Rigid Air Line Question [No Not a PVC Question]

[autoxbrian]

Decided for my application that L copper will be the means for my air distribution system in the garage, I will have approximately 40' of copper pipe, at about 20' I'll have a 50' 3/8" retractable reel, and at the end, I'll have another 50' 3/8" retractable reel.

Questions are these: Any reason I couldn't get away with 1/2" copper for the distribution, rather than 3/4" which seems to be more popular amoung some on here?

And: Are all copper fittings typically of a thickness of L copper as well (to handle pressure up to 150-200psi? (normally will run at 90, but want a safety margin).

The compressor can put out approx 18cfm @ 90psi, max pressure of 165, 60 gallon. This is for home occasional use application, impact, cut off wheels, grinder now and then. No blast cabinet (though if I have one in the future it will be placed close to the compressor) and rarely if ever have I had two air tools running. So I understand that there may be a small reduction IF multiple users were to ever try to utilize the system, but with that being a highly rare occurance... It seems that 1/2" will not be a hinderence to overall performance, and definitely is kinder on the pocketbook.

 

[autoxbrian]

Sure thought I'd have some comment(s) on this.

 

[Mike F]

You are only talking 40 ' of pipe and some fittings. Though you may not need it now (or perhaps even in the future), it is better IMHO to go with the 3/4". " It is better to have and not need, than to need and not have". It should not be much of a price difference.

 

[autoxbrian]

Thanks Mike, point taken.

I guess that is where my question lies, how will the 1/2" ever leave me in 'need'? I don't need the volume of air in the pipe, nor do I think that 1/2" will hinder the cfm flow for my more intermittent, single user use. Without seeing/finding a resource or chart showing cfm limits by pipe material/diameter, I guess I'd be hesitant to spend extra money on 3/4" if there is just a preceived benefit for my intended use, not actual.

I did see a copper manual mentioning over 75' of pipe length should go to 3/4" (for air flow/loss reasons) but I can't seem to find it again, and I will not be over that in rigid pipe.