Best pipe for gas

My old gas lines are looking pretty corroded so I'm investigating alternatives for replacement. I'm looking for low-corrosion alternatives, having dealt with replacing a lot of corroded house parts of various kinds.... And you know a corroded gas line stands a good chance of not being properly attended to....

I don't understand why anyone would use black pipe for gas. Is this now outlawed in some jurisdictions? Galvanized seems better, but stainless is surely the best for corrosion resistance. I also like that there are no intermediate fittings to leak with CSST. Yet CSST appears to be the supply medium that plumbers on this board love to hate.

If the problem is concern at the lack of protection against nails, well we run electrical cables through conduit in areas where it needs protecting (NEC has provision for it), so why not the same with CSST? Run the flex cable through black pipe. I don't think there's much galvanic interaction between steel and SS (unlike galvanized and SS).

If black pipe is too heavy to work with, then run it through electrical conduit.

If people are balking at running BP to every gas outlet in the house....well that's how my house has been plumbed anyway.

I guess the pipes wil be oversized and heavy. If a HO is crazy enough to hang the pipes, would you run the flex through it for him? Remember, we don't care about the air-tightness of the fittings....

black iron in an indoor environment should never rust out. underground or out of doors is different. galvanized used to be PROHIBITED, for the reason that flakes of the galv. coating could come off and clog valves and orifices. I don't think it is considered an issue any more.

If you were to put the flex inside any sort of sleeve, the sleeve would be required to be sealed on one end, and ventilated to the out of doors on the other end. Would be bad news to have a sleeve which might contain and exposive mixture from a leaky fitting or whatever.

pipe

You are thinking of stainless steel piping from a theoretical point of view. You obviously have never worked with it in a plumbing environment, or you would realize how difficult it is to cut threads that do not tear and thus leak.

Thanks for your replies!

While I assumed nat gas is corrosive, I gather most of the issue is interaction of sulphur with copper and zinc.

The corrosion I've seen on black pipe is largely in a damp crawlspace, so presumably largely external.