pinholes in copper plumbing pipes

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GoldDigger

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How does the process work?
One mechanism is that very turbulent water produces an actual negative pressure region in which a small bubble forms and then collapses, causing a hydraulic shock wave that produces very high surface velocities and forces.
A similar mechanism causes cavitation in poorly designed propellors or ones which are used at too high a speed. Again the symptom (besides inefficiency) is corrosion to the metal surface.
 
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One mechanism is that very turbulent water produces an actual negative pressure region in which a small bubble forms and then collapses, causing a hydraulic shock wave that produces very high surface velocities and forces.
A similar mechanism causes cavitation in poorly designed propellors or ones which are used at too high a speed. Again the symptom (besides inefficiency) is corrosion to the metal surface.
What he said.
 

mgookin

Senior Member
Location
Fort Myers, FL
May not be related to the OP's problem, but if you run RO water through copper pipes, the RO water corrodes copper piping.

What is your source for that information?

RO is just a filtering process at the molecular level. It's about the purest water you can get. How can anyone say that's detrimental to copper piping?
 

sparkyrick

Senior Member
Location
Appleton, Wi
What is your source for that information?

RO is just a filtering process at the molecular level. It's about the purest water you can get. How can anyone say that's detrimental to copper piping?

Google it. This is from Cornell University: "The storage tank, tubing, and dispensing faucet should be made of plastic, stainless steel, or other nontoxic materials. The low pH and mineral content of RO-treated water may corrode copper pipes and allow lead to leach into the drinking water from brass components."

http://waterquality.cce.cornell.edu/publications/CCEWQ-04-ReverseOsmosisWtrTrt.pdf
 

kwired

Electron manager
Location
NE Nebraska
Seems logical if you remove or at least significantly remove minerals from the water it will be more likely to want to collect more minerals again, and pure element metals seem to be easily taken.
 

sparkyrick

Senior Member
Location
Appleton, Wi
We do a lot of car washes. The "spot free rinse" is RO water. Thats where I learned that RO water eats copper. All the piping after the RO filter is plastic or stainless.
 

mgookin

Senior Member
Location
Fort Myers, FL
Google it. This is from Cornell University: "The storage tank, tubing, and dispensing faucet should be made of plastic, stainless steel, or other nontoxic materials. The low pH and mineral content of RO-treated water may corrode copper pipes and allow lead to leach into the drinking water from brass components."

http://waterquality.cce.cornell.edu/publications/CCEWQ-04-ReverseOsmosisWtrTrt.pdf

That's incredible. I always thought RO water was neutral pH. (7 I think?).
 

sparkyrick

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Appleton, Wi
That's incredible. I always thought RO water was neutral pH. (7 I think?).

A plumber told me a disaster story where someone thought RO water would be awesome for his entire house. The homeowner devised a RO system, where the water collected in a large drum and then the RO water was then connected to his plumbing system with a water pump. Yeah, the entire house had to be replumbed because all the copper pipes turned to crap. High $ mistake.
 

K8MHZ

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That's incredible. I always thought RO water was neutral pH. (7 I think?).

Correct. I think they are comparing RO water with un treated water. More important is the low mineral content. Pure water is more 'corrosive' because there is nothing in it to reach a saturation point. High mineral content will leave deposits, low or no mineral content will do the opposite and leach from the surroundings.
 

kwired

Electron manager
Location
NE Nebraska
That's incredible. I always thought RO water was neutral pH. (7 I think?).
I don't think pH is much of an issue, it it the fact that pure water (or nearly pure anyway) has more room for dissolving things then water that already has dissolved content in it.
 
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