air lines

[antone61]

I am running compressed air through my shop. What is a cheap pipe to use? Do they make a pvp pipe for this?

Thanks Antone61

[foureyedbuzzard]

Best performance / cost compromise will be copper pipe(K or L) with soldered fittings. Black iron more durable but tougher and more costly install + has condensation/rust problems down the road. Remember not to go too cheap - use some unions so you can easily repair the system - and enough shut-off valves for OSHA lock out points as required.

PVC was banned for compressed air service by Dept. of Labor back in early '90's - don't know if ban recinded since then. Too much of a chance (impact breakage) around tools, fuel/solvents(softening), and auto's anyway.

[antone61]

Thank you very much. This is a do it yourself job and I can solder. It is for my shop out back and I only run 110 psi.

[foureyedbuzzard]

You're welcome. "L" copper should be fine. Remember to size your main air header large enough to supply all the tools you may be running at the same time - and go 3/4" or 1" MINIMUM header to 1/2" taps. Even in a small shop, a 1/2" pipe many times won't keep up with two air tools running at the same time.

Just some links on why NOT to use PVC for compressed air piping. (You got me thinking...) ABS, however, can be used provided the pipe is marked approved for such use by the manufacturer. I'd shy away from plastics in above grade installations, if for no other reason the possibility of physical damage.
http://torque1st.clubfte.com/OSHA_PVC_Pipe.htm
http://www.osha.gov/dts/hib/hib_data/hib19880520.html

[antone61]

Should I put a filter/oiler at the end of each tap or is one at the compressor end enough?

[foureyedbuzzard]

You don't want oil, or water - or anything but air in your main air system - think of just using a blow gun to dry off a washed part or blowing down the drill press or better yet - painting! A coalescing/filter regulator at the beginning of the system should be adequate to knock out some of the moisture. Set up your oilers on quick connects, figure a way to keep them level(a proper size pipe/conduit clamp on the wall works), that way you'll only need one or two and can use them at the tap location and tools you need them at.

[coop7295]

Ive set up several shops you not use copper pipe according to most state and city officials let alone copper pipe is only good for pressures around 70-100 psi. Black pipe is whats used most of the time.

[foureyedbuzzard]

Originally Posted by coop7295

Ive set up several shops you not use copper pipe according to most state and city officials let alone copper pipe is only good for pressures around 70-100 psi. Black pipe is whats used most of the time.

1)Steel pipe("black iron") would be overkill for a home shop. Copper is acceptable in almost all jurisdictions for commercial and industrial use with most non-flammable compressed gasses. Black iron may be required in certain areas for impact resistance and to meet certain specific fire code situations - but it is never the pipe material of choice, due to inherent corrosion and scaling problems.

2)The pressure rating of the system is dependent upon the pipe size and type of joints used. Copper pipe itself is quite strong, with true burst pressures measured in THOUSANDS of pounds! The method of joining is the weakest link, with sweat soldering being the weakest. Almost all "shop air" pressures fall well under the working pressures of sweat soldered systems. http://64.90.169.191/applications/pl...cth_table4.htm
The Rated Internal Working Pressures for type K and L copper are well over 300psi in 2" and smaller diameter at normal ambient temperatures.
http://64.90.169.191/applications/pl...sign_burst.htm