Galv. Fittings OK w/ Black Pipe for Gas?
| Posted in Energy, Heating & Insulation on
Peter Hemp’s plumbing book recommended it because he says that the galvanized will help seal any porosity in the cast fittings, but I though that natural gas and galv. don’t mix?
The only place I planned on using galv. would be a 12″ length of 1 inch at the building entrance from the meter. After that I was going all black iron (in a crawl space and within the walls), but I was wondering about the fittings.
Thanks!
Jim
Replies
Ask your gas utility company. The chemical content of gas varies from place to place. Here in LA, I see black pipe and galv mixed all the time. Taking apart 80 year old stuff, the insides look fine on both.
-- J.S.
Galvanized is used extensively for gas lines outside.There is no problem that I know of using black iron and galvanized together.
mike
The 'problem' with galvanized pipe is that some of the galvanizing might flake off.
I would only use it before the drip leg.
Drip legs are another thing that varies from place to place. I don't remember seeing many out here.
-- J.S.
It used to be (like 60-80 years ago) that galv pipe had a less than exceptional seal of the linear seam, meaning that it could leak gas if a piece was a sigma or two off the mean. (Or a least this is what I was told by an old gas man.) But I believe that manufacturing practices have changed since then such that there is essentially no difference between black and galv now, other than the galv coating.