Compressed air in the shop...

[Jim Sherman]

I am planning on running air from one end of my shop to the other, black iron pipe no pvc! the run will be 80' or so, any thoughts on the size of line to run? is 1/2" too small? it will be for normal shop air, nothing too big. Running it off an antique 50 gallon tank & compressor setup.

Thanks,
Jim

[JKWidener]

Anything over 30ft, i have always used 3/4 inch. Our shop at work has a run of about 80ft and they used 3/4 inch.

[Craig A]

Agreed........go with the 3/4" pipe or you'll be sorry........and short of air........

PROPS for using black pipe!.......

Do yourself a favor and put drops with drains below your outlets so you can drain condensate every now and then......especially where YOU are.......

[Rod Fielder]

Never black pipe. Galvanized only. Black pipe will rust inside in a hurry. The bigger the better for storage . 1" min.

[Eric M.]

If ya really want to be classy, use copper.
Note: Not responsible for drained bank account

[ken karrow]

I did mine with 1/2" REFRIGERATION grade soft copper. Ran about 50' total. Never regreted it, copper will not corrode in my life time and is used at 300 + psi. I don't know the rated pressure but the high side on an AC runs 300 to 325 psi on a hot day in Texas, safety shut off is usually 400 to 450 psi. Use brass fittings to pipe thread at the ends. Suggest flare fittings but compression will work if you do not have a flare block. May be a good time to suggest a flare block to CFO. Copper is easier to work with too, but I may be biased, have done refrigeration since '66. Good luck with your project. Don't forget to put an outlet w/quick disconnect at the door. Then you can use air outside without leaving the door open for the hose. Ken

[CaseyJoeS.]

Black iron is code for compressed air and steam etc. though isent it?

[Jim Conte]

Originally Posted by Jim Sherman

...Running it off an antique 50 gallon tank...

My neighbor's young daughter lost her leg when a 20 year old 10 gallon air tank ruptured...

IMHO, nix, nix on the antique, unless Ultrasonic Thicknes tested, especially along the bottom where condensate laid over the years, and rusted the steel. Don't forget to have a working relief valve to protect the tank if the compressor doesn't shut off.

[Jim Sherman]

It's been hydro tested and has a good working relief & shut-off.....

[Jim Sherman]

Originally Posted by Craig A

Agreed........go with the 3/4" pipe or you'll be sorry........and short of air........

PROPS for using black pipe!.......

Do yourself a favor and put drops with drains below your outlets so you can drain condensate every now and then......especially where YOU are.......

I was "within range" when someone (NOT ME!) was pressure testing a PVC system with air instead of water... that was 17 or 18 years ago and it completely cured me of ever wanting to see compressed air in PVC. It went off like a bomb and sent plastic shrapnel everywhere....

[Andrew Mackey]

My son works in a shop that has a 2" PVC air supply piping system. The line blew a Tee and several feet of piping apart yestarday, scared the tar out of everyone in the shop, and sent fragments 60' thru the shop! Luckily no one was hurt.

I used 3/4 type K soft copper tubing, with silver soldered connections in my garage. No worries about rust, easily mounted, don't have to worry about spinning fittings down stream of where you are adding connections. Able to take impacts without breaking fittings, and will hold over 300 PSI or more. This copper is used for oxygen supply @250 PSI, Nitrogen @150 PSI and compressed air #250 PSI, in local hospitals. If you solder the fittings with regular solder, use a lead free solder like Canfield, and wrot copper fittings. It has 4% silver in it, and chemically bonds with the copper pipe and fittings. in a fire , the solder turns granular, and you cannot seperate the joints. Your only recourse is to cut the fittings out! I have tested these regular solder joints to 250 PSI without joint failure. Most compressed air systems do not exceed 120 pSI, more than 1/2 the test pressure I did.

Andrew

[diesciple]

I would recommend you run that in 1". In the UK we have an aluminium compressed air pipe product. It is a complete system with specific fittings , clamps etc. Accepted and passed for compressed air and insurance company approved.
We also have plastic , but polypropylene not PVC. Also approved for compressed air systems. Installations can still be made in steel but galv not black. Although having seen the inside of a galv steel system after only 5 years of use I would never use it.