How do you stop ecectrolisys once it starts to cause pin-hole leaks

[nathan kriss]

I am trying to find out how to stop and prevent further damage of electrolisys. Di-electric unions were not used when they connected new copper mains to old galvinezed units in a hotel. The hot water main has started to have pin-hole leaks. My question is- Can the damage be stopped by installing dielectric unions at all connection points?

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spacey

[Retired plbg1Participant]

You might check water co. and see how hard water is and also install a water Softner a. You might replace pipe with pin holes in first and also Dilectric unions, Did the Plumber say anything about the unions are how come he did not use them , to expensive. Did you have this trouble before you changed pipe.

[nicktheplumberParticipant]

A couple of points:
–Are you sure that the leaks are due to electrolysis?
–If the leaks are due to electrolysis, they will be at the union or within an inch or two of it.
–The lack of a dielectric union does not imply plumbing malpractice. An aceptable way to connect iron pipe to copper pipe also includes the use of a yellow brass nipple between the iron pipe and the copper pipe.

If neither the brass nipple nor the dielectric unions are present, that is a code violation and you should bring the connections up to code.

NtP

[Bruce TParticipant]

–The lack of a dielectric union does not imply plumbing malpractice. An aceptable way to connect iron pipe to copper pipe also includes the use of a yellow brass nipple between the iron pipe and the copper pipe.
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isnt it supposed to be a minimum of 6″ of RED brass??

» This message has been edited by Bruce T on 21 June 2003

[spaceyParticipant]

Thank you for your responding to my questions. This site is going to be very helpful.
To answer your questions, so far I have only looked at the job at the hotel. I wanted to be
sure before I started any work.
The owner of the hotel tries to do everything the cheap way. Apparently he does not
realize that some things must be done the right way first. Or it will cost more in the long
run. He hired a friend of his who knew how to soilder but nothing about plumbing codes.
All of the new copper mains where connected to the old galvanized pipes in the individual
units. He simply did this be using Female copper fittings to galv. nipples.
I need to take a better look at the strapping used for the new mains. Because the pinhole
leaks are not within inches of the unions. They are however occurring one after another
within a 20 foot span. Someone has tried to fix previous leaks by using furnco’s and some
sort of clamp patch that I am not familiar with. Maybe the strapping used is metal, I will
check on that today. I have not replaced any pipe yet but plan on replacing that leaking
section first. Then I will get 6” yellow brass nipples and bring the unit connections up to
code. If the owner will agree, of course. He may want someone just to replace the
leaking section. In that case I will not be doing any work on the building. What are the
consequences for a building owner with code issues on their plumbing?

[nicktheplumberParticipant]

isnt it supposed to be a minimum of 6″ of RED brass??

Oops! You’re correct. I was passing through a “senior moment” of confusion when I typed “yellow” brass. I was also thinking about some valves that I’ve used that are, in fact, golden yellow, and quite well suited to connections to galvanized iron pipe and fittings.

To make amends, I’ll add a few comments about the different types of brass. Brass is an alloy of copper and zinc. Red brass is indeed reddish in color and has about 80% Cu and 20% Zn. Yellow brass has about 60-70% Cu and 40-30% Zn, and is light yellow. It is the zinc which really creates problems with electrolysis, especially in connections to galvanized pipe that are coated with…you guessed it…zinc.

There is, however, a yellow brass that is an alloy of about 90% Cu and 10% Zn. This is called “antique yellow brass.” It is even better than “red” brass for dielectric connections. Fittings, especially valves, are made of this low-zinc “yellow brass.”

Bronze, for those who are interested, is an alloy of copper, zinc, and tin, which, so far as I know, is not used in modern plumbing.

NtP

[GarySlusserParticipant]

There are many causes of pinholes in coper tubing. Electrolysis caused by dissimilar metals and excessive flux are two. Others are high DO, CO2, TDS (total dissolved solids) and chlorides content. Although the last two tend to contribute in errosion rather than corrosion caused leaks. Lightening strikes, low pH (acid water or naturally soft water) with little hardness and alkalinity. Electrical grounds and poor conductivity of the electrical system ground electrode. And finally bacteria of various types. Low pH acidic water is probably the most frequent cause.

A water treament dealer knowledgeable in pinhole causes should be brought in if the owner wants to cure the cause of the problem rather than only treating the symptom; which is probably effecting his galvanized plumbing also. It will be rusting internally and evenutally can clog causing pressure and flow losses.

Here is a http://www.google.com search for “copper tubing” + pinholes (with the quotes), there’s a lot of info on this huge probelm. Also, the current NSF standard 61 (IIRC) limits the use of copper to water with a pH of over 6.5 only.

http://tinyurl.com/4fu1

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Gary
Quality Water Associates

[Bruce TParticipant]

There are many causes of pinholes in coper tubing. Electrolysis caused by dissimilar metals and excessive flux are two.
___________
Does the use of the new “water soluable” flux eliminate pinholes even if used in excess?

[GarySlusserParticipant]

I can’t say, but it would make sense to think so.

Gary
Quality Water Associates

[Author]

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