Corrosion Gas Supply Piping

Six year old. Let me repeat that SIX year old home. This is the gas supply piping. What in the world would cause this line to corroded this badly in six years? Could it be that it’s not even galvanized steel? No gas leaks evident at the inspection. But the connection don’t look so hot. Any opinions on this. Gas line is supplying the home and also is connected to a Guardian generator.



You’re in Florida Harry …doesn’t it rain every 15 minutes there? needs paint…

That is the only thing I can think of is that they just installed bare galvanized piping with no paint.

Black iron pipe rusts.

Jim’s right, it needs paint.

I ran a black pipe gas line under a sun room open to air about 6 years ago and it looks similar near the fittings where i brushed on the soapy water to check for leaks…i really need to get that thing wire brushed and painted…I’m going to get right to that…uh well maybe a little later …

Wow, you’re going whole hog.

Around here the gas guys just paint over the rust. :smiley:

Thanks guys!

Surface rust, no biggie. Looks like 3/4" NPT pipe, pretty thick wall on that stuff. Paint it in about twenty years.

i saw your picture of corrosion on google. i am a Professor teaching corrosion. the replies are correct, you are showing surface rust that is all. looks like the screw connections are ok at the moment. the white areas look like slowly failing zinc. watch out for crevice corrosion setting in, so get it coated soon

I was told recently by my local utility that they send a slight negative electrical charge through their gas lines, and this helps minimize corrosion, especially with buried lines. Can anyone confirm?

They do for sure on the large cross country gas pipes in Canada.
All so pipes going through a block wall must be protected most use Plastic electric tape .
Black pipe is normal feed from the meter to the home it too gets painted at installation

If you paint it use oil based paint. If you use a latex the rust will just bleed through the paint in a short amount of time.

I use oil paint getting hard to find .
How do they paint cars with water base paint now.

Funny you mention that Roy a body shop near me had a big sign last year that they switched to all water base paints…doesn’t seem possible but apparently it is, they are a very busy shop…

That is regular black iron pipe, not galvanized. Gas piping is typically done with black iron. It should be protected from corrosion where it passes through the wall, though it may not rust through for decades and decades. I have seen unprotected installations at ground level (exposed to constant moisture and plenty of O2) rust through and leak in five years following installation.

I write it as a defect and suggest that client get around to painting it with a rust preventative paint at some point (not an urgent priority). I always call it on new construction, even for BBQ lines.

Here is the code reference for those not afraid of the IRC: