Large diameter API / IS Grade pipes with a diameter ranges from 406 mm to 3175 mm, wall thickness upto 25 mm, length upto 12.5 meter and upto and including API 5L X – 80 are manufactured at Varsana H-Saw pipe mills. Annual mill capacity is around 75000 MT per mill.

The making of Spiral Weld pipes :

Hot rolled Coil strip is mounted into the straightening machine. The strip is positioned to the correct helix angle. Before passing the strip through, the leading and trailing ends of the incoming and already inserted coil strip respectively are welded together. The edges are then machined simultaneously on both sides by an edge miller. In the forming section, a 3-roller bending device bend the strip helically into a cylindrical pipe. Then the longitudinal edges of the incoming strip are brought into low point contact and the resulting butt joint is continuously welded externally after a half-turn of the pipe. Finally, it is cut off to the desired length with a plasma torch.

The duly welded pipe is discharged from the Spiral mill for processing of the pipe ends.