I......need.........air...

[mxtras]

What's the consensus for plumbing a commercial shop?

Copper? Galvanized? Black Iron? What are the pros and cons? Any advice?

PVC is a no-go, by the way (OSHA).

Scott

[ger21]

Our shop has a plastic similar to PVC that is OSHA approved. Not sure what it's called, but it's blue.

[psychomill]

All copper here....

[2muchstuff]

If you want to do it to "code" then you must use an L or M hardness of copper tube. Not the stuff you get at Home Depot that is used for water, you can find it at a plumbing supply house. You have to use a silver bearing brazing rod on all the joints. To get things up to the temp. that silver braze will flow you will need an acetylene/ air torch.

[Bubba]

Mine is black iron, but be sure you have some sort of filter at your outlet. After a few years, you will get some rusting in the lines. Where I work, it was so bad that it plugged up a regulator. Put a small filter on it and it filled it up in about a minute!

Copper won't rust and it might even give you a little cooling on the way.

As for galvanized, I haven't found a good use for it yet. If the galvenizing doesn't flake off, it will still rust after time especially at the joints.

my .02

[DieGuy]

http://www.ipexinc.com/Content/EN_CA...ressed_air.asp

The approval letter.
http://torque1st.clubfte.com/OSHA_PVC_Pipe.htm

[ChrisJ]

I would go with copper.

As Bubba indicated, copper will give off the heat of the compressed air, although I am not sure if this matters for what the air is being used for (tool, etc.).
PVC is out mainly because compressed air can easily exceed 200F and the temperature limit of PVC is 140F. It will turn to spaghetti if exposed to temperatures above 140F. CPVC is out also, it can handle 180F maximum.
Doing a little browsing on the web it appears that ANSI/ASME (B31.8) limit the use of PVC, or other thermoplastics, for transporting compressed gases.

The blue stuff refered to by Gerry may be polypropylene, not 100% sure. Even this has a temperature limit that isn't much more than 200F.

Soldering the copper should be just fine unless you plan on very high pressures. You may want to refer to a temp-pressure chart that will indicate what the limit is for soldered copper fittings. I have one filed away somewhere. Soldered copper should be good for 125 PSI at least.

If you braze the copper fittings you will be golden, since this will handle pretty much any pressure that a compressed air system can throw at it.
Copper type M, L should be just fine. Since compressed air will not corrode or errode the interior wall, M will do just fine. L buys you some extra wall thickness that isn't really needed for air applications, unless of course you will be banging things into the copper tube, then the extra wall thickness will be a little more resilient to being bent or crushed.
In all the Lab projects I have been involved with (day job) type L copper is what we specify. I am not sure what copper tubing 2muchstuff is refering to. The tubing at Home Depot should be the same as a supply house for water or air, but I could be wrong. I know there is ARI rated refrigerant copper tubing, but that is the only other copper tubing I know of.
The other benefit of copper with brazed or soldered joints, over threaded steel, is that these joints are easier to make air tight.

Just my $0.02.
Chris

[ger21]

That's it. The Duraplus is what we have.

[sol]

Just a for what it is worth.
Type K copper is the thickest walled and is what is put in concrete floors for residential water lines.
L is next and M is the thinnest.
I am not fond of M, after working with the other two it seems flimsy; it is primarily what Lowes and Home Depot sell though sometimes they have L as well.
They are frequently mixed up in the store's racks...
Check for the color code: K is green, L is blue and M is red; the inspector sure will.

Oh yes, and I use black pipe, it can take a serious bump, but yeah, like Bubba said, it rusts.

[ChrisJ]

That Duraplus is rated at 185 PSI at 73F. What is the pressure rating of the pipe at 200F? The air leaving the compressor when you compress the air to 100 PSI or better is going to be hot.
Did they use the Duraplus on the distribution only, and used something else close to the source?

Sorry there Dieguy, you already had the link attached would referenced the ANSI/ASME standard. I should have looked at your links first.

Chris

[Ken_Shea]

As for galvanized, I haven't found a good use for it yet.

LOL

The truth and the whole truth so help me experience

[mxtras]

I have seen the blue plastic stuff installed in a plant in Canada and I know it is OSHA and locally accepted, but it looks expensive for some reason....and I have only heard or seen it used maybe two times in the last three years, so I am a bit sceptical. If it was the greatest thing, it would be used more frequently, don't you think? There has to be a reason or two it's not more popular.

Any rough comparisons in price and ease of installation when compared to, say, copper?

Scott