On Sat, 16 Feb 2008 22:07:56 -0700, "Donna Ohl, Grady Volunteer
Coordinator" wrote:
snipped instructions for heater replacement

If your pipes are galvanized you don't need di-electric fittings.
My guess is special tape/dope for NG is just bull**** to sell
expensive sealers, but do what you prefer with that.
I use the same teflon tape for gas and water. As you've noted keep it
off the first couple threads so it can't get in the pipe flow.
I always look end-on to ensure that. Once inserted for tightening it
can't move forward.
Unless it's the exact same tank, you will have to use different length
nipples. Until the new tank is in place, you are guessing.
If you aren't handy with plumbing, get somebody who is to help.
If you do it alone, do it when parts are available.
You may find some of the old pipes/fittings scaled up and need
replacing. Same with stop valves. This is the time to replace old
questionable stuff.
Since I don't cut my own pipes any more, when I do a job like this I
make sure I have plenty of different sized nipples available.
They are pretty cheap, and I don't have to go back to the store.
The biggest "art" in working with steel pipe is feeling when you
should stop turning, or go for another turn on a fitting that requires
alignment. How hard you crank down a series of fittings can add
or subtract inches to a run of piping.
When working with some tight fittings, ie those connected by close
nipples, a pair of 14" channel-locks can take a bite on an opposing
fitting that a fatter pipe wrench can't. They are expensive but come
in handy for many, many uses, even removing car oil filters.
Take your time, think as you go, be especially careful with gas.
Good luck. And let us know how it worked out.

--Vic