Copper and steel mix on steam returns.

Ron Jr._3

We replaced a 30+ year old Peerless yesterday. Took some pics of where the return pipe transitions from copper to steel in a wet return.

BTW , the boiler was still ok. Customer wanted to upgrade before it became a problem.

mikeg2015

I’ve been under the belief that you should have brass for a transition between the two. If nothing else, it makes it easier to remove the copper or steel
Pipe some day.

Jamie Hall

Should have brass, perhaps, but certainly not mandatory or the end of the world if you don't.

Ron Jr._3

The transition from copper to steel wasn't the buildup point. It was coated throughout all the steel that was below the normal water line. The copper was still as smooth as a baby's bottom

I've heard that copper can flake off and put the iron. Or turn the system into one big battery. But in practice I haven't seen this phenomenon happen.

EzzyT

I’ve seen plenty of the battery affect on a lot of steam and hot water systems. We use a brass fitting to make the transition from copper to steel or vise versa.

Jamie Hall

Let me add a thought... copper to steel, quite possibly a problem. Copper to black iron... wouldn't worry so much.