Electrolysis causing copper pipe to fail?

evosteo

Just had a call off a friend of mine. His sister had a bit of trouble last week. She recently had a new kitchen installed about 2 years ago. New plumbing wiring etc... she heard water running one day last week but the was no taps on. Anyways turns out she found a hole in the copper pipe under the sink. She called the original plumber whos "never seen anything like it before". He disconnected the faulty section, replaced it and sent the faulty bit back to yhe wholesalers who in turn send it back to the suppliers. He heard back today that the suppliers said the copper section failed due to electrolysis which created the leak in the pipe due to the electrics in the house. Iv never heard of anything like this before unless its to do with batteries. Has anyone heard or know how an electrical connection could cause this??? Would poor earting of the copper pipes cause such a problem?? Im just asking before i go up to take a look. Thanks in advance

Stoner

Are they saying this is pitting caused by the electrical cabling

I've heard of piping fail due to the environment it's in.

I've head of pipe failing due to it being poorly produced

I have not heard of this happening in a domestic environment. I cant see how we have electrolysis with the earthing causing it. I assume they are suggesting earthing the pipe and possible earth leakage is part of a cathode, anode and electrolyte circuit.
But I can't see where all the components would come form in a house. I'll ask around about it.

antoinolachtnai

I think they mean galvanic corrosion, like this:

http://www.copper.org/applications/plumbing/techcorner/electrolysis_cause_copper_tube_fail.html

http://www.plainviewwater.org/Approved%20Copper%20Pinhole%20PR%20Response.pdf

Lots of older houses have a galvanised steel tank in the attic.

Electrolysis/galvanic corrosion plates the positively charged to the negatively. So your copper would have to be a higher potential than your equipotential bonding to develop a hole. Even then it's more likely to happen at the junction of dissimilar metals. Usually it's the cable is plated to the chassis on negatively grounded DC systems. A marine electrician will tell you all about it.
I don't think it works with AC.

Stoner

Sir Liamalot wrote:

Electrolysis/galvanic corrosion plates the positively charged to the negatively. So your copper would have to be a higher potential than your equipotential bonding to develop a hole. Even then it's more likely to happen at the junction of dissimilar metals. Usually it's the cable is plated to the chassis on negatively grounded DC systems. A marine electrician will tell you all about it. I don't think it works with AC.

Needs DC, possibly why they are suggesting a stray DC voltage might somehow end up at a equipotental bonded pipe, or sink.

The sink might be another type of metal too.

Pretty common problem in boatland. There's a huge industry around isolation transformers, sacrificial anodes and galvanic isolators to prevent steel hulls disappearing. Of course the electrolytic nature of saline doesn't help.
Modern electronics dump loads of DC to earth.

nmacc

Perhaps there was a nail in contact with the pipe?

I'm guessing its an Fe + Zn + Cu sort of thing, but I'm too lazy to look it up. I have seen it a couple of times where the copper has perforated under the nail.

Having said that I've also seen pipes held up with bent nails that were unaffected for years and lots of pipes held up with galvaband, so it may be something else entirely.

As for electricity, would there be one of those miraculous electrificated water softeners wired to the pipe?