Is it safe to use copper and galvanized pipes on the same fitting?

Also I have installed air systems for over 35 years, since the early 70's and I have seen a great many Copper systems some of them in large shops and very old and I have never seen Copper "wear out". I have seen Copper fail due to damage or from fatigue from poor support but wear out, no way in a normally operated shop! The only way that could happen is if there was some sort of abrasive being carried in the air and/or maybe heavy air flow for years and while I suppose that is possible it would have to be from a gosh awful dirty air system or if the air is clean a LOT of years of full time use!

Suggesting that Copper is a bad choice and should not be used because it will eventually wear out is simply ridiculous. There are hundreds of thousands of air systems using Copper and have been for a LONG time so where are all the complaints of Copper pipe wearing out? I don't claim to be an expert about it but I rely on the expertise of people who install this stuff for a living.

I was told copper is a no no for a safe system. If you look at the thickness of copper compared to pipe, there is no comparison. My friend only does industrial and the NEVER use coper, he says it is to easily damaged and wares out.

I don't claim to be an expert about it but I rely on the expertise of people who install this stuff for a living. I was told copper is a no no for a safe system. If you look at the thickness of copper compared to pipe, there is no comparison.

My friend only does industrial and the NEVER use coper, he says it is to easily damaged and wares out. The air piping in our research building was installed in the 60's, it is all copper. We are a major University and this system moves some air.

We use shop air to run a single cylinder 2.5L engine under boost at high load. That takes a little more air than a da sander. My guess is they are not using it in an industrial setting because copper pipe would be easier to damage, not that it wears out, unless they are pumping something else besides air.

If you ran a fork lift into a 3" copper pipe, it would be much more likely to rupture than if it was 3" steel. You can't compare industrial applications to non industrial. Once again 35 yrs experience here in plumbing .

Copper can wear out or rupture at a seam but this is very rare . Usually in both cases we are talking after years of running water 24 hrs a day 7 days a week etc. but then again I have repaired both black and galv lines which have rotted out from just a .5 psi . Installed properly both will probably outlast you and I baring any unforseen accidents.

I was told copper is a no no for a safe system. Copper is a very safe material to use and it is used in industrial settings all the time, I have installed a lot of Copper pipe in past years in large shops mostly in mine maintenance shops. The thickness of the Copper pipe is of no concern except in an impact situation and it will easily withstand pressures far in excess of what an air system is going to expose it to, I have even seen it used for hydraulic line which greatly exceeds the pressure ratings of the pipe and it still did not fail!

F you look at the thickness of copper compared to pipe, there is no comparison. True but so what? Either is a case of over-kill for air line pressures anyway and again the only disadvantage to Copper in this case is in impact resistance and that is hardly a safety hazard.

Copper pipe would be hard to rupture in a blunt impact situation as it would just tend to flatten out and maybe plug the line and even if someone did manage to knock a hole in it what of it? It is not going to rupture explosively it will simply leak and although it could be argued that an accident, such as the fork lift example, could seriously damage Copper pipe I hardly think iron or galvanized is fork lift proof. Iron pipe would certainly be stronger in a situation like that but a comparison like that is a classic case of "splitting hairs" and no system is going to be accident proof although iron might be reasonably considered for that reason in a commercial shop.

As for Copper wearing out I am still wondering about the reasoning on that one, the air is going to eventually wear holes in Copper pipe? I stand by the comment that air wearing holes in a Copper pipe system is ridiculous and is no reason to not consider Copper. Copper is the best choice for a small air system that will not have a lot of cooling surface due to short runs of pipe, it is a safe material to use, is easy to install, has been used in countless systems for many many years with no reputation for failure (just the opposite actually) and unless it is exposed to some kind of abrasive or corrosive in the air flow it will last for generations!

One more note here, All this discussion pertains to hard Copper pipe of class "M" or "L" and soft Copper should never be used anywhere on an air system with maybe the exception being the commonly used Copper pipe from the pump head on the compressor to the unloader valve which seems to be usually soft Copper but then a lot of times this line is plastic. Last edited by oldred; 09-07-2010 at 11:21 AM. Once again 35 yrs experience here in plumbing .

Copper can wear out or rupture at a seam but this is very rare . Usually in both cases we are talking after years of running water 24 hrs a day 7 days a week etc. but then again I have repaired both black and galv lines which have rotted out from just a .5 psi . Installed properly both will probably outlast you and I baring any unforseen accidents.