Investigation on Causes of Pitting Corrosion in Sprinkler Copper Tubes

Abstract

Copper metal is widely used in tubes installed in sprinkler water services because of its excellent corrosion resistance. Copper corrosion is considered to be insignificant in water system and the incident of copper pipeline failure is relatively low. However, pitting corrosion is a major problem with all copper tubes. In this study, leaked sprinkler copper tubes were collected from three different locations and examined on the causes of pitting corrosion of copper tubes in sprinkler water plumbing systems. Electrochemical tests such as potentiodynamic polarization, as well as surface and chemical analyses were performed. Results show that pitting corrosion of copper tubes were found as Type I pitting that the carbon film formed on the copper tubes have a harmful effects, causing the pinhole failure in the pipe and resulting in leakage of water. The contermeasures on Type I pitting corrosion of copper tubes were proposed.

Effect of Benzotriazole on the Localized Corrosion of Copper Covered with Carbonaceous Residue

“…A large amount of pitting corrosion occurred within 3–4 years after use in the sprinkler copper tube. As a result of analysis of the leaking tube, it was confirmed that carbonaceous residues were continuously distributed in a thickness of 20–30 μm [ 20 ]. Therefore, to accurately validate the effectiveness of BTA to inhibit corrosion in actual copper pipes, it is necessary to study the effect of BTA on copper with carbonaceous residues.…”

Reduced Copper Piping Corrosion in Sprinkler Facilities

“…2.2 스프링클러 동배관 공식 원인조사 Figure 2는 2차 동배관 부식개선실험 진행 전, 후 보수업 체에서 누수배관을 수거한 것이며, Table 2는 배관에서 발 생하는 동배관 공식의 유형에 따른 공식 전파 및 발생 조 건을 나타내었다. 스프링클러 소화설비는 Type Ⅰ과 Flux induced corrosion 두 유형에 해당된다(2) . TypeⅠ은 40 ℃ 이 Figure2…”