Comprehensive welded pipe technology

2-stage offline production process

Unlike the 1-stage online process, where the pre-formed spiral pipe is directly finish- welded, the 2-stage process separates forming and finish-welding.

Here, we begin with hot-rolled coils as the starting material. 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 a cut-off machine cuts to conventional pipe lengths. Next in line, a conveyor system transports the tacked pipes to the submerged-arc welding stand. There, they are finish-welded both internally and externally. This second stage applies SA-welding technology. What you gain are higher productivity and better quality that meets the requirements of modern, robust pipeline tubes.

Comprehensive welded pipe technology image Comprehensive welded pipe technology image

Size ranges

Pipe diameter

Wall thickness


Tack-welding speed

Main purpose

24" to 64" (max. 100")

610 - 2,540 mm

6.2 - 25.4

160,000 - 260,000

up to 12 m/min

Oil and gas pipelines


Learn about our plant technology covering the entire process chain for the production of high-quality metals.