CuNi Corrosion
CuNi Corrosion
(OP)
Please, any clue as to what may be causing this corrosion?
This pipe is carrying treated, chlorinated drinking water at 45-55 °C.
Water analysis is pH= 6.97-7.87; Salinity 382 mg/lt; Free Chlorine 0.15 ppm (not sure this is always so); Iron 0.75 ppm; Conductivity 600 uS/cm.
Pipes started to corrode 3 years after installation.
This pipe is carrying treated, chlorinated drinking water at 45-55 °C.
Water analysis is pH= 6.97-7.87; Salinity 382 mg/lt; Free Chlorine 0.15 ppm (not sure this is always so); Iron 0.75 ppm; Conductivity 600 uS/cm.
Pipes started to corrode 3 years after installation.





RE: CuNi Corrosion
Was the pipe ever half-full, or drained?
That loose material really doesn't look like the corrosion I'm used to seeing. But I'd like to get other's opinions first..
RE: CuNi Corrosion
When you scrape off (with some difficulty) some of this scale, you find a corroded area below.
Strangely, he leak on theis piece of pipe happened on an isolated pit (see attached pic) on the 12 o'clock position.
I don't know if the pipeline was operated half full or opened, but I presume not because it is carrying potable water for the facility where it is installed.
RE: CuNi Corrosion
RE: CuNi Corrosion
If this is a potable water line we must assume that it may sit stagnant for long periods of time.
MIC is also my thought, though if this deposit contains a lot of metals (Fe, Mn) or S then it simply could be under deposit corrosion.
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Plymouth Tube