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Investigation of Rosette Corrosion in Copper Hot‐Water Cylinders
Author(s) -
Oliphant R. J.
Publication year - 2000
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/j.1747-6593.2000.tb00251.x
Subject(s) - copper , corrosion , rod , rosette (schizont appearance) , erosion corrosion of copper water tubes , metallurgy , aluminium , materials science , cylinder , copper wire , engineering , mechanical engineering , medicine , alternative medicine , pathology , immunology , biology
This paper reports upon the premature failure of copper hot‐water cylinders fitted with aluminium protector rods, so‐called ‘Rosette’corrosion. The purpose of the protector rod is to prevent Type 1 copper pitting and has been used successfully for nearly thirty years. The change in composition of waters in contact with cylinders fitted with protector rods, which was monitored over a 12‐month period, established that various species which were aggressive to copper, i.e. nitrite, ammonia and possibly sulphide, were being produced. The potential mechanism for the creation of these ions, and hence the water compositions which are likely to promote Rosette corrosion, are discussed. The change in cylinder design, which is being adopted by manufacturers to overcome this problem in the future, is outlined.