Galvanized pipe in the gas line....

rvr6000 · Oct 14, 2011

Don't know how I never noticed this before but this morning while working on a couple projects in the basement I noticed the gas line to the water heater has a galvanized elbow and a 2 or 3 inch galvanized ****** stuck in between the rest of the black pipe. I've been in the house ten years so I guess it's been like that at least that long.

I'll fix it this weekend but I guess I've never really known why black pipe was always used over galvanized. Can someone clue me in? Thanks.

69satelite · Oct 14, 2011

rvr6000 said:
Don't know how I never noticed this before but this morning while working on a couple projects in the basement I noticed the gas line to the water heater has a galvanized elbow and a 2 or 3 inch galvanized ****** stuck in between the rest of the black pipe. I've been in the house ten years so I guess it's been like that at least that long.

I'll fix it this weekend but I guess I've never really known why black pipe was always used over galvanized. Can someone clue me in? Thanks.

galvanized is usually for use in outdoor applications

chickenhauler · Oct 14, 2011

When I re-plumbed my house I used whatever I had on hand, which was mostly galvanized. Black iron is cheaper - If I had to buy pipe for gas lines, It would be black iron.

rvr6000 · Oct 14, 2011

Is there generally a code requirement for black pipe to be used?

chickenhauler · Oct 14, 2011

It depends on the area and local codes from what I understand.

71flh · Oct 14, 2011

I think the theory is that the zinc would/could flake off and clog burners.

jimp · Oct 14, 2011

I think that back in the olden days black iron was seamless, while galvanised was welded seam.

Some codes have not caught up. However, even ones that allow, still do not allow mixing material.

rvr6000 · Oct 14, 2011

Thanks everyone....this gives me a good excuse to make it right and put in a decent quarter-turn valve too. Need a pliars to open/close that old one that's on there now.

chickenhauler · Oct 14, 2011

rvr6000 said:
Thanks everyone....this gives me a good excuse to make it right and put in a decent quarter-turn valve too. Need a pliars to open/close that old one that's on there now.

I've spent a fortune on 1/4 turn ball valves. I think there were 2 shut offs total in the house, and they were old gate valves that leaked around the stem if they were touched. My gas is oily enough that the insides of the 60 year old lines I took apart look a little like a diesel exhaust. Flaking of galvanize isn't one of my concerns lol.

mrobins297aaa · Oct 14, 2011

I think one of the main reasons that you were not suppose to use galv. pipe on gas years ago was because the water lines were galv and if you used galv on the gas pipe they would look the same and they didn't want people cutting into a gas line thinking it was water................I also heard about the flakeing off of the galv but I've never ever heard of anyone having a problem with it

tabascokid · Oct 15, 2011

FYI, galvanized is legal for gas by state code in Ohio, however I will agree black is the prefered industry standard

kbs2244 · Oct 16, 2011

The flakeing possibilty is the real reason for what are called "drip legs" in gas piping.
The flakes will fall into the leg.
The gas companies spen big money to keep moisture out of the gas lines.
But the fear of the flakes in the first place is why many gas companies will not allow galvanized.
The term "drip legs" comes from compressed are piping, where water in the pipes is a real problem, and is just carried over since it looks exactly the same.

ptschram · Oct 16, 2011

If it ain't broke, don't break it!

A_Pmech · Oct 16, 2011

I wouldn't take the entire system apart just for one galvanized elbow!

sberry · Oct 16, 2011

Same here, I am sure I could find other hazards to my property greater than a couple galv fittings. Main reason it isn't galv on gas is that it doesn't "need" to be, water lines need to remain clean. Might make some changes should I have to replace heater but am with the "not broke don't fix" unless there is some obvious reason to suspect a future problem.

CaseyJoes. · Oct 16, 2011

71flh said:
I think the theory is that the zinc would/could flake off and clog burners.

If i'm correct, I believe this is the same reasoning why black iron is code for lines in air compressor systems in shops etc?

BadgerBoilerMN · Oct 20, 2011

Galvanized pipe is OK of natural gas - if you run out of black pipe but galvanized pipe should never be used for propane service.

fireguy · Oct 21, 2011

At one time I did a lot of gas work, natural and propane. Once, and only once, when I took a drip leg apart, shiny metal flakes fell out. The pipe line was galvanized. I use black pipe because that is what we use for water and chemical fire suppression systems.

HoosierBuddy · Oct 21, 2011

Black pipe is preferred due to the flaking issue.

Drip legs are always recommended, but if they are necessary is another question. Natural gas can contain significant amounts of heavier hydrocarbons at times and these can and do condense to liquids in gas lines. These liquids tend to get pulled towards low elevations and high draw customers. So, if your house is at the bottom of a hill, you are more likely to see them. If you're a farmer and you have a 5 mmbtu/hr grain dryer you are likely to see them too.

Right now, most US gas is really dry. That changes year-to-year based on what the midstream is doing with liquids. Right now it makes good $ sense to strip them all out of the gas stream and sell them in the liquids market. In 2008, it was just the opposite.

Phil

qmdv · Jul 13, 2020

I just did a search on what pipe to use on propane gas lines. This came up and I would like to make a few comments. Let me first say that I was a plumber for just under 50 years most of the time running a plumbing contractor business. First there is no code on steel pipe for air lines. The engineer that does the specifications make that call. I have done both gal and black.

Early on in my career we always used black pipe for both natural and LP gas. We used galv ******* and fitting because we ran both water and gas in steel pipe and by using galv ******* and fittings we did not have to double stock stock. The code actually said that black or gal was ok for all gas. In the early 80's I had a red tag put on one of my jobs because of gal *******. I had to prove to the building officials that I was correct.

I did the search because I am going to run a new LP gas line in my house and it has been a long time since I checked that code. It looks as if it has changed and I will be doing all black this time around

59 wagon man · Jul 13, 2020

leave it alone

Jim greengo · Jul 13, 2020

We used to have to do everything in black pipe for gas,I still do though.
Now a days gas co doesnt worry about galvanizing flaking off and burning,they say screen in gas valve will catch it.
I still point it out when I see it on something I'm working on,I'd rather not have to change out a gas valve that gets plugged full of trash myself.

Rusty Fords · Jul 14, 2020

Just to chime in here, I've done a lot of gas pipe over the years both commercial and residential. From what I have seen in Oregon we used Galvanized on the coast only due to salty air rusting the black pipe out, Use Black pipe inland for both Propane and natural the possibility of Gal flaking of and getting in the gas valve. Drip legs I never had to clean one out other then one on a Industrial site they had a 2' piece of 2 1/2" pipe as a drip leg it would fill with oil within a year. I was told by the gas company it was most likely due to one of the pumping stations pumps high pressure lube system was leaking oil into the gas line and because the place used so much gas it would end up there.

yeldogt · Jul 14, 2020

I have always had to run galvanized pipe outside for NG ... Always thought this was funny as the stub out and pipe up from plastic main installed by the gas company was black pipe and painted ... same with the short line into the house ..black. The pipe after the "T" outside to my grill and pool had to be all galvanized .. anything underground had to be wrapped.

My outside connections for my house with propane are all galvanized

sberry · Jul 15, 2020

Dont mess with it.

engineer2 · Jul 15, 2020

I think natural gas is a lot cleaner than it used to be. In the 70's in rural Oklahoma when we opened up a furnace burner manifold it would be half full of acidic sludge, but we were burning about 24,000 cubic feet/hour.

nadogail · Jul 15, 2020

IMHO If it isn't broke, don't fix it.

LS6 Tommy · Jul 18, 2020

rvr6000 said:
Is there generally a code requirement for black pipe to be used?

Not any more. Galvanized is now accepted by code for natgas.

Tommy

Galvanized pipe in the gas line....

Well-known member

Active member

Well-known member

Well-known member

Well-known member

Banned

Well-known member

Well-known member

Well-known member

Well-known member

Member

Well-known member

Well-known member

Well-known member

Banned

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Banned

Well-known member

Well-known member

Well-known member