Electrolytic Corrosion

willasdad

Hoping to find some authoritative resource to confirm or debunk “electrolysis” causing pinhole leaks in pipes. I did read the discussion on dissimilar metals and was as always enlightened by the many true professionals on here about that topic. But what I am hoping to come to some conclusion about is, if stray electric current in a copper water service being used as a ground can cause pinhole leaks? Ask most plumbers and they say yes, but I am finding there is little documentation saying that it actually does. Water quality seems to be the focus, and while I’m sure that alone can cause leaks, can electric current be a sole culprit? I think no, it’s my guess that it’s current reacting to mineral deposits together that’s to blame. Anyone know of the current alone being the proven cause?

STEVEusaPA

It's probably not the sole reason, but unless you have pure distilled water, I'd say the stray current is acting on the impurities.
I was under the impression (read it somewhere) that pure distilled water doesn't conduct electricity, it's the impurities that move the current along.

hot_rod

Here is some reading on that topic.

https://www.copper.org/resources/properties/protection/underground.html

Leonard

Pure distilled water mostly doesn't conduct electricity,...... it's called ~ 18 megohm water ( pretty insulating). Tap water is not pure.

I assume the pipe you are talking about is in air ( not buried).
Thinking of pipe as an electrical wire I don't think stray electrical current along pipe causes pinpoint corrosion. Even if you had many amps flowing along pipe, the voltage drop per inch would be so small it wouldn't even be .01 volt, to drive galvanic corrosion.
Many times on cold pipe it's excess flux during soldering and it gets into pipe, corrodes eventually ( doesn't happen on hot pipe as hot dissolves it out)

EBEBRATT-Ed

Water pipe grounding from the electric service has been used for years without causing pinholes as far as I know.

As @Leonard mentioned excessive flux is a major issue. My boss had this in his house. The hot water piping was fine the cold water kept popping pinholes, hot water flushes out the flux. cold water does not.

willasdad

As always, I appreciate the feed back I get from The Wall contributors, Thank you! Hot Rod, great link, very helpful! Your always on point!

Canucker

> @STEVEusaPA said:
> It's probably not the sole reason, but unless you have pure distilled water, I'd say the stray current is acting on the impurities.
> I was under the impression (read it somewhere) that pure distilled water doesn't conduct electricity, it's the impurities that move the current along

You're right @STEVEusaPA when we use deionized water in our electronic pH meters you can see the readings "bounce", and it stops when minerals or solvents get added to the sample

Gsmith

Electrolytic corrosion can certainly occur from stray electrical currents but can also occur without outside stray currents in any system with dis-similar metals (think iron and copper) and a fluid with salts or minerals--like normal tap water. You have just created a battery and while the current produced may be small over time it can result in pinholes in copper water lines. It is well known that hot water lines can develop pinholes when a water heater lining is compromised and the anode is used up resulting in iron/copper corrosion with the copper being dissolved-the end result is pinholes in the hot water copper lines. My experience is when the pinholes are only in the hot water lines, look carefully at the water heater, probably a compromised lining and little or no anode left.

hot_rod

To Gary's point, here are a few experiments to try.

The ability of water to carry electrical current has much to do with what is in the water, minerals, salts, ions.

Try these with regular tap water, softened water, and purified water from RO, distiller or de-ionizer volume.

While softening water removes scaling minerals it also raises the conductivity of the water through the ion exchange, the brine backwash.

When water is purified to the levels that RO distilling of DI can accomplish the ph will be lowered and the water will become aggressive to copper.

Note this if you ever connect a copper ice maker line to a RO filter.

So while it is good to remove scaling minerals from boiler water, you need to still pay attention to the ph of any purified water you use. hydronic conditioners are a good idea to use in systems with purified water to buffer low ph.

Also don't assume bottled water is purified. Often after some of the bottled water is run thru RO, minerals and often sweeteners are added back in for taste, or to make it more addictive, perhaps

Thanks to Jeff Persons for sharing these pics.

Hot water is more aggressive than cold, which may result in pin holing seen in hot lines and not cold.

Gsmith

Ah, yes hot rod, your are right, hot temperatures almost always increase the speed of chemical reactions. I was thinking of domestic water lines (hot water/cold water lines) when I posted and not thinking about heating system piping,. should have made that clear.

Zman

For initial evaluation, it helps to get an idea of the water chemistry. PH, salinity and TDS is a good start.

From there, figuring out if there is a pattern to the leaks is helpful. If leaks always occur on the bottom of pipe near solder joints, solder is a likely suspect. If it is only on the bottom of pipe on horizontal runs, sediment would be a likely cause. If the leaks are occurring only downstream of fittings, water erosion is likely.
It all gets tricky when there are multiple causes.

Do you have pictures of the pinholed pipes?

Leonard

If use RO (reverse osmosis) to purify then resulting water should be neutral PH, not acidic or alkaline. No chemicals are used, only a RO, and ~ 100 psi water pressure

If use anion-cation ion exchange bed to de-mineralize water, then likely possible to change PH

And obviously steam distillation should be result in neutral PH

Sometimes bottle water is just filled from a city tap and run thru a partical filter so you don't see and crude that might come thru the lines (like rust particals).

hot_rod

Leonard said:

If use RO (reverse osmosis) to purify then resulting water should be neutral PH, not acidic or alkaline. No chemicals are used, only a RO, and ~ 100 psi water pressure

If use anion-cation ion exchange bed to de-mineralize water, then likely possible to change PH

And obviously steam distillation should be result in neutral PH

Sometimes bottle water is just filled from a city tap and run thru a partical filter so you don't see and crude that might come thru the lines (like rust particals).

Hmmm, I learned an expensive lesson putting RO water in a copper ice maker line once.

Everything I've been taught indicates when you strip most everything from water the ph drops, and the drop is logarithmic?

Are there certain water conditions that would not show a drop in Ph thru RO?

I know our mixed resin DI cart drop the ph into the low 6's.

Jamie Hall

On the pH and RO or DI water... in principle, both will have a pH close to 7, slightly temperature sensitive.

But...

They also both have near zero buffer capacity. If there is any possibility of exposure to normal air, the pH will drop -- perhaps substantially -- as carbon dioxide (always present) is dissolved from the air and form carbonic acid. And even weak carbonic acid is remarkably aggressive.

hot_rod

Jamie Hall said:

On the pH and RO or DI water... in principle, both will have a pH close to 7, slightly temperature sensitive.

But...

They also both have near zero buffer capacity. If there is any possibility of exposure to normal air, the pH will drop -- perhaps substantially -- as carbon dioxide (always present) is dissolved from the air and form carbonic acid. And even weak carbonic acid is remarkably aggressive.

Doesn't all water contain some air, and other gases, depending on pressure and temperature? If so is it possible to maintain a 7 ph in a plumbing and heating system filled with purified water?

Leonard

"Everything I've been taught indicates when you strip most everything from water the ph drops, and the drop is logarithmic?"

Don;t know what anion-cation ion exchange bed will do to PH.
But assuming used RO to purify it , would expect PH to stay at neutral 7
But now the water is "soft" and will want to dissolve stuff into it ( like minerals , maybe metals, ect). This just means it can get recontaminated , if you don;t choose your tubing material correctly.

------------------------
PH scale is logarithmic. IIRC from high school chemistry each change in PH level ( ei 7 to 8) is 10 times the concentration of ions (H ....hydrogen ) in the liquid. Think as you go down in PH (acid) the concentration increases.
https://en.wikipedia.org/wiki/PH

willasdad

I dug back into posts from the pipe deterioration section and was amazed at the video tagged to Dans post on copper mystery Thanks HotRod, again! Very interesting information that was never revealed to me in my plumbing and heating “education.”
Since I too live on Long Island, and work not far from Bethpage, I really sympathize with the problem over there. While I say over there, really I mean here. The plume is an enourmous problem, and while it is affecting people in a localized area, it’s really a problem for all of Long Island.
Some twenty years ago I worked for a P and H company and was fortunate enough to work under some great people who taught me so much. One of them was wise enough to turn me onto Dans books. Much time and life decisions have passed and now for some time I have been working at a municipal water supplier on LI. I miss being in the heating world, learning and working on systems, but as life would have it, now I’m just a water guy. But I think it’s great that the pipe deterioration section has been started, and I feel like I can submit a bit more now.
I don’t have any pictures at this time, but I am sure going to start getting them. At the water district I work for, we are fortunate enough to only have to add two things. Chlorine for disinfectant, and Sodium Hydroxide ( caustic soda) for PH control. Many districts opt for Lime to control PH. Chlorine, CL, is necessary for control of bacteria, and we maintain residual CL in the system, not only as a combatant, but as a marker/gauge. Knowing there is CL through out the system tells us that harmful bacteria is not. Caustic soda, Caustic, was put to use in our system a long time ago to control the corrosive nature of the raw ground water. And has been quite effective as the number of service leaks dropped dramatically since it was introduced. Most of these leaks had been taking place on copper services. It is my understanding that it is still not known quite how CL works as a disinfectant. While it’s not aesthetically pleasing, it is easy enough to mostly remove at the point of use. Safer and or economically feasible alternatives are seemingly just not available. People forget that no matter what water is used for, it all has to be at a potable level. Around here anyway. What is considered potable by government standards is getting more and more strict by the year. As restrictions reduce the allowable parts per million of contaminates, the life span of some treatment processes gets reduced dramatically. Granular activated carbon for instance, may still have much useful life left in it for some contaminates, but once it reaches breakthrough for just one type at a strict standard, it must be replaced. This is extremely costly. That being said, I’m all for strict guidelines that are enforced for the benefit of the consumers. People must realize that there comes a point that to treat tens of millions of gallons a day, there must be economic considerations where guidelines are set. That sounds like I don’t care about people’s health, just the bottom line, but that couldn’t be any farther from the truth. It’s just that there will come a point that to treat water to certain levels, it will become so costly to treat water that you would think your paying gas prices per gallon. Fortunately Ph control agents are economical.
In my opinion, And this is with very little background on the specific topic, Grumman should have to pay to remediate the plume. That process as far as I can tell is just a pump and treat and back to the aquifer cycle that will take a very long time. And money. And time is not on our side.
We definitely don’t know a whole lot about water, and it really in my opinion is the greatest force on earth. New contaminates and toxins are being discovered in our aquifer every year. And what are acceptable levels for them is becoming less and less. Aquifer awareness on LI has grown in recent years due to this plume. It’s sad that it takes something like that, but it’s time to take that momentum and keep pushing. Long Island has a sole source aquifer. Without it, all land here will be of no value. Which is why it truly amazes me that we continue to allow practices that we do. Fertilizer for lawns, contains nitrates and ammonia. Anybody who lives on LI knows we have a nitrate issue, yet it continues to be sold. So the Jones’ lawn can be as green as the Jones’ lawn. Could be that ammonia that is getting to the copper. If everyone had brown lawns, then we would all be keeping up with one another. All I’m saying is these practices would never be allowed in drought stricken areas, so it is in my opinion selfish to allow them to continue here. Education is the key, and the only way we can save this sole source so that our great grand kids can drink from it. Certainly this is not just an LI issue, and education on the topic should be standard in schools regardless of region.
So in regard to corrosion by stray current, it would seem the jury is still out, if only by the lack interest, and therefore data. There is strong opinion among professionals that it can and does cause leaks. I have heard time and again, by plumbers and fellow coworkers how ‘electrolysis’ could be to blame for pinhole leaks. It’s even standard for us when we detect amperage on a service, to recommend having the system checked by the power company for a bad neutral. This seemed to be an increased problem after hurricane Sandy ravaged the island. Data regarding this issue is not at this time maintained by the district. And the recommendations to have the electrical systems checked, are mostly in part due to the dangerous condition it creates. Yet there has been many a case that a water service that has a leak, also registered stray current on it. And many a veteran industry professional that would nearly swear by the the current being the cause. Of course there likely has been just as many leaking services that do not have stray current on them. Obviously there is more than a handful of proven causes. Yet while stray current alone may not be a strong contender, I do believe that when present, it certainly is speeding up reactions with deposits and therefore the rate at which a leak will occur. It could be said that a service that has current on it is going to attract more deposits. Which makes it difficult to assign blame since one or the other could arrive first, but not be convicted without the other. Co- conspirators perhaps.

hot_rod

great post willasdad.

Also, everything you flush down the drain goes back into the environment and aquifers. Sludge to landfills, water back into the waterways. Lot of pharmaceuticals are ending up at the treatment plants also, not sure the effect they might have on piping materials, or their interaction with the chemicals used to treat public water? Seems evening television is mainly pharm ads, a pill for whatever ails you, or pills for potential upcoming health issues!

I'm reading more and more chloramine being used instead or in addition to chlorine. Chloramine a derivative of ammonia.

A few point I have read,
"chloramine is too unstable to have it's boiling point measured?
Chloramines used in pools can contribute to respiratory problems, noted by competitive swimmers.
May increase exposure to lead.

4 ppm is the EPAs limit for drinking water. Still a lot to learn about the "universal solvent"

willasdad

Chlorine vs Chloramines, for me, brings to mind the old adage, The devil you know, is better than the devil you don’t know.
Both products have been around for a long time. Chlorine was first used for disinfection in the early 1900’s. 100 plus years is a long time to study the effects of its use for water treatment. Studies of Chloramine use has been far less extensive.
So why the switch? For water suppliers, there seems to be one attractive advantage to chloramine, volatility. Chloramine remains stable in a distribution system for a long time, whereas Chlorine will dissipate. The stable presence of Chloramine insures that holding tanks and distribution systems will fight off regrowth of bacteria. Another reason it has grown in use, is the belief of less disinfectant by-products. Both products when used to treat water will create disinfectant by-products, DBPs. The misunderstanding that Chloramine produces less, is in that it produces less of the regulated and understood DBPs. This doesn’t mean that it doesn’t produce other DBPs that are not regulated. Trihalomethane is the most scrutinized DBP because it is considered possibly carcinogenic. Trihalomethane, THM, is the result of both Chlorine and Chloramine reacting with organics. This is especially a concern when your water source is surface water, ie: lakes, rivers, aqueducts. Ground water is far less likely to contain organics.
In my opinion, there is far greater advantages to Chlorine use. Aside from being pretty well time tested, it is way more effective at killing harmful bacteria, and is much more consumer friendly. Removing chlorine from water is as simple as leaving an open container on your countertop for a day and it will naturally dissipate This is not the case with water treated with Chloramines. Granular activated Carbon, such as in your point of use filter or pitcher-filter will remove chlorine. But only when reverse osmosis is added can Chloramine be removed, and then you are still left with Ammonia. The human body is constantly removing ammonia as a toxic waste. I see no reason to make the job more difficult.
The difficulty in removing Chloramine is passed along to its consumers and industries, both classes are far less challenged by removing Chlorine. Chloramine use has also been attributed to pitting in copper pipes. It’s shown to be far more corrosive when a system switches to it, and therefore requires greater use of anti-corrosion agents. It has been shown to cause greater leaching of lead and lead solder in older homes. Any of these reasons in my opinion is enough to stay with the tried and true chlorine, but certainly a higher likelihood of corrosion is more than enough. I’m no engineer or chemist, i don’t even hold a degree, but I felt it worthwhile to regurgitate from the internet the information above, as we all consume water everyday, but we don’t always go and seek out information on it. The educated consumer is the best consumer.
Sites regurgitated from:
Simplewater.us
Hydroviv.com
Chloramine.org

Gotta love those ads! Pharma with some alien type name cures an ailment, while possibly creating five others! It’s interesting also, that the dangers in those drugs are not just flushing old ones down the toilet, it’s when every user goes to the bathroom. Most of the drug actually goes through the system and right into the toilet!

Bill_Kitsch69

https://forum.heatinghelp.com/profile/willasdad

willasdad said:

Hoping to find some authoritative resource to confirm or debunk “electrolysis” causing pinhole leaks in pipes. I did read the discussion on dissimilar metals and was as always enlightened by the many true professionals on here about that topic. But what I am hoping to come to some conclusion about is, if stray electric current in a copper water service being used as a ground can cause pinhole leaks? Ask most plumbers and they say yes, but I am finding there is little documentation saying that it actually does. Water quality seems to be the focus, and while I’m sure that alone can cause leaks, can electric current be a sole culprit? I think no, it’s my guess that it’s current reacting to mineral deposits together that’s to blame. Anyone know of the current alone being the proven cause?

I have experienced many cases of electrolysis which occurred for a variety of reasons. Electric current can rot ferrous and non-ferrous piping and appurtenances down in no time. Every case must be diagnosed individually. Destructive Electrolysis is very real, not well understood in the trade, and more often than not I'd say not recognized.

HomerJSmith

It is possible, I think, that the copper pipe has impurities in its manufacture. Does anyone know the composition of Type M copper?

Products that raise PH use KOH as the alkalizing agent. I like a PH of 8.5 in my systems.

I would look for scrubbing inside the pipe. Everyone is familiar with dezinctification of brass P-traps over a long period of time and the pin holes that develop. Pin holes develop as a result of ion exchange, I think.

The NEC requires a #6 ground wire from the meter panel to the cold water pipe as well as a grounding electrode. There isn't any current flow with everything at the same potential.