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http://dx.doi.org/10.14773/cst.2017.16.5.265

Inhibition of Pitting Corrosion of Copper Tubes in Wet Sprinkler Systems by Sodium Sulfite  

Suh, Sang Hee (Center for Electronic Materials, Korea Institute of Science and Technology)
Suh, Youngjoon (Center for Electronic Materials, Korea Institute of Science and Technology)
Kwon, HyukSang (Dept. of Materials Science & Eng., KAIST)
Publication Information
Corrosion Science and Technology / v.16, no.5, 2017 , pp. 265-272 More about this Journal
Abstract
Inhibition of pitting corrosion of the copper sprinkler tubes by removing dissolved oxygen in water with sodium sulfite was studied on the wet sprinkler systems operated in 258 household sites. First, air in the sprinkler tubing was removed by vacuum pumping. The tube was then filled with sodium sulfite dissolved in water. Sodium sulfite was very effective in maintaining a very low dissolved oxygen concentration in water in the sprinkler tube for the observation period of six months. Water leakage from the copper sprinkler tube was reduced significantly by using sodium sulfite. Both pitting corrosion process and pitting corrosion inhibition mechanism were investigated by examining microscopical and structural aspects of corrosion pits formed in failed copper sprinkler tube. Pitting corrosion was caused by pressurized air as well as sediments such as sand particles in copper tubes through oxygen concentration cells. It was confirmed microscopically that growth of corrosion pits was stopped by reducing dissolved oxygen concentration to a very level by using sodium sulfite.
Keywords
pitting corrosion; copper sprinkler tube; sodium sulfite; corrosion inhibition; SEM;
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Times Cited By KSCI : 2  (Citation Analysis)
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1 D. A. Lytle and M. R. Schock, J. Am. Water Works Ass., 100, 115 (2008).   DOI
2 H. Cong, H.T . Michels, and J. R. Scully, J. Electrochem. Soc., 156, C16-C27 (2009).   DOI
3 E. Sarver, K. Dodson, P. Scardina, R. Lattyak-Slabaugh, M. Edwards, and C. Nguyen, J. Am. Water Works Ass., 103, 86 (2011).
4 E. Sarver and M. Edwards, Int. J. Corros., 2012, Article ID 857823 (2012).
5 This Old House, How to stop copper pipe corrosion, https://www.thisoldhouse.com/how-to/how-to-stop-copper-pipe-corrosion.
6 BS EN 1057:1996, Copper and copper alloys- Seamless, round copper tubes for water and gas in sanitary and heating applications (1996).
7 J-B. Lee and H. Jung, Corros. Sci. Tech., 13, 6 (2014).   DOI
8 S. H. Suh, Y. Suh, H. G. Yoon, J. H. Oh, Y. Kim, K. Jung, and H. Kwon, Eng. Fail. Anal., 64, 111 (2016).   DOI
9 J-G. Kim, Research report: Study on the cause of copper tube corrosion, the Korean Institute of Surface Engineering (2016).
10 S. H. Suh and H. Kwon, Wet type sprinkler system for preventing corrosion of metallic water supply tubes, Korea Patent No. 10-1630742 (2016) and 10-1734897 (2017).
11 S. H. Suh, Apparatus and methods for drain, vent and water filling for wet type sprinkler systems, Korea Patent pending No. 10-2017-0032686 and 10-2017-0093215 (2017).
12 S. H. Suh, S. Kim, and Y. Suh, Corros. Sci. Tech., 16, 247 (2017).
13 M. Pourbaix, Atlas of Electrochemical Equilibria in Dissolved waters, Pergamon Press, Houston (1974).
14 M. Edwards, J. F. Ferguson, and S. Reiber, J. Am. Water Works Ass., 86, 74 (1994).