Mix & Match Gas Pipe

What are some of the problems associated with using black iron and galvanized pipe together for natural gas? THANKS!!!

Buck, you might want to check with various AHJs in your area and see what they say. Some will allow it, and some won’t. Some will allow just a little bit of galvanized pipe.

Mostly, it’s up to the Power Compnay to set the rules.

Galvanized pipe is commonly used for water systems, black pipe for manufactured and natural gas.

I’ve never heard of galvanized piping for gas usage. As far as I know, Galvanized pipe should never be used for gas installations.

I agree not allowed in Canada either.
Roy Cooke

Most jurisdictions do not allow galvanized because of the possibility of the zinc coating flaking off inside the pipe, and clogging orifices and valves.

down here all you see is galvanized, took a little getting used to after run black pipe for 14 years. That and the lack of a drip leg, or flex lines though the unit casing. Don’t get me started.:smiley:

One of the other reasons that galvanized pipe is not normally acceptable and the gas pipes are black is so that once someone removed the pipes they are not used for water lines.

Galvanized pipe is porous and absorbs gas. If later used for water lines, the water will be poisoned by the gas in the piping.

Galvanized pipe is also not made to the standards of the black pipe. The galvanized pipe has flaws in it that are not acceptable in the black pipe. The gas is a smaller molecule then the water. Small leaks are a bigger problem with gas.

\ This web site also says never use Glavanized for Gas

http://www.acehardware.com/sm-learn-about-pipes-fittings-and-valves–bg-1267591.html

Galvanized pipe is commonly used for water systems, black pipe for manufactured and natural gas.
Galvanized pipe should never be used for gas installations.
Plumbing codes in many areas require that black pipe, especially that used underground, be coated and wrapped.

Roy Cooke

I’ve talked to the Ohio Gas service techs. in this area and they say O.K. to use either. Ill just keep using black myself.

"Buck, you might want to check with various AHJs in your area and see what they say. Some will allow it, and some won’t. Some will allow just a little bit of galvanized pipe.

Mostly, it’s up to the Power Compnay to set the rules."

(Seems to me I just read that somewhere.)

You wouldn’t want to condemn it in a report if it is allowed — or visa-versa…

Although it is not against UPC to use galvanized pipe for gaslines, there is a problem with connecting dissimilar metals. Electrolisis will occur anytime that you mix metals without using a dielectric union. Granted it won’t happen as fast with a gas line as a water line, but it will happen.

Our gas/electric power company in eastern North Dakota (Excel Energy)will not allow galvanized pipe for their natural gas either. We just put in a gas heater and we know.

George Maher
Home - Safe Home, LLC
Fargo, ND

Galv and black iron are not dissimilar - they are both steel.

I’m surprised to hear so many say it’s not allowed. There may be some local ordinances that prohibit it, but the model codes allow it. I see it quite often.

UPC 1210.1 Allows galv steel for gas piping.

IRC G2414.4.2 Allows it as well.

You won’t find it in Massachusetts.

Massa whozits?

Well if I can’t spell it, I ain’t goin’ there :wink:

I have worked on tons of gas lines that have had some galvanized iron pipe installed and have never noticed any flaking of the galvanized within the pipe.

Galvanized pipe is not normally allowed in this state. Plumbers and gas fitter licensed HVAC contractors do not use any thing but black iron. When ever I notice galvanized pipe this tells me that the homeowner has been doing his own plumbing not knowing the difference.

As an inspector I do not write up a few nipples or elbows installed in the system usually just prior to a gas control valve, but if the complete line was galvanized I would have it in the report.

I have to agree with Jeff Pope galvanized iron and black iron are not dissimilar metals