Gas line materials question...

[KMorley]

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

[RThiede03]

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.

[superfitter]

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!!

[zkirtlink]

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.

[LiQuId]

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"

[LiQuId]

Originally Posted by RThiede03

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