Safe assessment for welded joint of offshore pipeline

Structure integrity assessment procedure (SINTAP) sponsored by the European commission was applied to assessment for welded joints of the API 5L X65 pipeline steel with embedded flaw and surface flaw at the weld toe. Given crack size and load, the assessment was carried out according to the crack tip opening displacement test result and using finite element analysis. The failure lines of level 1 and 3 of the weld were derived from the tensile test results. The assessment showed that all assessment points are located within the failure lines of analysis level 1 and 3. Therefore, welded joint of the pipeline is safe. This study laid the foundation of application of SINTAP to pipeline structure assessment.