On 1/22/2011 8:39 AM, wrote:
On Jan 22, 8:31 am, wrote:
wrote in message

...

Was at Lowes tonight picking up stuff for hooking up my HW heater this
weekend and found out they did not have anymore 1/2" Tee's in black
iron for my gas line. But they had galvanized 1/2" Tee's.
Can I mix the 2?

Black pipe and galvanized pipe are the same material with just one
difference: galvanized pipe is coated with zinc to prevent the underlying
steel from corroding. Galvanized piping was commonly used in pipes that
carried drinking water--before the widespread use of copper piping and PEX
tubing. Black pipe was used in drain lines, heating piping and natural gas
piping. Black pipe can be used in lieu of galvanized pipe as long as the
piping system isn't for drinking water. Since both pipes are basically the
same material, they fit together with ease.

http://www.ehow.com/how_6816090_mix-...ized-pipe.html

It's interesting that they worded it as "black pipe can be used in
lieu of
galvanized pipe...." and did not state that they are interchangeable,
ie
the other way around too. Though they seem to imply it. That
is the opposite substitution that the poster is asking about. And
like Rico
stated in the first reply, different areas have different rules
regarding the use
of galvanized pipe with gas.

I think from a practical standpoint, it's a nit. The theoretical
issue is that
natural gas can have contaminants which could react with the zinc,
form
flakes, which can come off and create problems. But, whether today's
gas even has that issue I don't know. Nor have I ever heard of it
actually
ocurring. IMO, you could mix the two if you had to, and it would be
fine,
but might not comply with local code. I'd just go find the black
fitting,
which are very common and should be easy to find.

I also think the ehow advice is incorrect in general anyway. First
they state
that the glavanizing is to prevent corrosion, then they say you can
substitute
black iron? Suppose the application is outside, exposed to the
weather,
for example. Galvanized won't rust and need to be painted, black
iron will.

The rules and inspectors in my area do not allow galvanized pipe use
on natural gas systems. I think in the uniform Southeast building code.

TDD