On Sun, 10 May 2009 12:15:30 -0700 (PDT), engineman
wrote:

I have a gas line running to my outdoor hot tub water heater. When I
first installed it 8 years ago I used black iron pipe because i heard
that it was required.
Lately I've noticed that it is heavily rusted where it is lying on the
concrete.
Can I replace it with galvanized?
I get all sorts of answers from google.
Engineman

Get it off the ground, clean it up, prime and paint it. Problem
solved.

If you hear whistling from the gas pipes when the hot tub heater
kicks on, do the CFM flow math. You might need to take it out and
bump the pipe up a notch or two (1/2" up to 3/4" or 1") - and prime
and paint it well as you replace it.

You don't want to use galvanized unless you really have to. Plumbers
see galvanized pipe and they think "water"...

If it is buried, the pipe is supposed to be the green plastic coated
black pipe, and you have to wrap all the joints and couplings with
approved tape to seal out moisture and reduce rust. But this is above
ground.

-- Bruce --