Potable Water Fittings

Are these steel/iron fittings allowed on potable water in your area? (disregard the missing vent)

The fitting is a threaded nipple and 90° for expansion balder on a water heater, off the potable water copper piping. It is not on the main potable drinking water line.

IMO, it is part of the water pipe distribution and must be potable.

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No, they are not. Iron pipe is not listed in the water distribution table.


Yes it is. So are you telling me that a 12 inch air chamber on a fixture is not part of the water distribution system because water does not travel through it on a regular basis?

Water most definitely goes in and out of an expansion tank every time the hot water is turned on and turned off.


This is what IPC 2018 lists as approved. (GA follows IPC)

Martin, do you know if any part of that iron pipe is considered ductile (maybe the elbow)?

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It looks like malleable iron pipe from here. Gas pipe fittings. Even sprinkler fittings look very different at the hub.

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No, it is not correct. Black pipe(iron pipe) is not approved for potable water supply, and that is part of the supply. Simple fix, just replace with galvanized steel pipe.


Simon didn’t you already know the answer to your question before you asked it?

Thank you everyone for you replies. I focused on the steel thinking Galvanized steel. Ops.
The reason behind my post is that, oxygen isn’t regularly introduced to that application.
I would write up no visible dielectric fittings. Chance of corrosion.

Sort of, I’m trying to figure out what place the guy who plumbed that in comes from :smiley: So far, maybe Canada.


Regardless of where he came from, he needs to install according to local codes. I don’t even know if iron pipe is approved in Canada. I’m sure the queen will chime in with some copy and paste information.


Not approved for potable water pipes.

Your use of degrading members you do not agree with on the forum is obvious.
You should learn how to conduct yourself on the forum.



How do you get a threaded pipe under that t-fitting? No support!.

Good catch.