# Galvanized gas line



## sparky (Jan 8, 2014)

got a call the other day and he said that they had gas leak and gas co had turned meter off.we went down there and put test on the line and found where gas co said it was leaking at,repaired those leaks and air it back up and found 4 more leaks that were not there when house was last in use,my question is will galvanized gas lines have leaks come in them after the gas has been shut off??the extra leaks I found were not there when gas was in use and only appeared after the gas had been shut off by gas co.was wondering if the galvanized pipes had moisture or what come in it after the gas was shut off??what caused these leaks???anybody deal with galvanized gas pipe???


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## Shoot'N'Plumber (Apr 27, 2013)

Galvy is used all the time out here and is allowed per code for exposed piping only. Have not seen enough of a difference between the two to determine GALVANISED was more prone. What pressure were you performing yur test at? We're they equally performed with the same procedure i.e. make sure to bleed all air at end of branches. It could just be a fluke though. However, I have experienced this many times before, remember when a leak is present and is severe enough it can lower pressure throughout the distribution system therefore hiding other leaks, then when you fix the most visible one, the pressure increases and simply pops up some where else.


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## plbgbiz (Aug 27, 2010)

How did the pipe look? You could have a corrosion/electrolysis issue.


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## Plumbus (Aug 4, 2008)

sparky said:


> the extra leaks I found were not there when gas was in use and only appeared after the gas had been shut off by gas co.


How do you know that to be so? One shouldn't assume there were no leaks just because no one noticed a mercaptan odor while the system was up and running.


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## sparky (Jan 8, 2014)

Plumbus said:


> How do you know that to be so? One shouldn't assume there were no leaks just because no one noticed a mercaptan odor while the system was up and running.


This is true


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## sparky (Jan 8, 2014)

Shoot'N'Plumber said:


> Galvy is used all the time out here and is allowed per code for exposed piping only. Have not seen enough of a difference between the two to determine GALVANISED was more prone. What pressure were you performing yur test at? We're they equally performed with the same procedure i.e. make sure to bleed all air at end of branches. It could just be a fluke though. However, I have experienced this many times before, remember when a leak is present and is severe enough it can lower pressure throughout the distribution system therefore hiding other leaks, then when you fix the most visible one, the pressure increases and simply pops up some where else.


I was putting 15lbs on the line,and more than likely what you described above is what was taking place,thanks this is what I was leaning toward but this was first time dealing with galvanized pipe!!it leaked at the threaded joints


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## mtfallsmikey (Jan 11, 2010)

Always used black, even outside, but we painted it. Galvy was never used in our area, we heard that the galv. coating could flake off (probably not!), but sounds like someone's dies were trashed during install.


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## MACPLUMB777 (Jun 18, 2008)

mtfallsmikey said:


> Always used black, even outside, but we painted it. Galvy was never used in our area, we heard that the galv. coating could flake off (probably not!), but sounds like someone's dies were trashed during install.


Never had this problem with the galvy flaking, but is probably caused by
a high sulfur content in the gas supply I know this is what makes copper
flake off and is the reason copper was banned for gas, !


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## sparky (Jan 8, 2014)

JERRYMAC said:


> Never had this problem with the galvy flaking, but is probably caused by
> a high sulfur content in the gas supply I know this is what makes copper
> flake off and is the reason copper was banned for gas, !


I think that the the gas line must have had several smaller leaks on it even when it was in use and they didn't show up when the gas in ounces was flowing through it,but when I put the 15lbs on it then it started a chain reaction,also forgot to mention that the known leaks were at the real old gas cocks with the raised head and packing nut at the bottom,most all thee valves leaked and were replaced,it was just weird because we kept finding leaks that supposedly were not there before when gas was flowing threw the line


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## Shoot'N'Plumber (Apr 27, 2013)

sparky said:


> I think that the the gas line must have had several smaller leaks on it even when it was in use and they didn't show up when the gas in ounces was flowing through it,but when I put the 15lbs on it then it started a chain reaction,also forgot to mention that the known leaks were at the real old gas cocks with the raised head and packing nut at the bottom,most all thee valves leaked and were replaced,it was just weird because we kept finding leaks that supposedly were not there before when gas was flowing threw the line


Yea those valves are usually the culprit. Also don't forget, when the system is in use its not getting 15lbs. I've run into this more times than I can count. To show up and fix a leak, then retest at 15lbs and find numerous leaks, then try a 10lb test and the system will hold overnight, but the normal operating pressure is well below that


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## justme (Jul 4, 2012)

sparky said:


> I think that the the gas line must have had several smaller leaks on it even when it was in use and they didn't show up when the gas in ounces was flowing through it,but when I put the 15lbs on it then it started a chain reaction,also forgot to mention that the known leaks were at the real old gas cocks with the raised head and packing nut at the bottom,most all thee valves leaked and were replaced,it was just weird because we kept finding leaks that supposedly were not there before when gas was flowing threw the line


You answered your own question, there's a big difference in a test when you go from 6 ounces to 15 pounds. I tested a thousand feet of old gas line in Sherman Tx that the gas company had shutoff due to a small leak, well when I removed the regulators and put the system on a 10lb test with a diaphragm gauge all hell broke loose and every freaking joint on the roof was leaking plus parts of the black iron yard line that some genius had put in 10 years before. All I heard after the leaks were fixed and the water heaters brought up to code (expansion tanks,make up air and new vents) was why so much for just a little leak lol. It took about 3 days to fix all the leaks and bring all four water heaters up to code.


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## penguinballs (Nov 22, 2014)

Galvanized pipe is black steel diped in a galvanic coating to prevent rust,in doing this it seals and small sand hole imperfections that 
occurs during the manufacturing process & over time could wear off exposing holes hence a leak...black steel only in NY!


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## Redwood (Sep 8, 2008)

penguinballs said:


> Galvanized pipe is black steel diped in a galvanic coating to prevent rust,in doing this it seals and small sand hole imperfections that
> occurs during the manufacturing process & over time could wear off exposing holes hence a leak...black steel only in NY!


How about doing an intro post....

You won't like it here without one...:no:


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## plbgbiz (Aug 27, 2010)

penguinballs said:


> Galvanized pipe is black steel diped in a galvanic coating to prevent rust,in doing this it seals and small sand hole imperfections that
> occurs during the manufacturing process & over time could wear off exposing holes hence a leak...black steel only in NY!


Not sure I ever had it splained to me that way before.


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## HSI (Jun 3, 2011)

Time to spark the debate. Lol
If you use the right dope and tape on every joint this will not happen. When you use the wrong dope only it will dry out over time and moving the line or pressure test will create leaks.


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## plbgbiz (Aug 27, 2010)

HSI said:


> Time to spark the debate. Lol
> If you use the right dope and tape on every joint this will not happen. When you use the wrong dope only it will dry out over time and moving the line or pressure test will create leaks.


...


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## Tommy plumber (Feb 19, 2010)

penguinballs said:


> Galvanized pipe is black steel diped in a galvanic coating to prevent rust,in doing this it seals and small sand hole imperfections that
> occurs during the manufacturing process & over time could wear off exposing holes hence a leak...black steel only in NY!












How in the world did you come up with that user-name?.....on second thought, never mind. I don't care.


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## Gargalaxy (Aug 14, 2013)

Tommy plumber said:


> How in the world did you come up with that user-name?.....on second thought, never mind. I don't care.


Come on Tommy, finish it..... :laughing:


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## jmc12185 (Aug 27, 2013)

I live and work in NY and use galvanized outdoors all the time. What are you talking about black only ???

Sent from my iPhone using PlumbingZone


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## Plumber (Jan 18, 2009)

Edit: durrop...........


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## KoleckeINC (Oct 22, 2011)

Out by me its 5lbs for 15 mins, and that's enough to make new leaks. Gas company does not play! Any leak and they lock it off, even 20 below freezing. Then they need a plumber for a gas pressure test.


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