Selection principle for welding process of long-distance oil and gas pipeline

Pipeline construction increasingly calls for higher welding quality, efficiency and technology. Therefore, it is essential to choose a reasonable welding process. In this paper, common welding processes of long-distance oil and gas pipelines are systematically coalesced, including shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), semi-automatic welding, and automatic welding, and their characteristics, advantages and applicable conditions are summarized. Moreover, based on practical applications in some major pipeline projects in China, and considering the material grade, diameter, wall thickness, transmission medium, construction environment and other factors, general principles for selecting welding process of long-distance oil and gas pipeline are proposed, which provide a valuable reference to the construction of long-distance oil and gas pipelines.