I have some galvanized pipe runs in place that need to be extended. They are natural gas lines for the stove and boiler. Is it allowed by code to combine the galvanized and newer black iron pipe together in the same line? All I need to know if it is allowed by code or not in CT.
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Replies
If that's all you need to know
the best way to find out is to call the BI.
Like the other post indicated, if you are getting a permit and having it inspected you have to ask your local jurisdiction, if you are doing it on your own, some allow, some do not allow, pick one.
I don't see any prohibition but look yourself. This is the ICC Gass code as adopted by Florida
http://ecodes.citation.com/cgi-exe/cpage.dll?pg=x&rp=/indx/ST/fl/st/b1000v07/st_fl_st_b1000v07_4.htm&sid=2010060617490655120&aph=0&cid=iccf&uid=icsc0418&clrA=005596&clrV=005596&clrX=005596&ref=/nonindx/ST/fl/st/b1000v07/index.htm#b=403
http://tinyurl.com/24azsx6
There is some confusion due to the incompatibility of iron and copper pipe. But black iron and galv are both basically iron, and there's no galvanic reaction between them.
Originally black iron and galvanized iron pipes were made differently, and the black iron was less likely to have microscopic leaks. And the corrosion protection offered by (expensive) galvanization was much less necessary with gas vs water pipes. Plus, when galvanized water piping was common, it wasn't unheard of for someone to accidentally connect water and gas lines together, resulting in considerable hazard. For these reasons (mostly no longer valid), galvanized piping for gas lines was discouraged in the past.
But it's all up to the AHJ.
Galv
is either generally discouraged or specifically prohibited, in my narrow experience, due to the possibility of flecks of the galv'ing flaking off and traveling downstream to foul a gas valve or burner. I've also known at least one case where galv fittings were permitted but straight pipe had to be black. It's different everywhere you go.
My last house came with circa 1930 black iron gas lines, and when I worked on them I found a huge amount of rusty powder throughout... found it when I drained air pressure out after a test. I blew them out thoroughly until I couldn't get any more.
This house has black iron that I installed in 2003 and modified in 2007 to move the water heater. It already had the same powdered rust in the lines, albeit a minimal amount. They don't call it hydrocarbon for nothin'!
Last several jobs I've done with gas have used CSST.
Yeah, I forgot about the flaking issue. Probably another red herring, for the most part, since the drip leg should catch 99% of any flakes.
"Originally black iron and
"Originally black iron and galvanized iron pipes were made differently, and the black iron was less likely to have microscopic leaks."
Interesting. Do you have access to any more detail on this?
Just what my grandfather told me.
"Just what my grandfather
"Just what my grandfather told me."
Next, I s'pose you're gonna say it's too late to get more info out of him. :-)
Don't know CT
In DE, "mixing" galvanized and black iron is SOP, and in most rigidly piped residential installations is almost required.
The exposed piping which is outside at the gas meter is required to be galvanized, once inside of the structure the switch is made to black iron (cost driven).
Jim