Tolerable flaw size of girth weld for the 3rd West-to-East Gas Pipeline with a design coefficient of 0.8

In order to reduce pipe consumption and engineering cost, a design coefficient of 0.8 is chosen for a 3 00 kmlongpipeline between 27^# valve station to Yandun Compressor Station on the 3rd West-to-East Gas Pipeline. Comparedwith the previous design coefficient of 0.72, the pipeline safety coefficient is decreased from 1.39 to 1.25, and the pipelinehoop stress level is increased by 11.5%. Aiming at the above features of the 0.8 design coefficient, this paper highlights comparative and differential analysis on the relevant methods and testing standards based on brief introduction of globaldetermination methods of pipeline girth weld defects. According to real working conditions of the pipeline with the designcoefficient of 0.8, engineering critical assessment (ECA) method recommended in API 1104 standard is applied, the tolerableflaw size of the pipeline girth welds is computed and analyzed, and it is thought that the tolerable flaw size prescribed in thenondestructive testing standards of the 2nd West-to-East Gas Pipeline Project is also applicable to the 3rd West-to-East GasPipeline sections with the design coefficient of 0.8.