Orbital Plasma Arc Welding
High-precision welding process utilizing a constricted plasma arc for tubes with stringent requirements regarding root penetration and process stability.
Orbital plasma welding is a special form of TIG welding. The arc burns between a tungsten electrode and the workpiece, with the plasma constricted through a nozzle. The "orbital effect" is not an extra physical effect, but refers to the machine-guided travel of the torch around the pipe.
The advantage is very good reproducibility and narrow penetration, which keeps the heat-affected zone small. But you have to set current, welding speed and gas post-flow carefully, otherwise you get an uneven weld or penetration defects. Clean edges and exact preparation of the pipe ends are key here, even more so than with normal TIG welding.