Forming presses designed for large-diameter line pipe
Graebener-Reika Inc. offers Graebener Maschinentechnik pipe forming presses for producing large-diameter line pipe used in pipeline and utility distribution systems. The presses are suited for producing pipes with increased yield points and large wall thickness-to-pipe-diameter ratios, where the forces required exceed the physical limits of traditional roll bending machines.
The presses can form a variety of pipe sizes without requiring a change of tooling. They can process large-format plates into pipes with diameters of 16 to 64 in., lengths up to 60 ft., wall thicknesses of up to 2.92 in., and grades such as x1200 and x120. For regular wall thicknesses, a special bending shoe can be used to adapt the machine.
The longitudinal edges of the metal plate are first given a chamfer. Then, through a series of steps, the plate is bent into a final O shape, creating an open tube that first is tack welded and then submerged arc welded at a separate station.