External Corrosion Control of Northern Pipelines

摘要

Based on one-year laboratory experiments in which samples were exposed to temperatures as low as -45℃ and two-year data from field experiments, it is concluded that Canadian Standards Association (CSA) standards CSA Z662, CSA Z245.20 and CSA Z245.21 adequately address evaluation of coatings for northern pipelines. However, in order to evaluate the effects of low temperatures, specimens should be exposed for at least four months. Coatings qualified by CSA Z245.21 (System Bl and B2) are less affected by exposure to low temperatures than those qualified by CSA Z245.21 (System A1) and CSA Z245.20.rnCorrosion potentials measured at lower temperatures are in the range of potentials to use the cathodic protection (CP) potential criteria of -0.85 V vs. copper-copper sulphate for northern pipelines.