Mechanised and orbital welding company Polysoude of France has tailored a welding solution for a Russian company to bring safe, quality production practices together with short delivery schedules while keeping costs under control. To satisfy the requirements of the company manufacturing pressure-vessels, a joining system was created using standard mechanized components and offering the optimal welding technique for any wall thickness, any diameter and any material type. The system uses either the plasma or TIG-welding process, or can combine both. With large diameters, there is even the choice to weld either from the outside to the inside, or vice versa. An integrated camera allows for full visual control of the welding process, and the sections consist throughout of low-alloyed or austenitic steel. Their length ranges between 1000 and 3000mm, diameters between 800 and 1500mm and their wall thickness between 5 and 40mm. Polysoude defined to the user the most productive process for every application and developed the corresponding weld programs. Heat input and the addition of filler wire can also be easily piloted and controlled. For components with butt weld preparation and wall thicknesses up to 8mm, the plasma welding with cold wire is the right choice. For bigger wall thicknesses, the procedure combination takes effect: the root is welded with plasma/cold-wire process, the filler and cap pass with the hot-wire TIG process. Depending on material and material thickness, welding speeds reach between 60 and 250mm/min, the number of welding passes is small and the controlled heat input is assured at any time.
