Parameters affecting the weld defect acceptance criteria of clad submarine pipelines installed by S-lay or reel-lay

Abstract

This case study presents a methodology to determine the criticality of defects in submarine pipeline girth welds made of clad carbon steel and to establish weld defect acceptance criteria. The maximum target acceptance criteria are usually given by the applied design code often with additional requirements set by the client. ECA calculations are carried out in order to demonstrate that the target criteria can be met using the relevant material data, geometry and load input. The ECA methodology must follow the defect development from welding fabrication through pipeline installation from the lay barge, as well as consider loads in the as-laid condition during pre-operational and operational phases until the end of design life and verify that leakage or failure will not occur.