Shop Air Supply Lines

I would like to here what everyone is doing for air lines.

My setup will be small, only a 2 car garage. I have worked in auto shops for 40 years and scene every setup you can imagine, and yes I have seen PVC that exploded so that will not be road I will go down.

Seems like a lot of people are using PEX A, not meant for compressed air but I’ve seen burst testing videos where it easily handles 300-400 psi. That looks inexpensive and easy to do. RapidAir has mixed reviews, leaking issues and quite a bit more money. Considering I only have maybe 50’ in total the cost should not be much of an issue either way. Likely will only have 2 drops. I’m planning for 1/2" right now but should I go 3/4"?

Or just go galvanized.

I won’t see my table for a while so I have time to plan.

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In my experience, RapidAir only leaks if you do not insert the tubing into the fitting completely or cut the tubing square. Beyond that, I’ll let others offer their thoughts on your requirements.

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I’m thinking copper for 50’ in 1/2". Reason is the copper might help cool the air some - but other than that, pex is easier to run for sure! I’ve got a 50’ reel hose (3/8") that I’m using to get the reach I need. I’ve been eyeing the rapid air system as a future upgrade.

Just my thoughts - I’m in a 2 car garage as well.

As far as 1/2 vs 3/4 - I’ve looked up the air flow charts at 1/2 and it’s flow rates are much higher than any pretty big non industrial compressor can handle out to 100’. If the line will be over 100’ at 15CFM, you should go 3/4". But if you’re like me and overkill everything, just go 3/4" :grinning: - but 1/2 is plenty and no need to waste extra $$$.

Some good sizing info:


Those charts are great. Looks like 1/2" is more than adequate.

Still shopping a compressor as well, was hoping to find something decent used but not having any luck locally.

I bought 20 feet of 3/4 inch copper pipe and 20 feet of 1/2 inch. The 3/4 inch will be between the compressor and the compressed air dryer for the reasons James5 stated. The compressed air dryer wants an air temp of 175 degrees or less. I’ve seen other sites that talk about 20 feet of pipe between compressor and the compressed air dryer for cooling purposes. The 1/2 inch will be the supply line for the drops.


not to hijack a post, but what would you guys use to go from a single car garage where the compressor is at to the 2 car garage where the table is at. I currently have a 50’ hose that i have to uncoil when i need to cut something and coil back when I’m done. PITA.

I was thinking maybe running galvanized or black pipe under the dirt and walkway between the 2 garages and come up a foot or two on the outside walls, make a hole and plumb it on the inside of both garages.

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I’ve got rapid air and iits works great for me.I bought the kit and have spare line for future expansion if needed.


That sounds like a good plan - galvanized in the dirt if it’s going to get wet when it rains. You could run copper underground as well (or pex). But a retractable 50’ hose reel is about $80-100 and makes hose management much easier. I got one recently and don’t know why I didn’t get one years ago.

I think I would use pex underground.Its cheap!

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things to keep in mind…when using most lines that require mechanical fittings…PEX…Sharkbite…or other compression fitting you are reducing the interior diameter of the lines.
in reality a 1/2" PEX line when you use a coupler or an elbow you have reduced the inside to 3/8" or less.
most people will not notice the difference…but if you have to use a lot of fittings to get to the end of the line that is a lot of restriction of air.

run the 3/4 PEX if you must.

I’m using a mix of black iron pipe and pex-A. I’m a fan of PEX for sure, super easy to use, not likely to leak either, but it has to be shielded from UV.


I also bought a kit. 1/2 Maxline (200psi) Master kit. Pretty complete with 100’ , couple drops, manifold, valves, fittings for around $150


When I finally get around to doing my garage I’m just going to use plastic DOT airline for heavy duty trucks. You can get it pretty cheap and it’s easy to work with. Our equipment is generally set at 130 psi and we use it around the shop for some things up to 165 psi and never once had an issue. The only time I’ve seen it blow was being near a heat source and it’s gota be pretty hot at that. Like melting plastic hot.

I installed the RapidAir Maxline 3/4 kit. It was really easy to install and I have had zero leaks.


I’ve been running PVC for over 30 years with absolutely no issue. Don’t overthink the problem.

are you guys using 3/8" hose lines to the plasma cutter? or 1/2"? is there a big difference between the 2?

I used 1/2 pvc.
The problem with 3/8" is you loose some volume with fittings , especially quick disconnects. 1/2" is cheap enough.

i was asking about the rubber hose lines? unless you run straight pvc to the cutter?

i’m running a 50’ 3/8" hose from compressor to plasma but was thinking of going up to 1/2", and if I go the route of running a supply line from one garage to the other, maybe run that line with 3/4" pvc? the run is going to be about 40 feet.

This is what I have run from my drop to the plasma cutter.

I use RapidAir, 3/4" Kit, it comes with 3 manifolds and it has never leaked …

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