The 2-stage welding process represents a comprehensive welding process separating forming from finish-welding, which has a direct impact on productivity and quality.

Starting from hot-rolled coils, stage one features a 3-roll bending system that forms the input stock into spiral pipes, followed by continuous, high-speed tack-welding. Then the forming station produces an endless pipe strand, which is cut into conventional pipe lengths by a cut-off machine. Next in line, a conveyor system transports the tacked pipes to the submerged-arc welding (SAW) stand. There, they are finish-welded both internally and externally.