black pipe

[wannabedivin]

I got a gas leak in my furnace.  It is on the second to the last elbow before the black pipe actually connects to the furnace.  My question is can this be replaced with a flexible or does it have to stay black pipe.

[WoodworkerTom]

In Chicago furnaces, boilers and HWH need to be piped with black pipe.  Flex is not allowed.

[p_toad]

Is the elbow damaged or just leaking at the threads?   If it's not physically damaged, i would take it out, clean all the threads (inside and out) and re-seal with pipe joint compound (not all that fond of yellow teflon for gas)...  and then put it all back together.   You may end up taking apart more than you want in order to get that corner out.   It's just part of the joy of working with that stuff.


There should be a shut-off valve and between that and the furnace, you should have one of these...see attachment...  i don't have this all figured out yet...grrrrr


They make these connectors so that you don't have to dismantle the house to work on your piping.  they come in black iron and galvanized...this is just easier to see.   The octo connector nut lets you take the short section of pipe apart to work on it.   If you don't have one, curse the person who put it in.

THIS PICTURE IS JUST TO ILLUSTRATE THE CONNECTOR WHICH SHOULD BE THERE. THIS IS NOT BLACK IRON PIPE.

[blackhat]

Why not shut down, strip back, redope and reassemble?

[who]

Fittings are cheap... Why not replace before you spin it all back together.  Seen a few cracked fittings over the years.  Might be a possible cause of your leak if the original installer went a little too tight.

[Snipe Hunter]

I'm a licensed home inspector. I'm not a plumber nor do I quote or report on or refer to "code" in any way. That's what engineers and building inspectors do. All I do is report what I observe and I have a list of things I'm compelled to report having to do with "safety" and "standards of practice" pertaining to home construction.

That being said:

I am compelled to report anything other than black pipe in a gas line. My recommendation would be to:  to "contact a licensed plumber for inspection and repair if necessary" if I saw something other than black pipe in this application.

[daddo]

The code here is black pipe must exit the furnace, then a flex and external gas ***** can be installed to the existing pipe supply line to the furnace, unless it is outdoors or in traffic areas. Otherwise it must be hard piped.

Your codes may be very different.

[wannabedivin]

Thanks all for the advice. The furnace was installed 18 years ago.  I have the clearance so will just go with the Black pipe.  It appears it is leaking at the seam but will probably just replace it all:  Two elbows. one tee, one 8inch and a one 1 inch straight piece

[p_toad]

There should also be a drip leg off a T...

[daddo]

Lpg or natural gas?

Be sure and use only black pipe and black fittings- not galvanized with black.
Rectorseal #5 or yellow tape. Preferably Rectorseal.