Pex for central compressor system?

Jeff2413

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I just put an addition on my shop which includes a dedicated spray room and additional storage/overflow space.  It's an additional 12x48 on the side of the original 24x48.  With this build I have added a 60 gallon air compressor which is in the storage unit along with dust collection to save space and noise.  Has anyone used the PEX to create a central system for air? I've read of this being done and it seems very doable other than I can figure out how to mount a quick connect to the wall.  I can buy a 100' rolling PEX for $25 and the fittings are fairly cheap price can fork out about $200 for the Rapidair system. I have a sander and a paint pump that require permanent air and also want about a couple of quick connects for sander/nailer/blow tip sorta thing.  Don't mind spending the $200 if that's what I need but I love saving money anyway I can if I can get the same results and pick up all my parts and the orange store.
 
Although there are numerous videos out on the internet that show how people have done this you might be best served to check with the manufacturer of the pipe and fittings for applicability.  You mentioned the orange store.  I know that they sell the Sharkbite brand and a quick Google search brings up that there system is for water only.

Hope you find one that works for you.

Peter
 
Jeff, what diameter tubing are you planning on using?
Hans
 
you might try www.jhfoster.com
they have an answer to every compressed air connection I have ever asked them.
Hans
 
FWIW...if this were my project, I'd consider using 3/4" instead of 1/2" because of the pressure drop.

Also, larger 60 gallon compressors are usually 2-stage and put out 175 psi while pex is rated at 160 psi at ambient temp. The output will need to be regulated.

Here's some additional info:http://www.pexuniverse.com/pex-tubing-technical-specs
 
bigger diameter piping takes no more labor to install than smaller. My vote is for "bigger" - that larger piping volume will also serve as an additional air storage tank.
Hans
 
I'm leaning towards the 3/4" Rapidair which is an aluminum core or just hard piping it. 
 
Jeff2413 said:
I'm leaning towards the 3/4" Rapidair which is an aluminum core or just hard piping it.  

Good that's a better decision, I'd use either black iron or copper. Don't forget to install it at the correct angle, add condensation drain legs/valves and remember to tap off of the main line from the top side of the run.
 
The Rapidair is great stuff and easy to use plus there is no internal rusting as with iron.
 
I always do my air line in 3/4" "L" series copper pipe. Easy to work with and modify as needed. Drops with valves are easy to install. Cost is fairly minimal. If doing a really long run I would recommend adding in an al80 scuba tank near the end drop, butt end up for some extra air capacity, or do the run in 1" pipe. (Before someone mentions hydro: Rated for 3,000 psi it will most likely never blow at under 200 psi.)

Although galvanized pipe is strong, it is harder to modify and work with...especially if you don't own a threader. I have seen it rust internally, and combined with the rust in the air tank, blow out some seriously nasty water.

A high quality filter is important. Not one of those cheesy HF ones. The Motorguard ones are nice after a water trap, if you are looking for reasonably clean dry air. I run one for my plasma cutter, and when spraying.
 
Peter_C said:
I always do my air line in 3/4" "L" series copper pipe. Easy to work with and modify as needed. Drops with valves are easy to install. Cost is fairly minimal. If doing a really long run I would recommend adding in an al80 scuba tank near the end drop, butt end up for some extra air capacity, or do the run in 1" pipe. (Before someone mentions hydro: Rated for 3,000 psi it will most likely never blow at under 200 psi.)

Although galvanized pipe is strong, it is harder to modify and work with...especially if you don't own a threader. I have seen it rust internally, and combined with the rust in the air tank, blow out some seriously nasty water.

A high quality filter is important. Not one of those cheesy HF ones. The Motorguard ones are nice after a water trap, if you are looking for reasonably clean dry air. I run one for my plasma cutter, and when spraying.

This is what we do also.  Super easy if you have a little experience soldering copper already.  Totally agree with all the above.
Motorguard and Coilhose are my brands of choice.  I've also used copper unions that make it quick to take out a run if its in the way.  Air fitting thread, 3/8" NPT?, by 1/2" copper fittings are available, I think they are used in refrigeration work.
 
I would stay with the proper product for the application,  I have had fitting fail with the right materials and had it cause a large amount of damage.  Glazing in a custom door,  big dollars to replace, gotta love employees.  Also on a safety note, do not drag the air compressor by the hose.
 
Samo said:
I've also used copper unions that make it quick to take out a run if its in the way.

And if you have a difficult time keeping the union from leaking, just apply a thin layer of Rectorseal #5.
 

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I don't trust most Pex crimps except these at Lowes . I have done bathroom remodels where, when I have interacted with copper crimp rings, they've given out. Stainless is the way to go. That said, I have a hard time picturing Pex withstanding most air compressors, unless you have a regulator I suppose...
 
I have a lot of love for Pex pipe and the benefits it provides (freeze-thaw resistance, high pressure, flexibility).  However, I asked my father, a plumber, this same question about using Pex for compressed air, and he had a fairly substantial warning.  Standard Pex pipe is designed to be buried in a wall, with no exposure to UV light.  I was warned that unless otherwise noted in the specs, most Pex pipe is going to degrade with exposure to UV.  Virtually every compressed air piping system I have seen has some point in the setup that is exposed.

I am pretty skeptical about the Sharkbite fitting system.  I prefer the Wirsbo fittings because the theory behind them makes a million times more sense to me, with little or no risk of failure.  The crimping collar is made of Pex and has a memory.  The expander tool warms and stretches the fitting to a slightly larger diameter than the pipe.  When the collar is slipped over the pipe at the fitting location, as it cools it attempts to return to it's original (undersize) diameter.  This means that the fitting is under constant pressure.  Unless the fixture is reheated, the pressure will exist beyond your lifetime.  The tool isn't cheap (about $400), but some places have them for rent.  The collars are about thirty-five cents apiece.  Between the tool rental and the collar cost, that's cheaper than my time attempting to solder copper.  Others may find the price/performance balance of copper to be more in their favor.

There are good points above about drainage that apply to any system of any pipe type.  I also agree about filtration, although I'm always willing to invest in the ounce of prevention.  The last system I set up from scratch was copper (customer choice) but I added the Dynabrade FRL units to each shop outlet.  This system was really designed for sanding, though.  In another shop, where the air was also supplying a CNC, we went with a separate appliance to dry the air.  Cheap insurance.
 
How about industrial pneumatic fittings from Festo/SMC/Norgren?  Used in most industrial factories around the world, can easily mix fittings from different suppliers.  Even if you don't get discount from your local supplier, surplus stock is always turning up on ebay.

 
My buddy built a garage 30 x 40 16 years ago. Ran 3/4 glued pvc for his compressor thru the whole shop and to date has never once had water rust or any problems. They are routed in the studs just like wiring. When things are done correctly the best materials are the ones your comfortable with. Only issue with PVC pipe is you have to anchor the pipe very solid where your quick connects are going.
 
I've done that once before.  Years ago.  Ended up having to use a flex line for about a foot and then the pvc due to vibration.  Kept breaking that first joint loose.  For right now I bought about $12 worth of black iron fitting and made myself a 3 prong union with shit off valves for each line.  One for spray.  One for wide belt and the other for hand tools.  This will get me by until I can decide what I wanna run.  Something flexible would be way convenient.  My shop has a 4/12 pitch which makes it nearly impossible to push something down the wall from above without using a snake.  And a snake won't work so well on rigid iron or PVC for that matter. 

Thanks for your input!
 
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