B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
B23K9/00—Arc welding or cutting
B23K9/02—Seam welding; Backing means; Inserts
B23K9/028—Seam welding; Backing means; Inserts for curved planar seams
B23K9/0288—Seam welding; Backing means; Inserts for curved planar seams for welding of tubes to tube plates