I’m 99% sure that I already know the answer to this, but thought I would check with some experts.
I met with a lady last night to talk about new cabinets for her kitchen remodel and noticed that someone had made a galvanized to copper transition in a wall without using a dielectric union.
When I told her that I didn’t think that it was kosher, she said that the plumber had told her that a galvanized to brass to copper transition was ok. Since I’ve never heard of that, I though I would check.
I also suggested to her that whatever type of transition is made, it should be under the house and not in a wall.
Feedback, anyone?
Replies
Brass helps.
However... I just replaced some copper line, separated by brass from the galvanized. Corrosion became a problem after a few years.
PAHS works. Bury it.
I've been told that a long brass nipple tends to help as a separation between copper and galvanized. A stainless nipple would be better still for a variety of reasons.
A galvanic union will ELIMINATE the problem entirely, providing it's properly installed.
I would never make such a transition in a location that can't be accessed and monitored. The only place these transitions last well is for treated closed-loop water systems where there's no dissolved oxygen.
I can guarantee you that a brass fitting soldered to a copper line WILL NOT help enough. One of those transitions in the upstairs bathroom of our old house was dripping water down onto my dining room table a couple months after we moved in- and the galvanized pipe was not only corroded enough to be leaking, it was nearly blocked solid with corrosion products too.