PVC and PEX for Compressed Air

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Hunter79764

Full Access Member
Joined
Sep 1, 2021
Posts
344
Reaction score
531
Location
Grand Prairie, TX
First Name
Shawn
Truck Year
1987
Truck Model
Suburban V20
Engine Size
350
Just a note that might be helpful info for folks wanting to run compressed air as cost-effective as they can...
I've heard good advice about PVC pipe not for use in compressed air systems, being that if/when it fails, PVC shards can be sent at high velocity through the neck of whoever happens to be in the way, but beyond that it seems to be unclear. In some unrelated air compressor research, I found a reference to recommendations from the Plastic Pipe Institute and their recommendations on the matter (see link below to get the source, 2 PDF's attached as well).

It states thermoplastic pipe should not be used for compressed gasses unless it is shrouded or otherwise protected, but does not "Ban" it unless covered by local code. Personally I take that to mean buried lines are ok since the shard potential is gone, and same for running pipe in stable locations where there is not a direct line from the pipe to people nearby (i.e., I'd feel relatively safe running in my metal building Z Purlin at 8' high). This is also in line with the other issue on PVC of UV exposure causing brittleness since anything shrouding the PVC is also likely to block sunlight.
This is common general advice out there, but again, here it is in writing even if it is between the lines. That said, PVC is not very durable, and even if it is safe buried underground, man it would suck to have to dig it all back up when you run a heavy truck through the area and crack a line. And even if the piping is not Line-of-Sight, a shard can easily ricochet and still cause problems.

What is interesting to me as well is the advice on pressure testing PEX with compressed air. To my knowledge, no one has approved PEX for compressed air, but this group draws a comparison between plastic pipe that breaks brittle vs PEX and PE-RT that remains flexible. Air testing PVC water lines is generally a no-no, but this recommends/allows air testing of PEX systems. Note this is not approval for use with compressed gasses so don't use this as evidence for your friendly neighborhood code inspector, but if it is "safe" to test with air, I feel safe using it for distribution in my own shop. It does have some good practical warnings about being careful of fittings and lines turning into whips in a failure, but a 3/4" or 1/2" PEX line anchored every 10' doesn't seem like a huge whip potential to me.


Anyway, just some info some of you might find handy and many might find boring...

 

Attachments

  • Recommendation B PVC with air.pdf
    66.9 KB · Views: 18
  • Recommendation F PEX with Air.pdf
    91.1 KB · Views: 18

Old Guy Bill

Full Access Member
Joined
Sep 10, 2023
Posts
429
Reaction score
1,327
Location
KY
First Name
Bill
Truck Year
1978
Truck Model
K20
Engine Size
400
The newest building at the mfg company I do maintenance work for has the AI-PEX all through it for pneumatic supply. It’s 1” blue, and has all brass fittings.
I’d never seen anything like it. It’s impressive stuff and the installation is top notch and I’m sure it was expensive. I’m trying to get some of it to add some ports needed as the business expands.
 

Hunter79764

Full Access Member
Joined
Sep 1, 2021
Posts
344
Reaction score
531
Location
Grand Prairie, TX
First Name
Shawn
Truck Year
1987
Truck Model
Suburban V20
Engine Size
350
Is it RapidAir stuff? I've looked into it before, and we used it for a small area of our plant construction a few years back. Material cost is higher, but I think I've seen where overall install costs (when done 3rd party by professional pipefitters) end up being similar since the labor is so much less. I'm probably going to use PEX for my workshop to pipe my air supply (power is first, and no real plan yet on that so I'm a long way out), but if the RapidAir comes down in price, or I get a few extra dollars in my pocket, it's on the short list.

We also use more rigid aluminum (also blue plastic coated) for our compressor rooms lately, same story, cost is not much more but labor goes way down vs welding 4" and 6" pipe everywhere... All of that stuff gets so expensive it's hard to compare. Basically have to add a few zero's to everything. I have a 2.5hp compressor, might upgrade to a 5 or 8hp in the right circumstance, probably could spend $200 on adding a used unit or something. Work has 600-900hp of compressors on most buildings, one shop in particular has 9 different 300hp compressors at $200k each...
 

Old Guy Bill

Full Access Member
Joined
Sep 10, 2023
Posts
429
Reaction score
1,327
Location
KY
First Name
Bill
Truck Year
1978
Truck Model
K20
Engine Size
400
I’m not sure of the maker.. I’m overwhelmed by the projects that I’m doing and haven’t had a chance to look into it.
 

waterpirate

Full Access Member
Joined
Jan 2, 2019
Posts
931
Reaction score
2,230
Location
delaware
First Name
Eric
Truck Year
1987
Truck Model
v10
Engine Size
5.7 tbi
It would be important to note here the service pressure. A high line vs. a regulated line is a whole nother bunch of grapes. Call me old fashioned but for a high line I want steel. A regulated line can be whatever you are comfortable with. I am also not a fan of shark bite or compression type fittings that often are used with the pex type tubing on high lines. YMMV
Eric
 

Latvius

Junior Member
Joined
Aug 14, 2024
Posts
2
Reaction score
4
Location
Ariton Alabama
First Name
Richard
Truck Year
1984
Truck Model
K30
Engine Size
6.2L
I use 1/2 pex in my barn/workshop with compression rings, installed a couple years ago. No leaks and no problems.
 

Tonimus

Full Access Member
Joined
Sep 17, 2024
Posts
63
Reaction score
108
Location
Phoenix
First Name
Tony
Truck Year
1978
Truck Model
C10 Suburban
Engine Size
454
We've had RapidAir line in the shop for a bunch of years now. Works great and install was super easy. It's terminated into overhead reels so it's all up on the ceiling.
 

Steelbuddha

Junior Member
Joined
Mar 16, 2024
Posts
16
Reaction score
14
Location
Central North Carolina
First Name
Jonathan
Truck Year
1984
Truck Model
K20 (dump bed)
Engine Size
350
My entire shop (3000 square feet) is plumbed with conventional 3/4" PEX with brass fittings and copper rings. Many drops. It's always charged at 125psi. Zero trouble in 12 years. (Note that the shop is conditioned space and there's no UV exposure.)

Years back I tested PEX air plumbing in a small outdoor shop. It would get well above 100°F in summer and freeze hard in winter. I figured if anything failed, it would be obvious where it happened what the conditions were. Nothing failed.

In the past I've gone through all the trouble of plumbing air using black iron and copper. It's become pretty clear that wasn't worth the extra effort and expense.

And unlike steel or copper pipe, I've seen no condensation in PEX. The compressor has an automatic bleeder on it and a copper precipitation coil (looks like a moonshine still) to remove condensation right after the tank.
 

Oldbear42

Supporting Member
Supporting Member
Joined
Feb 15, 2024
Posts
196
Reaction score
506
Location
Linden, Alberta, Canada
First Name
Shaine
Truck Year
1981
Truck Model
C20 LWB Scottsdale
Engine Size
350
I used a few Maxi-air kits, as they were on sale. It gave me some drop-down junction blocks that allow an air fitting, drain valve, and wall mounting. I've since replaced the cheap push-to-connect plastic fittings with brass push-to-connect fittings. This stuff is similar to the Synflex (or whatever brand you find) airline used in the trucking industry. It comes in different colours, but my kits were blue, so I stuck with that.

I plumbed the line along my ceiling with drops down to reels or wall mounts. I even ran a line underground to my attached garage so we could use the air system I had installed there before the shop build (also Synflex hose and fittings). It remains flexible and handles the UV light from my welding corner, the hot air when the compressor is running as I'm using it and the cold air when I open the big door in the winter. It allows for changes and reworks without much issue. It attaches to the wall with pex tubing clamps. The air drier tube was found a few years after I had the system in my shop - installed in less than an hour. I also got the regulator at the same sale - that one took longer as I had to think more and build a wall mount for something that wasn't built to be wall-mounted.

The airline from trucks is rated well over what our air compressors should be running at and made to handle temperature swings (highs and lows). I buy mine from one of my suppliers for work, but it can be found in many places.
 

Attachments

  • IMG_5220.JPG
    IMG_5220.JPG
    165.1 KB · Views: 25
  • IMG_0871.JPG
    IMG_0871.JPG
    124.3 KB · Views: 22
  • IMG_2568.JPG
    IMG_2568.JPG
    98 KB · Views: 25

Steelbuddha

Junior Member
Joined
Mar 16, 2024
Posts
16
Reaction score
14
Location
Central North Carolina
First Name
Jonathan
Truck Year
1984
Truck Model
K20 (dump bed)
Engine Size
350
I used a few Maxi-air kits, as they were on sale. It gave me some drop-down junction blocks that allow an air fitting, drain valve, and wall mounting. I've since replaced the cheap push-to-connect plastic fittings with brass push-to-connect fittings. This stuff is similar to the Synflex (or whatever brand you find) airline used in the trucking industry. It comes in different colours, but my kits were blue, so I stuck with that.

I plumbed the line along my ceiling with drops down to reels or wall mounts. I even ran a line underground to my attached garage so we could use the air system I had installed there before the shop build (also Synflex hose and fittings). It remains flexible and handles the UV light from my welding corner, the hot air when the compressor is running as I'm using it and the cold air when I open the big door in the winter. It allows for changes and reworks without much issue. It attaches to the wall with pex tubing clamps. The air drier tube was found a few years after I had the system in my shop - installed in less than an hour. I also got the regulator at the same sale - that one took longer as I had to think more and build a wall mount for something that wasn't built to be wall-mounted.

The airline from trucks is rated well over what our air compressors should be running at and made to handle temperature swings (highs and lows). I buy mine from one of my suppliers for work, but it can be found in many places.
I've gotta ask: What is the top-most tool mounted on your shop wall? The thing with the right-angle handle on it?
 

peats

Full Access Member
Joined
Dec 2, 2016
Posts
305
Reaction score
260
Location
Pennsylvania
First Name
john
Truck Year
72k5, 81c10 short step, 83k10 short fleet, 03 SSR. 25 chevy doodlebug
Truck Model
k5 c10 k10 SSR doodlebug
Engine Size
406 360 6.2 5.3 171
Keep in mind that PEX is UV sensitive. It's a good product within it's limitations. Not nearly as dangerous as PVC.
 

CountKrunk

Full Access Member
Joined
Aug 3, 2023
Posts
439
Reaction score
1,020
Location
SW VA
First Name
Count
Truck Year
1984
Truck Model
C20 Custom Deluxe 3+3
Engine Size
v8 350
i love pex and this makes me love it more haha.
 

waterpirate

Full Access Member
Joined
Jan 2, 2019
Posts
931
Reaction score
2,230
Location
delaware
First Name
Eric
Truck Year
1987
Truck Model
v10
Engine Size
5.7 tbi
I've gotta ask: What is the top-most tool mounted on your shop wall? The thing with the right-angle handle on it?
Pole digger/ line mans shovel with a mechanical advantage? The ones I have seen are handle only.
@ oldbear42?
Eric
 

plumtruckerd

Junior Member
Joined
Jul 30, 2023
Posts
20
Reaction score
33
Location
Pittsburgh
First Name
Mike
Truck Year
1986
Truck Model
C3500
Engine Size
5.7
I wanted to move my compressor into a shed that sits less than a foot from my garage so I didn't have to put up with the noise. I've been a plumber for over 40 years so I have PEX pipe and fittings so it was natural to use it. I ended up running about 30 feet on the outside of the garage around to where my workbench is. Now everyone wants about it being exposed to UV so I did it as a temporary line. It's been over ten years and it's still there. Zero issues.
 

Oldbear42

Supporting Member
Supporting Member
Joined
Feb 15, 2024
Posts
196
Reaction score
506
Location
Linden, Alberta, Canada
First Name
Shaine
Truck Year
1981
Truck Model
C20 LWB Scottsdale
Engine Size
350
I've gotta ask: What is the top-most tool mounted on your shop wall? The thing with the right-angle handle on it?
A garage sale find... it is a post-hole digger that lets you better scoop out the dirt in a deeper hole. The handle moves the shovel head 90 degrees.
 
Top