Using Pex on an airline?

[dmascheck]

Just curious to know if anyone has tried routing Pex tubing for extending your airlines in a shop? Just curious!

 

[Rockyhud]

I'm not sure of the pressure rating(s) for Pex, but I also haven't seen or read where Pex has been used for that purpose. I'm in the process of getting compressed air lines setup from my 80 gallon compressor, mainly to supply my plasma cutter but also for general use, and I'm going to use thick walled 1/2" copper tubing. The compressor outputs 175 psi so I'm filtering it first then immediately regulating it down to 90 psi which will be available at all the ports that I'll distribute in the garage. The air coming from the compressor will connected to the filter using a 1/2" rubber air line rated at 300 psi, so that will take are of 2 things - it's flexible so compressor vibrations won't cause stress on rigid connections and its pressure rating will easily handle the 175 psi output. BTW, the first device on the compressor is a 1/2" full throat ball valve so it won't restrict the air flow volume and the rubber line connects to the output side of the ball valve.

This copper tubing is surprisingly inexpensive when bought in 10-ft lengths and its working pressure is well below the 90 psi it will be used with. If you go this route, just be sure you check the rated pressure as there is a thinner walled tubing that isn't rated for high pressure. Here's a link to Lowes for copper tubing that meets the pressure requirements, at least for me. It's 10-ft long and has 200 psi max pressure rating.
https://www.lowes.com/pd/Mueller-Streamline-1-2-in-dia-x-10-ft-L-Copper-M-Pipe/1000227967

Now, if you're trying to keep your air lines flexible throughout your shop, so you don't have to deal with corners and bends and such, you might consider using the high pressure rubber air line like I used. I simply searched Amazon.com for this and was really surprised how inexpensive this was too. It's available in several lengths and diameters.

 

[weighit]

Not knowing what your going to be running with your air, only one item at a time then no problem. But if your planning on running more than one item that consumes air at a time, run the air line out of the filter your installing in a loop. Helps keep even pressure throughout the line. I used to have a 800 cfm compressor running 4 items, without a loop one of the machines was always running low on pressure. Installed the loop and all was well. We also used copper lines. Never saw anyone use the Pex for air, but I suppose it would work if the pressures were below the burst point.

 

[Rockyhud]

Thanks for chiming in, Stacey. Hadn't thought of that but it makes perfect sense. For my application, the plasma cutter will most likely be the only thing running at any given time, but there could be exceptions.

 

[Notanlines]

Don't forget the pressure drop along a line that small trying to maintain air pressure. Better look at the chart.

 

[dmascheck]

I notice Northern Tool has an air line set up that uses a blue plastic tubing! I think it was rated at over 100 PSI. I need to check! I'll be running only one thing at a time and really just wanted to run a line to the outside of my shop to air tires on equipment nothing else.

 

[Porkchop-THOR]

Pex is rated at 300 lbs. Printed on it. Cheaper than copper and easier to work with. Weak point would be fittings if not installed correctly.

Bill

 

[Rockyhud]

Pex is rated at 300 lbs. Printed on it. Cheaper than copper and easier to work with. Weak point would be fittings if not installed correctly.

Bill

Maybe some Pex is rated that high but not all. This one is rated 160 psi max pressure. Just goes to show you need to be careful and aware of what you chose to use for what purpose.
https://www.lowes.com/pd/Apollo-1-2-in-x-5-ft-PEX-Pipe/1000203085

 

[dmascheck]

Id never have a need for 160# of pressure so apparently it could work for 120 or so.

 

[Rockyhud]

The main reason I posted the Pex with 160 psi rated limit is my garage compressor outputs air at 175 psi before any external regulator comes into play. If someone were to inadvertently use 160 psi rated Pex directly on the output of a compressor such as mine, they would not like the outcome once it got up to pressure.

 

[dmascheck]

I understand and you are correct. Mine is a low application and I can set my switch to different pressure settings.

 

[Rhagfo]

When I plumbed my garage for air with a 125 psi compressor I use schedule 40 PVC rated at 200 psi, low cost and easy to work with.

 

[MorganT69]

We have air lines ran all over our shop with PVC, been working for years that way.