Bead Prediction of Pipe-flange Welding using Dual Torch

The pipe-spool manufacturing process, which was introduced for manufacturing ship blocks, has an unfavorable working environment. Consequently, the number of workers has rapidly decreased. Recently, the number of orders at shipyards has been increasing. However, at shipyards, saving manpower and meeting delivery deadlines is still challenging, necessitating long-term measures. The pipe-spool manufacturing process is performed by welding pipes and fittings. When welding pipes and flanges, welding must be performed on the inside and outside of the pipe flange seam. Currently, such welding is performed after tack welding. However, the deformation difference becomes large in the work procedure, and the error thus increases in the subsequent process. Hence, an automated device that simultaneously welds the inside and outside of pipes and flanges has been developed. This study predicts bead shapes using the process variables of an automated welding device using a dual torch.