What can happen if old galv pipes are mated to new copper and they did not use a dielectric union?
Just had work done and after reading some postings on this site it seems to be a must. Am I going to have problems? If so I can possibly get them to come back and correct the issue.
Also I am thinking of getting rid of all the old galv pipes and was wondering what is the norm to replace it? Copper or PVC?
As always your imput is invaluable.
Replies
A friend of mine bought a house that was built around 1955 with GI pipes. Some worked has been done over the years and part of it was replaced with copper.
I was finishing off the basement redoing a basement "bathroom" (toilet just setting on the floor and the shower was concrete block 'camp ground style'.
I torn everything out except the supply from the street and 3 risers to the 1st floor vanity and toilet. (The tub and kitchen where already copper).
The GI pipe looked like new with a very light coating of minerals on the inside.
The hot riser to the 1st floor vanity had been directly connected to copper. So when I put it back togethr I used a dieletric union. It was leaking when it screwed into the old GI elbow (where the copper had been connected.
Try to tighten it up and the eblow split. Examing the inside of it and the riser the insides where full of gunk and the metal was thin.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
> What can happen if old galv pipes are mated to new copper and they did not use a dielectric union?
The end of the universe as we know it.
Depends on a number of factors, especially the corrosiveness of the water. The first clue that something is wrong is often black water every time you turn on the faucet. Sometimes the iron pipe gets full of corrosion and clogs. Eventually the pipes near the connection will corrode through, but probably for years or even decades.
Galvanic action. The pipes will begin to corrode. It may take a while, but you don't know when they will fail.Replacing pipes now is mostly copper or PEX. Some people (mostly DIY) still use cpvc, but I wouldn't. Copper is nice, but takes some practice and understanding of the components. PEX is pretty simple for basic residential plumbing.
you will have problems my friend most assuredly, just as if you had an old jaguar with lucas electrics (inside joke from another thread)
you can seperate the copper from the galvy with short sections of pex or pvc for a temp fix, long run you will need to replace the galvy, and i would go pex
I just changed out some galvanized nipples that go into a brass elbow which in turn is soldered onto 1/2" copper pipe. The nipples had a certain amount of crud in them but the copper appears in reasonable shape. I assume they have been there since the house was built in 1957. The use of brass between the galv. nipples and the copper tubing my have some moderating effect on galvanic action between the steel and the copper. I am not sure why it would, but I have to that effect.
Yes, the conventional wisdom is that brass reduces the problem significantly.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
We use brass on water heaters, it usually lasts 5-10 years.
-- J.S.