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
B23K11/00—Resistance welding; Severing by resistance heating
B23K11/08—Seam welding not restricted to one of the preceding subgroups
B23K11/087—Seam welding not restricted to one of the preceding subgroups for rectilinear seams
B23K11/0873—Seam welding not restricted to one of the preceding subgroups for rectilinear seams of the longitudinal seam of tubes