Girth welding technology used in Heihe-Changling Section of China-Russia Eastern Gas Pipeline

This paper describes the girth welding technology for the north section (Heihe-Changling Section) of China-Russia Eastern Gas Pipeline concerning its characteristics of high steel grade, large diameter, high pressure, large throughput and low temperature. The construction characteristics of welding of D 1 422 mm L555M gas pipeline were summarized in terms of the weldability of L555M pipelines, The performance index of girth welding joint, girth welding technology and quality control. The significance of requirements and test methods for indicators, including the strength, toughness, hardness and plasticity of girth welding joint, were described. The selection principle and actual application of process parameters, such as welding method, welding material and welding groove, were analyzed, and the effect of the groove size, alignment accuracy, preheating temperature and interpass temperature, and NDT technology on quality control of welding was described. All of the above results are empirical summary in engineering construction, capable of providing experience support for the welding construction management in subsequent oil and gas pipeline construction.