Abstract: Method for fastening an accessory (2) at at least two points of a wall of a plastic fuel tank, this fastening taking place during the actual manufacture of the tank by molding. According to this method, the accessory (2) is provided, at least at one of its fastening points, with a fastening part (1, 1?) in such a way that the accessory (2) is fastened to the wall of the tank and can move relative to the corresponding fastening point on the wall of the tank (3).

Abstract: Method for fastening an accessory to a wall of a plastic fuel tank, this fastening taking place by snap-riveting using a tool at the same time as the tank is manufactured by moulding, the accessory being, for this purpose, provided at at least one of its fastening points with an orifice through which the snap-riveting is carried out. According to the invention, a concave relief at least partially surrounds this orifice, the relief having a size and shape suitable for being able to cooperate with an excrescence of the tool during the snap-riveting.

Abstract: A process for producing, by molding. a hollow plastic body with a multilayer structure including a liquid barrier layer. In the process: a) a parison including at least one part to be welded is inserted into an open mold including at least two impressions provided with a weld zone to position the part to be welded in the weld zone; b) the mold is closed, juxtaposing its impressions to clamp that part of the parison to be welded and to carry out welding; c) a pressurized fluid is injected into the mold and/or a vacuum is pulled behind the mold impressions to press the parison against the mold impressions and to mold the hollow body; and d) the mold is opened and the hollow body extracted During a) to d), the mold impressions are cooled, exception at the weld zone, which is heated at least during a) and b).

Abstract: Method for fastening an accessory (2) at at least two points of a wall of a plastic fuel tank, this fastening taking place during the actual manufacture of the tank by molding. According to this method, the accessory (2) is provided, at least at one of its fastening points, with a fastening part (1, 1?) in such a way that the accessory (2) is fastened to the wall of the tank and can move relative to the corresponding fastening point on the wall of the tank (3).

Abstract: Method for manufacturing a plastic fuel tank by moulding a parison in which, during the moulding operation, a pipe (3) is attached to the parison at least two points, the said pipe being deformable.