Abstract: In the reliability assessment of the Heihe-Changling Section of China-Russia Eastern Gas Pipeline at the preliminarydesign stage, the basic data of the pipeline sourced from trial-produced steel pipes, while the girth weld data referenced thewelding process adaptability assessment results and previous engineering statistical data. After the pipeline commissioning, itis necessary to check the performance difference between the batch supply steel pipes and the trial-produced steel pipes andthe impact on the service reliability of the pipeline, as well as the impact of automatic welding on the reliability of the pipeline.Based on the new basic parameters, the performance parameters of trial-produced steel pipes and batch-supplied steel pipes werecompared, the mechanical parameters and defect data of automatic welding girth welds were analyzed, and the service reliabilityof the pipeline was rechecked with the latest data. The results show that the mechanical properties of trial-produced steel pipesare different from the batch-supplied steel pipes, but all of them meet the standard requirements. Automatic welding improvesthe quality of girth welds, and the weld performance indexes are all higher than the standard requirements. The fluctuation ofsteel pipe performance directly affects the failure probability value of the pipeline section. With the increase of service life, thefailure probability of the pipeline caused by external corrosion will be gradually increased, but within the 30-year service life, the pipeline is estimated to meet the service reliability requirements according to the current design, materials, construction, operation and maintenance standards.