I was always told that black iron pipe
joints are "tighter" because the threads
grind
into one another and that this doesn't
happen in galvanized pipe. Black iron was
supposed to be "softer" whatever that
means. As I said, this is what I heard.
I really
never believed/understood it..

Greg O wrote:
"Calvin Henry-Cotnam" wrote in message
news:Q2rgf.1849$hW.463@tor-nn1...

Which is better for compressed air?

I would like to run a permanent line from a location where I would like
to run the compressor (for noise reasons) to another room for use.

Years ago, I used to work in a plastics molding plant and I seem to
recall that galvanized pipe was used for the compressed air lines, but
I thought I would throw the question out here to see what opinions there
are.



For what ever it's worth, I have never seen galvanized pipe for air in a
commercial/industrial application. Not saying it does not exist, but plain
black pipe is more common.
I see no reason why you can not use either. Today's galvanized pipe is much
cleaner than years ago so flaking should not be a concern.
Greg