Actual Difference….

Seven-Delta-FortyOne

Seven-Delta-FortyOne

Goin’ Down In Flames........
Location
Humboldt
Occupation
EC and GC
…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.
 
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.
 
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.
 
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
 
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.
 
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.
 
There is no "galvanized gas line", there is just galvanized A53, used for both water and gas depending on application.

Sometimes it has an ugly burr inside at the weld, sometimes not, depending on which third world country's machinery was used to manufacture it.

It "appears" to me that RGS suppliers take a little more care about this burr, but from this conversation, maybe not.

The threads on RGS nipples sometimes appear to be made a little differently than on plumbing nipples.
 
Birken Vogt said:
There is no "galvanized gas line", there is just galvanized A53, used for both water and gas depending on application.

Sometimes it has an ugly burr inside at the weld, sometimes not, depending on which third world country's machinery was used to manufacture it.

It "appears" to me that RGS suppliers take a little more care about this burr, but from this conversation, maybe not.

The threads on RGS nipples sometimes appear to be made a little differently than on plumbing nipples.
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True, but since no one has used it for water for the past 70 years, most folks just call it gas line or gas piping.
 
Seven-Delta-FortyOne said:
True, but since no one has used it for water for the past 70 years, most folks just call it gas line or gas piping.
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Back when I did plumbing too (you had to do both to make a living in my town) an old lady had one of the first houses with city water, and even had a generator in an out building for hot water ( house had to be at least 100 years old) anyway, the city sent her an astronomical water bill one month, and told her she had a leak somewhere. Dug up the line, it was a rusted out galvanized line. This was in the 90’s, and she swore up and down she had it replaced a few years back! LOL!
 
Yeah, private hydrants are always 2
1/2 or 3” galvanized.

Reminds me, I need to rebuild the water truck with all 2” galvanized. I don’t think the PVC is going to hold up long term. 😳
 
This was probably 20 years ago, but I remember my Plumber friend (Licensed Journeyman Plumber) said that galvanized pipe could not be used for gas because the galvanizing on the threads could impede the gas seal, even with dope. He said you had to use black iron, as its threads are bare steel. I have no opinion on the validity of this, but this thread had me curious.

Mark
 
busman said:
This was probably 20 years ago, but I remember my Plumber friend (Licensed Journeyman Plumber) said that galvanized pipe could not be used for gas because the galvanizing on the threads could impede the gas seal, even with dope. He said you had to use black iron, as its threads are bare steel. I have no opinion on the validity of this, but this thread had me curious.

Mark
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I’ve heard that before too, but don’t know if it’s true.
I knew a propane installer that would only hand tighten his fittings, he said it’s only 2 psi! 😱
Never did hear of him blowing somebody’s house up though. He had been doing it for about 30 years!
 
hillbilly1 said:
I’ve heard that before too, but don’t know if it’s true.
I knew a propane installer that would only hand tighten his fittings, he said it’s only 2 psi! 😱
Never did hear of him blowing somebody’s house up though. He had been doing it for about 30 years!
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I did a bit of online research. It appears that galvanized is NOT recommended for pluming due to poor corrosion resistance and the possibility of the galvanizing flaking off and clogging lines. Strangely, Black Iron is considered more corrosion resistant due to the coating and the low carbon composition. Learn something new everyday.

Mark
 
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