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Thread: Copper and Galvized connection
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01-17-2009, 10:42 PM #1
Copper and Galvized connection
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.
Similar Threads:Last edited by Kevin Luce; 01-17-2009 at 10:45 PM. Reason: Added last sentence.
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01-17-2009, 11:05 PM #2
Re: Copper and Galvized connection
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.
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01-17-2009, 11:09 PM #3
Re: Copper and Galvized connection
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.
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01-17-2009, 11:11 PM #4
Re: Copper and Galvized connection
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
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01-18-2009, 12:00 AM #5
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01-18-2009, 02:02 PM #6
Re: Copper and Galvanized connection
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01-18-2009, 04:12 PM #7
Re: Copper and Galvanized connection
Thanks for the info everyone.
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01-18-2009, 04:14 PM #8
Re: Copper and Galvized connection
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.
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01-18-2009, 05:01 PM #9
Re: Copper and Galvanized connection
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.
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01-18-2009, 05:52 PM #10
Re: Copper and Galvized connection
Dissimilar metals cause problems for plumbers and electricians. No doubt about it.
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01-20-2009, 07:11 PM #11
Re: Copper and Galvized connection
Depending on the chemical content of the potable water dielectric fittings don't always work so well.
Jerry McCarthy
Building Code/ Construction Consultant
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01-21-2009, 03:36 PM #12
Re: Copper and Galvized connection
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
-Glenn Duxbury, CHI
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