Derivation of Optimal Process Variables for Pipe-flange Welding Using DE Algorithm

In piping spools, the pipe-flange welding process accounts for 30%–70% of the piping manufacturing process. The efficiency of the welding process is important for enhancing the competitiveness of products. Moreover, the development of an automated welding technology required for the production of pipe flanges is being promoted in the industrial sector. In recent years, the productivity of the pipe-flange welding process applied in industrial sites has been improved by using a dual torch to simultaneously weld inside and outside the flange. However, studies on the welding process applied to a dual torch for the STPG 370 and DH36 materials and on the development of reliable optimal process variable derivation and weld bead quality prediction algorithms using mathematical methods are insufficient. Herein, an optimization algorithm was developed for the variables of the pipe-flange welding process to satisfy the flange weld criteria of AWS D1.1/D1 and the ASME code criteria.