Gas line materials question...

[KMorley]

I live in Tampa, Florida and have a natural gas water heater. It is plumbed using galvanized pipe through the attic to a couple of galvanized 90 elbows and a short nipple to a brass gas cock and short length of soft copper to the heater.

I thought that code prohibited or discouraged mixing materials in gas lines. For example, if a line starts out galvanized, you shouldn't mix galvanized and brass tees and elbows, etc.

Galvanized gas cocks are pretty rare in our area and brass are the norm. Also, I personally think brass unions seal better than galvanized unions.

So here's the question:

Is it acceptable to use brass gas cocks and unions in an otherwise all galvanized gas line? Again, the line I am talking about is all above ground - either in the attic or exposed on the garage wall.

I would appreciate any clarification.

Thanks!

Ken Morley

[johnjh2o]

Brass gas cocks are acceptable along with many ball valves that are stamped WOG. (water or gas)

John

[KMorley]

John:

Thanks for the quick response.

How about brass unions - are they acceptable in a galvanized gas line? Or should I use galvanized unions?

Thanks!

[phishfood]

I looked this up in the Florida Gas, as I thought I remembered unions being disallowed in gas lines. I couldn't find it, but I would still be wary of using them. They can be difficult to get a reliable seal out of. I DEFINITELY would not use them in a wall or ceiling space.

[havasu]

In California, any unions in an enclosed place (walls, attic, etc.) is prohibited but a reverse thread coupling is not.

[KMorley]

OK, so I read the Florida Fuel and Gas Code and got the answers:

1) Mixing materials:
See section 403.10.4 "Metallic Fittings".

It says that with a galvanized line you can use steel, brass, bronze or iron fittings - just about anything besides copper. With copper or brass lines you are restricted to using only brass or bronze fittings. Apparently, copper fittings are never acceptable.

There is an additional caveat:

See Section 403.4.3 "Copper and brass". Prohibits use of copper and brass PIPE if the gas being transported contains more than .3 grains of Hydrogen Sulfide per 100 standard cu/ft. Bronze and brass FITTINGS are acceptable regardless. Again, copper fittings are prohibited.

2) Unions:
See section 404.3 "Piping in concealed locations". It indicates that unions in concealed locations are acceptable if they are listed for that purpose. Unions in non-concealed locations are acceptable whether listed or not.

Thanks for pointing me in the right direction!

Ken Morley

[RThiede03]

I know the Florida code permits the use of galvanized piping for gas BUT, I sure wouldn't use it at all. The galvanization process "coats" the "black" pipe and in time tends to flake off when used with gas causing obstructions in your orifices, burners, ect.. I would switch to black iron or better yet a csst such as "gas tite" or "trac pipe".

[superfitter]

Originally Posted by RThiede03

I know the Florida code permits the use of galvanized piping for gas BUT, I sure wouldn't use it at all. The galvanization process "coats" the "black" pipe and in time tends to flake off when used with gas causing obstructions in your orifices, burners, ect.. I would switch to black iron or better yet a csst such as "gas tite" or "trac pipe".

That's bull hockey. used to be 20-25 years ago, but galvanizing process is a lot different now. have installed thousands of feet of galvanized pipe with none of those problems. CCST in Florida is a very bad idea. Google it yourself. Won't hold up to lightening strikes nearby. lot's of lawsuits and blown up buildings.

[RThiede03]

So, I Googled it myself. CSST has NEVER had an issue with Lightning strikes when properly bonded. http://www.pipeline-supply.com/notifications/files/gastite/csst%20and%20lightning%20faq.pdf.
Furthermore, I live in Colorado. Have been installing Gastite for 15 years of its 18 year history in U.S. we are subject to lightning storms. Never have had an issue.
Galvanizing may be different now. I don't know. I was simply stating what I would do.

[KMorley]

Superfitter:

Thanks for your reply and I agree with you entirely.

Although I know it's preferred and sometimes even mandated elsewhere, I have NEVER seen black pipe used for gas in our area. I assume the humidity and proximity to salt water would cause black pipe to rust, at least on the outside.

As far as I have seen, galvanized is used exclusively for hard-piping gas in our area. My house has galvanized from the meter into the attic, but there switches to CSST running to the various appliances.

I also agree with you on the CSST. Mine is not grounded, and although I don't believe it has any pinholes, there is visible corrosion (looks like rust) where the yellow outer layer is peeled back for the connector. So much for stainless being rust proof!

As part of this project, I will be running galvanized further into the attic so I can at least cut the CSST shorter and reconnector to eliminate the corroded areas. I will also ground each run to attempt to minimize the lightning threat. I may also coat the exposed stainless with grease to reduce future corrosion, but I don't know how long that will stick in an 140 degree attic.

Do you have any opinion on the use of brass vs galvanized unions in an otherwise all-galvanized gas line? It seems to me that brass would be easier to make seal reliably, but I don't want to do anything verbotten, frowned-upon or unheard of.

Also and for what it's worth, I recall that black pipe is made differently than galvanized and that was the original reason for mandating black pipe. Most black pipe is extruded in one piece from molten steel. Most galvanized pipe is formed from sheet and then welded. I can see a weld seam inside the Mueller galvanized pipe I bought for this project. I don't have any black pipe to compare it to.

Thanks again!

Ken Morley