This paper investigates the applicability of cathodic disbondment (CD) test at higher temperatures, i.e., up to 150 deg C. This paper also presents different factors affecting applicability of the CD test at higher temperatures. It was found that CD Experiments are relevant for high-temperature coating evaluation up to 150 deg C. Maintaining temperature of the experimental pipe section simulates conditions as those of hot pipes. Slow evaporation of water occurs. The rate of water evaporation decreases in the presence of soil - the extent of which depends on the type of soil. Conducting the experiments in an autoClave is not an adequate way to conduct high-temperature CD tests because it does not simulate the temperature differentials that occur under pipeline operating conditions. While conducting long-term experiments care should be exercised to avoid evaporation of electrolyte. Evaporation can be prevented or minimized by refluxing the electrolyte, replenishing the electrolyte, or by covering the experimental set up. The thickness and thermal conductivity of a pipeline coating affect how much heat is transmitted from a hot pipe section to the soil it is in contact with.
Relevance of cathodic disbondment test for evaluating external pipeline coatings at higher temperatures
2009
15 Seiten, 24 Quellen
Conference paper
English
Betriebsbedingung , Bindefestigkeit , elektrochemische Reaktion , elektrolytischer Prozess , Erdboden , Haftfestigkeit , Hochtemperatureigenschaft , Hochtemperaturkorrosion , kathodische Polarisation , Pipeline , Prüfung im Einsatz , Rohrkorrosion , Rohrleitungskorrosion , Umgebungsbedingung , Wärmebeständigkeit , Wasserdampf
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