A process for manufacturing a hollow body including a thermoplastic wall and a fibrous reinforcement welded on at least one portion of the surface of the wall, or its outer surface, the fibrous reinforcement including a thermoplastic similar to or compatible with that of the wall of the hollow body, having a thickness of at least 1 mm and from 30 to 60% in weight of fibers, the method including heating a portion of the outer surface of the hollow body where the reinforcement will be welded; heating the fibrous reinforcement to soften or melt the thermoplastic of the reinforcement; and moving the reinforcement and applying the reinforcement to the portion of the outer surface of the hollow body. The applying the reinforcement includes: applying an initial pressure on at least one portion of the reinforcement; and applying pressure for a final welding using robotized pressure applying mechanism.