Compressed air distribution

[metalmagpie]

My father-in-law (a retired mechanical engineer who is very savvy indeed) says why not use PEX? He says it's dead simple and makes enormously more sense than copper.

Not that I'm going to. I'm collecting (scrounging) type L copper pipe and pozi-drains for when (someday) I make my air system.

metalmagpie

[Evan]

I have installed both black iron and copper for natural gas in two different houses. I will take copper any day for a homeowner installation. I even put in a valve isolated manifold for the copper gas system and that was a piece of cake. Makes installing new appliances a lot simpler.

BTW, the gas inspector wanted to see the black iron hold 100 psi for 24 hours. I knew he would since I asked him in advance what he was going to pick on. He didn't bother inspecting the copper system.

[Stern]

Duplicate

[Stern]

True, I guess its easier for me since I have the threader to do black pipe. I found that if I used a standard dryer at the compressor I really got no scale or rust flake buildup in the pipe. Now I sure wouldn't use black pipe if oil was going to be an issue, as oil does leach from the pipe even when dry. Guess its just a preference thing with me, as I have enough black pipe lying around to build a ladder to the moon lol, and as for fittings .... well, built a 16' x 30' shed just to hold them (sure freed up garage space lol).
I think if I was going to use copper for my lines, I would braze them instead of just solder, but that's probably because I am extra cautious when it comes to pressurized anything lol.

[MichaelP]

I'll tell you my personal reasons to stay away from the black pipe. The main reason- significantly more labor intensive installation (for those who don't do it regularly) and extremely difficult later changes and additions. Besides, I didn't want to get into a situation in the future where I need to decide how to manage rust flakes occluding regulators, filters or devices directly connected to the pipes.

[Stern]

Well copper actually "rusts" (decomposes to copper salts... you know, the nice GREEN) just like most metals (we dont call it rust as we reserve rust for "iron oxide", corrosion is a better term), and while it may be slower than iron, black pipe walls are a LOT thicker. Leaving aside the fact iron is far cheaper than copper (and the GOOD copper pipe is pretty pricey, not the crappy Chinese thin wall that comes with free pin holes), black pipe is actually impregnated with oil (its what gives the sprinkler water that black oily look and distinct smell of "money" lol). While wet systems (water filled lines) last a hell of a long time, the dry pipe systems (air in the lines) last between 25 and 50+ years.

While either is fine, I prefer black pipe because its cheaper, lasts longer, and is thicker (which is important to me for anything holding "pressure"). While I have no idea of the actual pressure ratings of copper, I know black pipe can go well past 300 psi (I know this because when pressure testing a sprinkler system, the system MUST hold a pressure of at LEAST 2X the max operating pressure [usually 150 psi] for 2 hours without any incident or a pressure loss of greater than 1 psi).

[MichaelP]

Black pipe will last far longer than copper

I'd think it's vise versa. Both will work for a very long time, but copper will not rust.

[Stern]

I use 1" black pipe (since I do sprinkler work I have a lot kicking around). Pipes and fittings are rated for 225psi max working pressure, but not sure why you would want to run 175, 120 is fine for just about any application I can think of. Black pipe will last far longer than copper and is a lot cheaper, and is probably why most sprinkler systems use black pipe (except the new blazemaster plastic pipe, which is expensive and in my opinion CRAP lol).

[wbleeker]

I used polythene pipe, the high pressure stuff and have had no problems. What we get here has a blue stripe on it.
Will

[NzOldun]

design your line for ~ 100feet per sec.

NzOldun

[Toolguy]

I ran 1/2" air hose around the top of my shop (30' X 30') on 3 sides with a 1/4" drop in several places wherever needed. The compressor is a 5HP on an 80 gallon vertical tank. It's been problem free since install 14 years ago. I can run any air tool I have with no lack of supply.

[J. R. Williams]

If you are going to operate at 175psig then the standard cast black iron pipe fittings(malleable iron) are not rated for that pressure.

[Fasttrack]

Old thread...

Incidentally, I just finished installing air in my shop. I just ran rubber air hose through the whole thing. I used 3/8" air hose, which has a significant pressure drop at long lengths. I countered this by adding a receiving tank at the other end of the line. Plus, I only use the line for running brad nailers and blowing chips. The real air tools are used in the garage where the compressor is located.

So if you are contemplating running air in your shop but don't want something as expensive or permanent as running steel pipe, etc consider using air hose! Just remember that you probably won't be able to run an impact gun at the end of a 100' run of 3/8" very effectively.

[lakeside53]

He didn't say "PVC pipe"... (thank god or we'd have continued another raging thread like bar oil for ways ) - air lines on trucks...

[Evan]

This is the problem with PVC pipe.



Don't forget that expanding air gets cold.