As a manufacturer's rep for a company that manufactures cross-linked
polyethylene (PEX) tubing (and directly sponsors my vintage racing), and as
one who is building my own shop even now, I have to respond. First and
foremost DO NOT use PVC pipe. PVC is brittle and will be reduced to
shrapnel if it fails. Metal pipe may cause some condensation of water in
the pipe as stated in the former response, although the pipe run through a
heated space won't get very cold, probably not cold enough to have much
effect on the amount of water in the air. Most of the condensation will
take place in the compressor's tank, hence the blow-down drain on the bottom
of the tank.
I'm using PEX-A pipe (there are lesser grades of PEX but I recommend pex-a)
to run my air lines. The pipe is ASTM-rated for a working pressure of 160
psi @ 70 degF, plenty adequate for most systems. Incidentally, the
manufacturer must test to 1.5 times working pressure to obtain that rating.
Our tubing's actual burst pressure is in excess of 650 psi at 70 degrees.
The tubing comes in sizes from 1/4" to 3 1/2". 1/2 or 3/4 is probably what
you'll use. I'm running all 1/2". Pex tubing can be run as a homerun
system. That is, I'm running the tubing (in my case beneath the concrete
slab) from the compressor to each drop. Since it comes in rolls up to 1,000
ft. long I only need to make a joint at each end, thus minimizing the
chances for leaks and speeding up greatly the installation process.
I'm using the same type of tubing to heat the concrete slab and consequently
the building, and to run my water lines. There is no better way to heat a
shop than to heat the floor. Low operating costs are a bonus. Warm floors
are great when you're working under a car. Your feet are always warm. But
you didn't ask about heating, did you?
I doubt that the former respondent used cast iron pipe. He probably used
wrought iron pipe. Perhaps the fittings were cast iron, but the pipe was
not. I agree that copper pipe would be easier to work with than
screw-threaded black iron.
John Lehman
'68 Triumph GT6
Ohio Regional Office
J.C. Mottinger Associates, Inc.
Manufacturers' Representatives
1008 Crook St., Grafton, OH 44044
Ph: (440) 926-2404 Fax (440 ) 926-1194
JELehman@ix.netcom.com www.Wirsbo.com
>
> << Finally got my large air compressor and would like to plumb my garage
to
> bring air to several points instead of dragging the air hose around. The
> conventional solution seems to be galvanized pipe or copper, but I've
heard
> that some people have used plastic successfully, which might be easier to
> install. I know they're not using Schedule 40 PVC or the like but is
there
> another readily available material which might be preferable?
> >>
> Call TiP (1-800-321-9260) and get their catalog. They have a complete
> description of how to properly run air lines. Metal is better than
plastic,
> because the metal lines help condense the moisture out of the air. Water
is
> death to paint and airtools. Follow their instructions on how to do
risers
> and drops in the air lines to further reduce water content.
>
> I used cast iron pipe. If I had it to do again, I'd use copper. It is a
> bitch to get all of the threaded joints not to leak air, particularly if
you
> have a dual stage compressor at 175 psi. Don't ask how many joints I had
to
> redo, and I used lots of Teflon tape. Be sure to use copper pipe capable
of
> high pressure. You can still use copper to cast iron adapters if you want
> for the drops in your shop. I also found cheap air shut off valves in teh
> Harbor Freight catalog that work great.
>
> Run the air lines near the ceiling, and put in more drops than you'll ever
> think you'll need. You'll be glad you did. You can never have enough
> airdrops, sort of like electrical outlets!
>
> Jon Lowe
> PCA Tech Committee, 914
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