Sheath for gas insulating breech operating mechanism, and tank null for gas insulating transformer

摘要

PURPOSE:To improve working efficiency by joining a barrel tube and a branch tube with arc welding and joining each part of the barrel tube and the branch tube and flanges with laser beam welding. CONSTITUTION:In a welded structural metal vessel, the metal-made barrel tube 2, the branch 3 joined as branching from the axial direction thereof and the flanges 4a, 4b joined to each end parts of the branch tube 3 and the barrel tube 2, are arranged. Further, each joined part is weld-joined. Then, the barrel tube 2 and the branch tube 3 are joined with the arc welding. Further, each end part of the barrel tube 2 and the branch tube 3 and the flanges 4a, 4b are joined with the laser beam welding. By this method, the mechanical processing efficiency is improved and cost of the material is reduced.