The ITER project represents a unique challenge for the assembly of workpieces, particularly on site, due to required precision after assembly and last but not least the quality (zero defects). One of the main questions is the pre-conditions required in terms of mechanical preparation, positioning, fixtures necessary but also the unavoidable deformation which occurs in the course of assembly by welding. Narrow Gap TIG Hot Wire welding appears as one of the essential techniques for joining these kinds of parts with such large wall thicknesses, as far as on-site assembly is concerned. This welding process corresponds perfectly to the constraints involved in the final assembly thanks to its all-position use.
