Shop Air Compressor Piping?

[Steve Mathews]

Part of my efforts to reorganize and setup a shop in my barn includes running air compressor piping. My thought was to run a loop around the entire inside exterior walls, which amounts to a little over 200 ft. After doing a little reading it looks like my logical choices for the type of pipe are black steel, copper and the coated aluminum pipe specifically for compressed air. I'm able to do the black steel and copper easily enough but still haven't decided which direction to take. I like the idea of copper for the ease of making changes if necessary. The black steel is of course cheaper but adding future outlets would be difficult. It's also not as clean as copper. The specialty aluminum stuff sounds good but I'm a little concerned about the plastic fittings and cost. Any suggestions or advice would be appreciated.

[Bill Adamsen]

Steve ... for the same reason you are considering copper (familiarity and flexibility) I chose to use copper for my pneumatic system. The materials were not particularly expensive in total (I had quite a bit of used pipe and new and used connectors) and my familiarity, and locally available materials made fast work of it. I liked that it was rated for the pressures I sought to use. The system is designed to gravity drain any condensation buildup. No complaints.

[Malcolm McLeod]

A loop or ring is very common in industrial settings, but of course will use more material. If you decide to go this route, consider 'up-sizing' the loop pipe. It is surprising the amount of air storage you can get in this volume of pipe and it reduces cycling on the compressor. However, the biggest justification for the loop is that it helps balance air flow to multiple users around the loop. This may be of little consequence in your usage plans.

As for materials, if you plan well, the black iron pipe should be easy to expand or change. I'd run the loop around the barn up high on the walls (just below ceiling), install a tee at every drop you wish to install, as well as at every potential 'growth spot', or even use tees instead of pipe couplings. Point the tees down the wall. For those you aren't using, put a plug in the tee.

At the tees you want to use now, drop a pipe leg down the wall and terminate it as you see fit - - put another tee to branch horizontally to FRLs, tools, or other points of use. Put a drip leg on the 'run' of this tee with a small valve to drain condensate.

Never used copper (for air) or the aluminum, so (I ) will stay away from (offering opinions on) that.... Hope the rest is some help.

[Sam Layton]

Hi Steve,

I used copper in my shop. I do not have experience with black pipe, nor the aluminum pipe. This is my second shop that I have used copper. I have had very good experience with it in both shops.

Sam

[Steve Mathews]

I forgot to ask about sizing. Based on the 200 ft. loop and only one person using the shop, what size piping should I use?

[Malcolm McLeod]

I forgot to ask about sizing. Based on the 200 ft. loop and only one person using the shop, what size piping should I use?

What are your points of use? What CFM is recommended/required by tools? What compressor? For what I do (tires, small stain/paint sprayer, nailers), 1/4" is plenty. On the other hand, if you have a tire changer 200' from the compressor .... well, as the preacher said, "Organist, play some check writin' music!"

Edit: This is handy and simple look at pipe sizing. It assumes you want the full volume & pressure capacity of your compressor delivered to point of use. You could figure the 2 worst cases: 1) longest run to a particular use point (with volume & pressure at that point) ; and, 2) run to the largest volume use point.

[Steve Mathews]

Malcolm - Good point. The compressor I currently have is just 5 hp with a vertical 60 gal. tank. I don't know the CFM. I don't have many pneumatic tools but can see using a paint/stain sprayer, impact wrenches, brad/nail guns and nozzles to blow off stuff. No sand blasting, tire changers, etc. The point of use could be anywhere on the loop. Copper can get really expensive when you reach 1" so I would like to keep it below that.

Edit: CFM rating on the compressor is 12.4 at 90 psi.

[Steve Mathews]

Malcolm - Thanks for the link to the pipe sizer. Based on that it looks like 3/4" is more than sufficient. It doesn't mention what friction loss coefficient is used in the charts but copper would be the better case scenario. I'm leaning toward 3/4" copper at the moment.

[John K Jordan]

Black iron pipe can rust inside and contaminate things. Copper is great.

I installed RapidAir flexible plastic pipe and fittings in the walls and ceilings. I installed eight outlets with quick connect fittings in the wood shop, machining area, little weld shop, maintenance bays, and outside. No leaks in two years of use. Ain't gonna rust. Runs impact drivers and random orbital sander, my biggest air suckers, and everything else I've used. 5hp 60 gal Ingersol compressor.

JKJ

[Steven Hosler]

Steve,

It sounds like I have a setup similar to yours. I ran 3/4" copper pipe for the loop, and then 1/2" for the drops. I choose copper for the same reasons listed above, but also because any water in the system can rust out a black pipe system over time (also risks of rust flakes in sprayers). I have also noted (as Malcolm stated), that this system seems to expand my air capacity more than I expected.

Good luck

[Brian Henderson]

I had 3/4 copper in my old shop and it worked just fine. I'll use that in my new shop, once I get around to building the shed for my compressor and dust collector in the spring. I do end up using two 1/2" 50' air reels that reach pretty much anywhere in the shop, plus a couple of dedicated drops, such as at my main workbench and in my finishing room. I put one reel at each end of my shop and I have never found anything I couldn't reach.

[Bob Wingard]

I too ran a giant loop of copper completely around the perimeter of my shop. It is a few feet in from the stud cavities, so I can get to it if/when necessary. The entire loop is gently sloped toward one corner for condensate drainage. Each takeoff starts with a "t", a 90deg. fitting and a short stub of vertical pipe ... then, a 2' or so horizontal pipe to get just over the stud cavity, and finally, the drop actually down & into the stud cavity. I have 10' ceilings, and the drops are all about 5' from the ceiling. Once inside the stud cavity and down the 5', I installed a "t" fitting and ran the piping horizontally to whatever the next obstruction might be. This large inverted "t" runs completely around the shop at about 5' from the floor. If I ever need to add on to the plumbing, I just have to remove a piece of paneling (Hardiboard in my case) ... make the required changes ... replace the paneling and cutting any necessary holes in it. I basically have compressed air available for the full perimeter of the shop, and it is not very difficult to access it. Also, there are three hose reels mounted at the ceiling, and one fitting mounted on the outside wall so I have air to inflate a tire without having to even go into the shop.

[Robert Delhommer Sr]

Just wondering if PEX piping would work? Not expensive but I have no idea what the pressure ratings, ect. are.

[Jim Becker]

Just wondering if PEX piping would work? Not expensive but I have no idea what the pressure ratings, ect. are.

I've been wondering the same thing lately as I recently used PEX for a plumbing repair in the house. I have not had time to research that, however.

That said, my air lines are all copper with the exception of a short flexible loop between the compressor and the system for sound and vibration isolation.

[Malcolm McLeod]

I've been wondering the same thing lately as I recently used PEX for a plumbing repair in the house. I have not had time to research that, however.

That said, my air lines are all copper with the exception of a short flexible loop between the compressor and the system for sound and vibration isolation.

Somebody has-been-there-wondered-that: http://www.sawmillcreek.org/showthre...-for-air-lines