Case Study of Coating System for Pipeline Weld Joints

Since late 1990s, most of oil and gas transmission pipeline projects in some Asian countries had adopted Heat-shrink sleeve/tape as field applied coating system for weld joints protection of pipeline with three-layer polyethylene (3LPE) mainline coating. A significant number of disbanded Heat-shrink sleeves/tapes and undercoating corrosion issues were detected during the following In-line inspection and External Corrosion Direct Assessment (ECDA). The cause analysis showed many factors contributed to the large-scale coating failures, such as material suitability, coating application methods, personnel qualification, and defective QA/QC system. This paper will focus on a series of remediation approaches, including an innovative Heat-shrink sleeves/tapes automatic installation system, upgraded QA/QC system, and managerial improvement promoted by top management teams for the case. The purpose of this paper is to raise awareness about QA/QC of coating projects and corrosion management in the pipeline and infrastructure industries.