Well since I am in the pipeline welding business and deal a lot with
undergound pipe I have to comment... First of all you have to consider
legalities of where and what your burying in gas pipe....some places won't
allow you to bury gas lines in steel nowadays.....underground threaded
connections in steel are also a "no no" in some areas....nowadays they use
plastic to bury gas pipe......after looking into that.......This is to
answer your question..

If your going to use steel then you should go black pipe ....Galvanized
pipe will break down with gas so don't use it (galvanized steel pipe is
mainly used with water)....then coat the black pipe with tar and then tape
over the tared pipe with plastic tape to seal the pipe from exterior
moisture. If you must use fittings underground, It's best after tarring the
**** out of the joint, to use heat shrink wrap type sleeves over the tar and
fitting for a good seal against moisture.....

Again...for your sake and your neighbours, please go
plastic pipe for underground use...The joints should be "fused"....not
threaded or Flanged together for underground use...

I just hope I didn't give help to someone that is running an
underground grow operation or anything................Jimi



"Smarty" wrote in message
...
Is there a "best" way to install underground gas pipe? Is black pipe
preferred to galvanized or vice versa? Should fittings and possibly pipe
be covered with some coating like an epoxy paint or silicone caulk or some
other coating? Any other hints?

Thanks very much.