I wondered about the Ts pointing up, but it made sense
later. Don't want water to rust and corrode the threads for
the plugs.

When I did a bit of pipe fitting, my old boss used to use
teflon tape, plus yellow Rectorseal #5 on the exterior /
male threads. That combination seemed to do good.

A union or two in the system makes it easier to take apart.
In theory, the unions mating surface doesn't need
Rectorseal, but the threads to the black iron do need teflon
and rectorseal.

I'd think it would make sense to spray paint the air pipe,
so it's different color than the other utilities. Water is
blue, natural gas is yellow. Fire protection is red. So,
what's that leave?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Bruce L. Bergman (munged human readable)"
wrote in message
...

If you can afford PVC Pipe and fittings, you can afford
cheap imported
Black Iron (really steel) pipe - they sell a lot of it for
natural gas
lines. Take the time to do it right, or don't bother and
get lots of
hoses.

They have the plastic coated rust resistant stuff too if you
need to
bury an air feed between the garage and house - coat the
fitting with
sealant, then wrap the fittings in the special tape and
slather
another coat of sealant over the tape to keep the water out.

Do Not use Galvanized pipe, the zinc flakes off and gets
into the
tools and valves.

And your 'Wrap chicken wire around the PVC " plan is doomed
for
failure - there is a LOT of captive energy there...

Run the riser up to the rafters from the compressor and
refrigerated
dryer or aftercooler, then when it changes to horizontal to
head off
into the shop leave a slight downhill - maybe 1/4" per 10'
to the far
end of the room - where you put an elbow and a drain leg
down to a
drain valve you can reach. Drain it every few weeks -
you'll be
shocked how much water coalesces out in the lines.

Do NOT buy lots of couplings - buy mostly Tees and Plugs,
and put a
tee every length of pipe with the third hole POINTED UP to
the roof -
when you realize you need a new drop there, you just pull
the threaded
pipe plug out of the tee and go.

If you plan to wait 20 years and then add a new drop by
cutting the
Black pipe and threading it for a new tee, FUHGEDDABOUDIT.
You'll
either snap off an old fitting, or twist the old connections
and
create a dozen leaks... And eventually between the hissing
leaks and
compressor cycling every fifteen minutes it will drive you
mad, and
you have to take The Whole Damn System Apart and start over.

The tap legs go UP from the main line for a few inches so if
there is
any moisture in the air you leave it trapped in the main
line - and
eventually it'll work it's way to that drain leg at the far
end. Then
you go horizontal over to the wall, and drop down to your
drop
fittings.

Oh, and put another tee there with another butterfly drain
valve on
the drip-leg, so if any water gets that far it's stopped
again. Water
in your air is bad news.

If you have the money you use Copper pipe - but you build it
the exact
same way with the drip legs everywhere, and up-legs to leave
the water
behind. Except you can skip the tees, it's easy enough to
cut in one
and solder or braze the tap tee as needed. (No threading in
place.)

I use Silver Braze on Copper for Air (or refrigerant) - that
way your
Plumber doesn't think it's a Water line he can tap into.
Which can
get exciting.

-- Bruce --