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Old 01-05-2012, 08:47 PM   #1
brit
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Default Electrolosis between galvanized and copper.

Many years ago I added a extra bed room with bathroom. This extension was plumed with copper. The existing house was galvanized. To connect the two together the building inspector told me to use a 6" bronze pipe between the copper and galvanized connection. 15 years later the galvanized connector is showing signs of corrosion ( hot water side ) the cold water side is still OK. I was looking to eventually re-plum with PEX but because there is indirect sunlight under the house apparently PEX may not work without completely covering the plastic pipe.

So the question I want to know is if I replace the bronze pipe with a small PVC pipe. This is on the hot water side and will not be potable just for showers. Will that be a long term problem. The copper is still grounded via the cold water side, will I need to run a jumper to ground the hot water copper side against electrolysis.

Thanks Brit



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Old 01-05-2012, 09:37 PM   #2
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Why not use a dielectric union? After all, that is what they were designed for.



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Old 01-05-2012, 10:07 PM   #3
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PVC pipe is not rated to be used for hot water.

John

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Old 01-06-2012, 01:41 AM   #4
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use a dialectric like havasu has said, john is right about the pvc and you should be aware that they do in fact make uv stabalized pex so sunlight direct or in direct is not an issue.

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Old 01-06-2012, 03:07 AM   #5
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Quote:
Originally Posted by johnjh2o View Post
PVC pipe is not rated to be used for hot water.

John
CPVC Pipe is made for hot tho.
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Old 01-06-2012, 05:02 PM   #6
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Thanks everybody,
I am beginning to wonder why the local building inspector told me to use the bronze pipe. I vaguely remember him saying something about the plastic insulator in the dielectric union breaking down with age. He was old school back then.

Any suggestion on what PEX manufacturer has UV resistant pipe. My local Lowes has Vanguard pipe connectors and tools and is convenient.

Brit

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Old 01-07-2012, 11:41 AM   #7
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CPVC Pipe is made for hot tho.
But no plumber I know actually likes this material for potablle
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Old 01-07-2012, 11:58 AM   #8
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PEX - PEX Products - PEX Supplies - PexSupply.com

thats the link to pex, phone them on the 800 number, Im fairly sure that most pex is now uv stable, but I'd have to check to be sure. aquapex wirsbo im pretty sure is.
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Old 01-08-2012, 08:33 PM   #9
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But no plumber I know actually likes this material for potablle
I don't like it for anything.
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Old 01-09-2012, 12:26 AM   #10
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I agree with you both. I think CPVC will be proven as a bad choice for potable water. We see it being used quite a bit in my area. But when cutting into hot water line of CPVC that has been in service the pipe is so brittle that you can't use PVC cutters on it for fear of it snapping, you have to use a hacksaw. When it hasn't been in service for any length of time it's fine. Are homes down here are on slabs and it's being used under the slabs with fittings. I fear that after time we will be seeing it fail do to it expanding from the hot water with no way to move at the branches. Causing the brittle pipe to crack. PEX may be a better choice.

John



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