universal QC coupling at each drop so I can use any tools I didn't already change to 3/8" or on the off chance a friend or relative needed to use my compressed air system, they would be able to.
Paul
They were right, I SHOULDN'T have tried it at home!
Reply
#15
I ran Rapid Air lines in a shop and it was easy and not expensive. The savings between PEX and RA aren’t worth it to me. I’ll run RA in my new shop too.
Reply
#16
I also used Rapid Air and I am quite happy with it.
Reply
#17
BloomingtonMike, a member here, used the RapidAir I believe. See his shop build thread.
Steve

Missouri






 
The Revos apparently are designed to clamp railroad ties and pull together horrifically prepared joints
WaterlooMark 02/9/2020








Reply
#18
From description of rapidair it looks like it’s essentially polyethylene tubing with aluminum like the air rated pex that was mentioned.

I like the idea of their fittings that sound like they take advantage of the air pressure to press the fittings more securely to the hose.

Duke
Reply
#19
(01-03-2019, 11:15 PM)JDuke Wrote: From description of rapidair it looks like it’s essentially polyethylene tubing with aluminum like the air rated pex that was mentioned.

I like the idea of their fittings that sound like they take advantage of the air pressure to press the fittings more securely to the hose.

Duke

Not all of it has the aluminum.  If you look at their website, the line of products they promote for home compressed air systems is plastic only.  

As far as the comment on Pex being only slightly cheaper than rapidair, it depends.  I happened across a special at Lowes where I think they were changing brands of Pex they were carrying and they were selling 3/4", 100' white Pex for less than $20.  My only regret was that I did not pick up the roll of 1/2" white Pex at the same time because when I went back they only had the orange/red O2 barrier Pex for radiant heating left, I ended up paying a little more for that roll, but still far less than a roll of normal 1/2" Pex.  I used the 1/2" for my drops.  Its a bit stiffer than normal Pex which made it a bit harder to bend.  Now I have a lot of leftover Pex that I am considering plumbing air in my garden shed.  The expense was in the fittings since I opted for shark/gator bites vs. the normal Pex fittings.

Paul
Paul
They were right, I SHOULDN'T have tried it at home!
Reply
#20
For the life of me, I'll never understand why people shy away from copper. Easy to run and bend, safer and good for a lifetime. No guessing if it will fail.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.