Copper and Galvized connection

[Kevin Luce]

OK, I have a clear understanding why copper and galvanized pipe needs to be separated, but why can't galvanized hangers be used with copper pipe? Unlike a copper pipe connected to a galvanized pipe, the copper pipe and the galvanized pipe hanger do not come in contact with an acid solution. Without the acid solution there is no electro-galvanic action.

Yes, I realized I mis-spelled galvanized in the title.

[Matt Fellman]

It's unlikely that a steel strap on a copper pipe would ever lead to a problem. If the pipe is in a damp/cold area and there's some condensation the chances might be a bit elevated but it's still low.

I've seen this setup more times than I could ever count on houses 30+ years old and have never seen any corrosion, let alone a leak.

The code is written ultra-conservatively and that is likely why it specifies that straps must be the same material as the piping they support.

You're right that it's much more likely at the joint of the piping due to the water. Even that is rare. I'd say for every 20 junctions I find 1 is corroded or leaking.... but I do write those up.... the straps - nope. I'm sure others here will yell and scream that I'm incompetent.

[Ted Menelly]

OK, I have a clear understanding why copper and galvanized pipe needs to be separated, but why can't galvanized hangers be used with copper pipe? Unlike a copper pipe connected to a galvanized pipe, the copper pipe and the galvanized pipe hanger do not come in contact with an acid solution. Without the acid solution there is no electro-galvanic action.

Yes, I realized I mis-spelled galvanized in the title.

Hot,cold, sweating,,= electro-galvanic action

Every other water heater I inspect has corroded connections. Almost always on the cold side. Sometimes on the hot side. Gees. The amount I write up percentage wise is huge. More than 50 percent of the time with out exageration. Some are just starting. Some are seriously corroded.

[Ron Bibler]

Every time copper pipes come in contact with other materials is starts the electro-galvanic action. it may not be at the areas that you see but at some point in the building there is that element to complete the action. if not at faucet then in connection with a drain pipe or a hanger or even something hanging across the pipe. I always make a note about the rust and corrosion. just a note. some may not.

Best

Ron

[Matt Fellman]

Hot,cold, sweating,,= electro-galvanic action

Every other water heater I inspect has corroded connections. Almost always on the cold side. Sometimes on the hot side. Gees. The amount I write up percentage wise is huge. More than 50 percent of the time with out exageration. Some are just starting. Some are seriously corroded.

I should ammend what I said.... I agree with Ted that at least 50% of the water heater junctions are corroded and/or leaking.

My 1 in 20 statistic was related to junctions throughout the other areas.

[Jerry Peck]

It's unlikely that a steel strap on a copper pipe would ever lead to a problem.

That is highly likely that a galvanized strap on copper pipe will cause a problem. So likely that it is prohibited by code.

Would you want to have a leak, cut into a wall, only to find that the pin hole is where the copper pipe was contacting the galvanized strap?

[Kevin Luce]

Thanks for the info everyone.

[Richard Moore]

Took me a while to find this...

1989 home. Most every strap in the crawl looked like the photo. I realize they're not galvanized straps. Draw your own conclusions. I reported it as follows...

Investigate Further and Repair: Most of the copper plumbing in the crawl space has been secured with steel wire hangers. Galvanic action between these two dissimilar metals is causing significant corrosion in many areas. No active leaks were observed but it is possible that some of the piping may be sufficiently damaged to warrant repair. I recommend a licensed plumber replace all of the hangers with those suited for copper piping and, at the same time, clean and check the corroded areas for any damage requiring further repair or replacement.

[Jerry Peck]

1989 home. Most every strap in the crawl looked like the photo. I realize they're not galvanized straps.

Richard,

I realize we concentrated on the term "galvanized", so you did too :) , however, as your photo shows, it is the non-compatibility of materials which is the concern, be that "galvanized", plain steel, aluminum, or any other non-compatible material.

Great photos of what non-compatible materials can do.

[Fred Warner]

Dissimilar metals cause problems for plumbers and electricians. No doubt about it. :)

[Jerry McCarthy]

Depending on the chemical content of the potable water dielectric fittings don't always work so well.

[Glenn Duxbury]

Hi there, All &

* I ALWAYS call-out 'dissimilar metals' in contact with CU (doesn't matter what other type) & have seen many 'leakers' /corroded & 'about to spray'...

Great pics, Guys !


CHEERS