Advice On Plumbing in Compressed Air Line

[lilranch2001]

I have had issues with using black iron threaded pipe years ago but it was in the building codes a long time ago.....the issue I had was the condensation of compressed air was making rust inside the pipe......resulting in rust fragments coming out ruining air tools if they were not filtered and oilers installed

I can't say I've had any PVC or plastic pipe in my shop but I'd wonder if there was a fire wouldn't the pipe melt from the heat and explode?? and fan the flames right where you don't want them??

I use copper (the heavier type-L) anchored properly with drop legs in the entire shop except for a piece of hyd hose (not regular air hose) from air comp to the wall (to reduce vibration) and have always been happy with the results....... and it looks very professional looking for the local authorities and insurance inspections......and the condensation (no rust) doesn't bother the air-tools and blow-guns

I realize using plastics will work but I can't take the gamble if there is even a slight chance of catastrophic failure......I wouldn't want to work for an employer that would cut corners like that so why would I take short-cuts and expose others to those potential hazards

:2cents:

I am going to go on a limb, and make the statement that 90+% of compressed air lines in American industry is black pipe
You should not use galvanized, as the zinc tends to flake off, copper is prohibatively expensive, PVC, well I am not needing to comment on that any more.

Back when I was doing pipe fitting for a living, all the compressed air I put in was either cut n threaded or welded sch 40 pipe.
In the last year, I have had two new compressed air systems installed in 2 different buildings and a new trunk line ran, all by different contractors and they all used sch 10 black "sprinkler pipe" with vitaulic fittings. It looks like that is the new standard.

 

[wdchyd]

I'm sure the new compressed air systems in industrial buildings have air driers to prevent condensation so using black pipe shouldn't really be an issue for them

Back in the late 70's a large local industrial plant (GTE Sylvania) had manifolds running throughout the plant.....all copper (typeL) but all silver soldered the connections instead of 50/50 solder.......their reasoning was the silver solder was for higher heat protection in case of fire

those manifolds were all copper piping running all the necessary gasses and water, IIRC they were hp air, nitrogen, natural gas, argon, oxygen, water ect

I'm thinking threaded connections (or victaulic) are best preferred for large dia's and by the fire depts for safety......maybe not...

I just don't like the rust issues with the BI for me

 

[lilranch2001]

I'm sure the new compressed air systems in industrial buildings have air driers to prevent condensation so using black pipe shouldn't really be an issue for them

Back in the late 70's a large local industrial plant (GTE Sylvania) had manifolds running throughout the plant.....all copper (typeL) but all silver soldered the connections instead of 50/50 solder.......their reasoning was the silver solder was for higher heat protection in case of fire

those manifolds were all copper piping running all the necessary gasses and water, IIRC they were hp air, nitrogen, natural gas, argon, oxygen, water ect

I'm thinking threaded connections (or victaulic) are best preferred for large dia's and by the fire depts for safety......maybe not...

I just don't like the rust issues with the BI for me

You are correct, most do have air dryers, but anymore most are refrigerated air dryers, rather than desicant, and the refrigerated dryers are only good to a 32 degree F dew point, so some moisture still make it through.

Most if not all air tool data sheets will require a filter ahead of their tool

 

[wdchyd]

Most if not all air tool data sheets will require a filter ahead of their tool

Yea, they would do that for protection on their warranty status
Problem is: how many homeowners and farms and small shops actually have filters on their small compressor
That's the beauty of copper.....water just passes through the pipe and tools....(if the drop legs miss it).....and no pressure drop from filter

 

[adjusterr]

adjusterr what size pipe did you use?

One should never show their ignorance this quickly but I'm not sure, it appears to be standard water pipe size. It's late at night but tomorrow I will measure the pipe and get back to you.

 

[Raindem]

I am ready to plumb in my compressed air line in my shop. I want something fast and cheap . Have any of you tried these people? Compressed Air Piping | Compressed Air Systems | Do It Yourself Compressed Air Systems Do you have any other suggestions for me. thanks a lot.

To the OP, yes I have the Airnet rigid aluminum piping system from these guys. It was quick and easy to install, looks proffessional, and works great. I am very happy with it. But it's not cheap. They do sell a cheap flexible line kit but I can't comment on the quality.

 

[KWentling]

Has anybody here EVER seen a PVC air line rupture? I have had it in my home shop for over 15 years inside/outside with a 10HP compressor that is on 24/7. I've heard all the horror stories but I have seen it in several shops and never heard of it blowing. Naturally you don't take the hard pipe straight to the compressor head, use a flex line.

I have seen copper air and LP lines crack from vibration and impact.

I've ran commercial shops and we have always used black pipe or the special green PVC.

Happened in the machine shop I work at. The old shop has black pipe. A new addition had a small amount of 1" PVC run on the surface about 8' off the floor. The spot where it broke was directly over a man door. Fortunately it broke on night shift when no one was working in that area. There were shards of PVC pipe thrown about 100'. I was there. Didn't actually see it happen, but sure heard it. The shop has NO PVC air lines after that. If I ever get around to plumbing air in my shop, it will absolutely NOT be PVC. I'm guessing that PVC was 6 or 8 years old at the time. Being over the door I suppose it may have been hit with something and damaged. If you have PVC pipe in your shop or garage, you have a dangerous situation. May never break, or it may break tomorrow and kill someone. I'd get it out of there or get it covered up.

Kim

 

[sparc]

You also may want to look at your liability policy, as the carrier may or may not cover an issue with PVC piping in a compressed air system.
It truly is every bit dangerous as some of the posters have commented.

I have done a few half a**ed things in my life to save a buck, but one of the last things I would do is to pipe compressed air in DWV PVC.

At least use the compressed air rated PVC, and then even then, I think you would be foolish
just my :2cents: worth

i dont belive there is such a thing as pvc that is approved , or rated as you call it, for compressed air service. Go to charlotte's web site and find anything that oks using pvc for compressed air, i bet you can't.

 

[KennyG]

i dont belive there is such a thing as pvc that is approved , or rated as you call it, for compressed air service. Go to charlotte's web site and find anything that oks using pvc for compressed air, i bet you can't.

You are correct. All PVC is brittle. The only plastic I'm aware of that is appropriate for compressed gas is HDPE (High Density Polyethylene). It does not get brittle. When it fails, it cracks or tears, not shatters. It's a great product, but I don't think it would be much cheaper than steel.

 

[lilranch2001]

i dont belive there is such a thing as pvc that is approved , or rated as you call it, for compressed air service. Go to charlotte's web site and find anything that oks using pvc for compressed air, i bet you can't.

There used to be, I had sales brochure on it years ago, decided I didnt wanna mess with it.