FRACTURE ASSESSMENT OF PIPELINE GIRTH WELDS USING REVISIONS TO PD-6493

In the early 1980s, full-scale fracture testing of pipeline girth weld s at the University of Waterloo and the Welding Institute of Canada le d to the development of an engineering critical assessment procedure. This was published as Appendix K to the CSA gas pipeline code: CSA Z18 4. The assessment procedure was based on the British CTOD design stand ard, PD 6493: 1980, with empirical corrections intended to provide a c onsistent level of conservatism. The separate collapse analysis, based on ligament yield, while offering considerable improvements, remains very conservative in some cases. In the interim, major revisions to PD 6493 have been accepted. These changes have made PD 6493 more consist ent with the CEGB R6 procedures. This paper will discuss the applicati on of the new PD 6493 Level 2 and 3 assessment procedures to pipeline girth welds. Comparisons will be made between these procedures and the existing CSA standard.