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AWWA WQTC71476
- Effects of Water Chemistry on Dezincification Corrosion on Brass Plumbing Components
- Conference Proceeding by American Water Works Association, 11/01/2009
- Publisher: AWWA
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Water chemistry had substantial effects on dezincification propensity in systemswhere brass is galvanically connected to copper. It is observed that pH, chloride,alkalinity and sulfate are all influential parameters with respect to the extent ofdezincification. A pH range from 6 to 10 was tested. Both zinc and copper wereleached most rapidly at low pH; however, selective leaching of zinc is highest aroundpH 8. Water higher in chloride or sulfate is more aggressive to brass, and the effects ofchloride are more significant than sulfate. Finally, the conventional theory of"meringue" dezincification suggests that waters low in temporary hardness will havehigher dezincification propensity. Results of this experiment demonstrate that lowhardness, or even softened waters, is not necessarily more aggressive than un-softenedwaters. Rather, it appears that higher alkalinity dramatically decreases dezincification. Includes tables, figures.