Actual Difference….

[Seven-Delta-FortyOne]

…Between RGS and galvanized gas piping?

I have both side by side in the shop, and aside from the conduit coming with a red plastic protective cap, and the gas line having a yellow one, I can’t find any difference at all.

I slid my finger inside and gave it a good feeling up, , and I can’t feel any difference. Someone once said gas line has a ridge, but I didn’t detect that at all.

 

[curt swartz]

All galvanized plumbing pipe I have worked with has a very rough weld ridge on the interior of the pipe.
I'm surprised you found some that is smooth inside.

 

[ppsh]

I can't say I haven't used nipples from the plumbing aisle at the big box stores before for electrical. Looking through them you can usually find ones with a smooth seam, at least in the snaller sizes.

Havent seen many sticks of galv sch 40 that i'd trust to pull wires through, but I have seen a few pieces that would work.

 

[hillbilly1]

Rigid will not take pressure. I was working on a plant, the maintenance guys used rigid because the local suppliers didn’t have air line, when they put 150 psi on it, it split open.

 

[Eddie702]

If you read some of the really old books, I think pipe and conduit were interchangeable and were exactly the same in the beginning.

I always thought RGS had a thinner wall than galvanized pipe but I could be wrong

 

[dkidd]

 

[don_resqcapt19]

The specifications for ATSM 53 (plumbing pipe) and ANSI C80.1 for conduit show identical inside and outside diameters.

 

[Eddie702]

It is true that BI pipe has a welded seam that can be seen because the pipe is rolled and welded. Don't know about conduit. Black pipe is normally steel pipe. When you buy black pipe you have a choice to buy "seamless" (which is more expensive, used for high pressure critical applications) or the standard black pipe which is known as "ERW Pipe" (electrical resistance welded)

They also make (or made) wrought iron black pipe which some engineers used to spec for underground use because it is more rust resistant.

Wrought iron used to come with a splotch of red or orange paint on it to differentiate it from steel pipe. I remember this from the old days piping fuel oil tanks that were underground.

 

[electrofelon]

I have seen electrical conduit with a more pronounced and rough weld seam than non electrical pipe (not always, it seems to vary a lot), so ive always been skeptical of that theory. Does the product standard address interior finish and toughness? OTOH, ive seen UL put their stamp on so much crap, so manufacturers could be just ignoring that part of it.

 

[Dennis Alwon]

The specifications for ATSM 53 (plumbing pipe) and ANSI C80.1 for conduit show identical inside and outside diameters.

Are the threads the same?

 

[electrofelon]

Are the threads the same?

Yes. There is incredible amount of disinformation floating around there about this but the threads are the same, standard NPT.