Safe assessment of surface flaw under mismatched weld in offshore pipeline

According to the results of the CTOD(crack tip opening displacement) test and the SINTAP(structural integrity assessment procedure) suggested by Europe Community,the assessment of the surface flaw at the toe of a weld in pipeline was carried out with the given crack size and load.Based on the tensile test results of the base metal and weld metal,the assessment diagram of Level 2 was constructed.The assessment results indicate that the assessment points are within the region defined on the failure assessment diagrams using Level 2.Therefore,the structure containing definite crack can be accepted.The influence of the changes in the depth on the assessed results are greater than that in the length.