I had an interesting phone call with a co-worker today. This conversation has come up a couple times in the past on the same building but this time someone is apparently is going to address it. I like to call this a Pandora’s Box question since IMO, there is no definitive proof, just speculation. Kind a like, “Does the ground on a receptacle up or down?”
We have a building that had its boilers replaced a year ago. Since then we have had several pinhole leaks in the plumbing. Prior to the replacement, the 30+ year old pipes have not been a problem to the best of my knowledge. Some suspect electrolysis that is due to leaking current from poor on improper bonding. Is has a 480 volt service with several transformers to kick the voltage down to 120 volts.
The question is, if there is electrical current going through the copper water pipes with bronze, cast iron, and stainless fittings, will the current cause electrolysis? Please back up your answer why you think your answer is correct.
My purpose is to just show the differences out there on the subject. In case you are wondering, the system has a glycol mixture that is acidic free which I do not know the mix ratio is. I’ll be posting this on a couple other boards just to get more feedback.
IMO that in order to have electrolysis, you have to have three elements. There are an anode, a cathode, and an electrolyte. Without all three, you have nothing. The cathode and anodes can not be avoided because of dissimilar metals of the different pipes and fittings. The glycol and or water can work as an electrolyte if the conditions are right. Without all three, there is no electrolysis. Electrical current is the result of electrolysis. Electrolysis is not a result of current.
Short answer: I agree completely with your last paragraph, there's no electrolysis. Long answer: er, technically, yes, there's electrolysis.
There will be electrolysis, but it will be negligible and probably not even measurable. When you pass current through the pipe, voltage is not even across the pipe. Voltage will be higher at the bonding point than at the ground due to voltage drop through the pipe. This creates an electromotive potential that will send small amounts of current through the (poorly conducting) electrolyte, and set up likely immesurable amounts of electrolysis through the pipe. Any oxygen created will eventually react with the pipe, and you'd get a small buildup of hydrogen gas over time.
That is of course if the fluid in the pipe is actually acting as an electolyte. With out an electrolyte, no electrolysis. Thanx for that interpretation. That was good info without all the technical gunk.
We had a lot of poorly made copper piping here in BC from the 70's. The pipe just wore out and developed pinholes. My Aunt was in a 22 story apartment that recently had all the copper pipe replaced. Cavitation can occur in a pipe too. I don't knoe much about that problem however.
#174302 - 02/01/0808:02 AMRe: Electrolysis, bonding, and copper water pipes
Interesting website here discussing the actual cause of pinhole leaks, and it has nothing whatsoever to do with electrolysis, or anything else electrical (well, aside from the electrical forces inherent in a chemical reaction).
Possible causes, as determined by various studies: * Combination of high pH, low organic matter, aluminum solids, and free chlorine * Aggressive water, poor workmanship, and addition of water softeners * Workmanship: Excessive use of fluxes; fluxes are corrosive by their nature * Aluminum-bearing compounds (from concrete pipes, cement mortar lining of cast iron pipes, aluminum coagulant carryover from treatment plants) * Combination of: use of soft waters with low pH; high suspended solids and assimilable organic carbon content; long-term or periodic water stagnation; low or nonexistent chlorine levels; maintenance of water temperatures that promote rapid growth and activity of naturally occurring bacteria; and/or the lack of an adequate monitoring program to periodically evaluate water quality and pipe wall condition * Chloramines, which are chemicals caused by combining chlorine and ammonia (NH3) * Water velocity in undersized copper tubes. For tubing sizes normally installed in home plumbing, the design water velocity should be targeted toward 4 fps. The greatest effect of velocity occurs where the water is forced to change flow direction, such as at elbows and tees, but excessive water flow rates can be damaging to the entire plumbing system. When copper tubing is installed that is too small in diameter for the pressure and flow available, the resulting high flow rates can erode the protective coating creating areas of bare, unprotected copper. This effect can result in a high rate of corrosion wherever the protective coating is eroded.
Urban legends. Pinhole leaks are NOT caused by: * Electrolysis * Grounding of electrical systems/ phone systems to the piping system * Manufacture of the copper plumbing materials * Harmonic divergence (the alignment of the planets) * Solar flares/sun-spots * Cellular phone/radio signals * Cheap/inferior or imported copper
If the pipes that worked fine for 30 years started springing pinhole leaks a year after they were replaced, excessive flux during installation is the most likely cause. Especially if it's a closed-loop where the corrosive compounds just sit. Don't let the plumbers blame the sparkies for their own faulty installation!