On Wed, 23 Nov 2011 08:34:42 -0500, "Stormin Mormon"
wrote:

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?
Black???
Gerry :-)}
London, Canada