Automated welding center welding operation by the machine, welding power, welding turning rolls and welding edge crew is composed primarily of large diameter longitudinal weld inside and outside, ring joints, patchwork ball head, cylinder and head butt welding seam, etc. seam welding, submerged arc welding can be automated, MIG / MAG welding, TIG welding, with a variety of cladding welding. In the pressure vessel, petrochemical metallurgical machinery, refrigeration equipment, electrical construction, ship manufacturing, welding and many other industries roll bar has been widely used.