Gas line materials question...

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KMorley

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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
 
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!
 
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.
 
In California, any unions in an enclosed place (walls, attic, etc.) is prohibited but a reverse thread coupling is not.
 
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
 
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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".
 
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.
 
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 and lightning faq.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.
 
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
 
RThied03:

Thanks for your input as well.

I was aware of the lightning issues with CSST prior to Superfitter's reply. The house I live in was built shortly after CSST was first approved and probably before bonding was required.

The lightning here is pretty impressive, so I will be making sure the CSST is well bonded as I complete this project.

Although I know black pipe is preferred in many areas of the world, I have literally never once seen it used for gas here in Tampa. It's permitted by code, but is apparently out of favor with our local plumbers.

Thanks!

Ken Morley
 
Ken, I agree with 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."
I think if you have to do something like that I would try to go with a coupling or or reverse thread coupling. Given that Florida does allow the mix matching of metals I would use a brass union. It will seal better. But, Again, I agree with Phishfood.
 
Here in Mn we use galvanized unions. Properly installed, they don't leak. I put a small amount of rectorseal #5 or subzero on the back side of where the coupling nut turns, no where else.

I used to live and work in So Cal over 15 years ago. Out there Galvanized pipe was not allowed because of the same B.S. beliefs as others had said. Was a real pia to paint the black pipe. Actually I got pretty good at installing plastic roof cement to the pipe with disposable gloves, but i don't miss it one bit. Out there pipe unions weren't allowed due to earthquakes. instead we used left hand/right hand threaded couplings. Here in Mn left hand/right hand threaded couplings aren't allowed also no swing joints or unions in concealed spaces.

kmorley

both black & galvanized 2" and under are continuously welded, larger pipe is seamless.

CCST properly bonded is ok. Looks ok in a residential basement. Looks like crap on a commercial roof and believe me I've seen some really crappy installations that the inspector signed off on. Lately now seeing copper with propress gas fittings on roofs. Ugh!!

:eek:
 
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it sounds like the csst in the attic is track pipe unless they installed the gastite wrong. this is the reason why I like gas tite better. you don't peel the coating back past the fitting which helps protect it from the elements. Also it makes for a cleaner looking job. and as far as the grease idea. if you really want to you could paint/ primer or grease the bare areas but either way I wouldn't worry about it it is just surface rust from moisture and elements the stainless itself will not rust through or cause a leak of any kind. the brass unions are nice for water applications. and could technically be used for gas. but I like to stick with galvanized when I'm running galvanized pipe. I always try to use a right and left hand threaded nipple and coupling when in a bind though and not a union. unions are kind of the handymans way of just getting it done. get rid of that soft copper and put a max. 24 inch ss gas flex on that water heater. copper has been used to run all kinds of gas in the past under slabs asspecially but it is not recomended. and in a lot of places band.
 
Here in canada Galvanized is prohibited due to the flaking mentioned, although it is true that nowadays the pipe is much higher quality in the galvanzing process... that being said it is still illegal, Black iron is preferred over all other methods ( except welded for high pressure and large lines and the plastic lines used by the gas co. ) for plumbers due to its malleabilty and its ability to deform under impact or load instead of breaking. Now, all that being said I imagine galvanized would also oxidize easier, but there is a seperate provisioon in our gas code that states that "any piping exposed to the elements must be painted in a corrosion resistant coating" ( commonly we use trem clad paint ) K morely, why not just paint it?

I have a hard tome to be convinced that a gas line would explode or be ignighted by a lightning strike. it IS already grounded technically as the quickest and most direct path to ground in a home would be the dwv vent if its cast ( unlikely ) or the potablle water piping, which would easily serve as ground. there is not much to ground a meter and the gas is outside the range of flamability for natural gas ( 5-15% ) so how does it ignite? Im not saying "Impossiblle" but I am saying "un likely"
:)
 
Ken, I agree with 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."
I think if you have to do something like that I would try to go with a coupling or or reverse thread coupling. Given that Florida does allow the mix matching of metals I would use a brass union. It will seal better. But, Again, I agree with Phishfood.

by code, not allowed in a concelled space... if you could not use them you would have a hell of a time spinning your furnace around to make the final connection :eek:
 
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