Electrity On Copper Water Lines Causing Pipe Deterioration?

[Ravenvalor]

Hello,

I received a call today from a person who was told that electricity may somehow be coming in contact with her copper water lines and causing them to deteriorate rapidly. They took a water sample and found it not to be highly corrosive so I assume they assume that somehow electricity may be deteriorating the lines if the chemicals in the water are not. I asked the customer whether or not they found copper in the water sample and she replied that they did not find a signifigant amount. At first thought this may mean that electricity is not deteriorating the lines however what if the electricity is intermittent? Then the copper would be in the water intermittently. I wonder what color copper water looks like? I wonder if she has any staining of that color in the sinks.

Thanks,

 

[ggunn]

Hello,

I received a call today from a person who was told that electricity may somehow be coming in contact with her copper water lines and causing them to deteriorate rapidly. They took a water sample and found it not to be highly corrosive so I assume they assume that somehow electricity may be deteriorating the lines if the chemicals in the water are not. I asked the customer whether or not they found copper in the water sample and she replied that they did not find a signifigant amount. At first thought this may mean that electricity is not deteriorating the lines however what if the electricity is intermittent? Then the copper would be in the water intermittently. I wonder what color copper water looks like? I wonder if she has any staining of that color in the sinks.

Thanks,

A lot of copper compounds are blue to blue green.

 

[Jraef]

The phenomenon is called "electrolysis" because it does involve "electrical currents", but this is not an electrical issue (as in involving electricians). The electrical current is typically the result of self-generated currents created by someone having connected dissimilar metals together, directly or indirectly*, somewhere in the plumbing system. So for example someone connected the copper pipes to a galvanized steel pipe or fixture. Dissimilar metals in the presence of an electrolyte will cause electrons to flow (what we call electricity) and corrode one or both metals. Potable water is a weak electrolyte, but the presence of chemicals in "hard water" can make that happen even faster.
https://www.copper.org/applications/plumbing/techcorner/electrolysis_cause_copper_tube_fail.html

* Copper to brass is OK because brass has copper in it; galvanized to brass is usually OK because the electrolysis is very weak, but copper to galvanized results in essentially making a battery. That's why you use a dielectric union, it's a device that has a rubber gasket between the dissimilar metals to stop the flow of electrons. Some people, knowing the relative safety of copper-to-brass and brass-to-galvanized, will erroneously think that if they simply use a brass fitting between a copper and galvanized pipe that it prevents electrolysis, but that's a myth. Electrons can still flow.
A piece of plastic piping between them does the same thing, but is often a code problem.

 

[GoldDigger]

T...
Some people, knowing the relative safety of copper-to-brass and brass-to-galvanized, will erroneously think that if they simply use a brass fitting between a copper and galvanized pipe that it prevents electrolysis, but that's a myth. Electrons can still flow.

That is true as long as the length of the brass section is relatively short (like a single fitting) and the water is fairly conductive or the pipe sections are sitting in a wet/conductive fill.
If the only path for the electrolytic current is through the water far enough for the resistance to be large, you can avoid electrolytic damage by using the intermediate metal section.

Similarly, you can mitigate problems between a steel mounting rail in a rack and an aluminum frame member on a solar panel by using stainless steel hardware with a washer to prevent direct contact. That works because (barring acid rain) any environmental moisture will be relatively pure water.

 

[Ravenvalor]

Great replies. I just called the customer who is going to call the plumber.

Thanks.