Abstract: Process for manufacturing a plastic hollow body, the process comprising the following steps: a) a tubular stream of molten plastic is extruded; b) this stream is taken up by means of a tensioning device; c) a transverse cut is made in this stream so as to create a parison having one free edge that is not taken up by the tensioning device; d) the parison is moved relative to the tensioning device so that the free edge of the parison is also taken up by the tensioning device; and e) at least one longitudinal cut is made in the parison over its entire length. Equipment suitable for implementing this process.

Abstract: A method for manufacturing a polymeric inner liner for a storage tank, particularly a hydrogen storage tank, comprising: providing a cylindrical body of polymer material, having a first open end and a first peripheral connection tab at the first open end, the cylindrical body comprising a structural layer and a barrier layer; providing a dome-shaped end cap of polymer material having a base with a cross-section essentially corresponding to a cross-section of the first open end of the cylindrical body and having a second peripheral connection tab at a peripheral end portion of such end cap; placing the end cap with its base onto the first open end of the cylindrical body and with the first and second peripheral tabs in contact with each other; and welding both peripheral connection tabs together. A storage tank made using such liner. Use of such tank for storing hydrogen.

Abstract: A device for a venting circuit of a liquid tank provided with a canister and a filling tube including a filling head, this device comprising: a) a control chamber that communicates with: the canister via a main orifice and a smaller-flow-area secondary orifice, both terminating in a ventilation line leading to the canister; the interior of the tank via the venting circuit; and the filling head via a pressure-equalizing line; b) a closure member that is: provided with an opening therethrough which brings the venting circuit into communication with the pressure-equalizing line; able to move in the control chamber between an operating position with the main orifice closed off by gravity and the secondary orifice left open, and a filling position with both orifices left open; and shaped to sealingly conform to at least a control chamber part that includes the main orifice.

Abstract: Method of detecting a leak in a fuel system comprising a fuel tank and an orifice with a controlled section between the tank and the atmosphere, according to which a) the controlled section is set to a value Al at a time T1 and a pressure differential ?p1 between the inside of the tank and the atmosphere is measured at least after an interval of time ?T from T1, for a constant fuel flow out of the tank; b) the controlled section is set to a value A2 at a time T2 and a pressure differential ?p2 between the inside of the tank and the atmosphere is measured at least after the same interval of time ?T from T2, for the same constant fuel flow; c) a ratio of the pressure differentials ?p1 and ?p2 is computed and is compared to a reference pressure differential ratio ?pL obtained with the same fuel system but comprising a calibrated leak.

Abstract: Capacitive gauge for fuel tank comprising a measurement capacitor, a reference capacitor and at least one standard capacitive device, fed by and connected to an electronic interpretation circuit comprising switches for charging and discharging the capacitors and the capacitive device at a certain frequency; an integrator to which the charges of the measurement or reference capacitor can be transmitted and accumulated before being discharged into the standard capacitive device; a comparator for comparing an output value of the integrator with a threshold value; a counter; and a processor or computation unit for calculating the level of liquid in a fuel tank according to the equation: h=[nref,empty/(nref?nref,empty)]·[(nmeas?nmeas,empty)/nmeas,empty], where n are the values read by the counter respectively for the capacitance of the reference capacitor when empty (nref,empty), for the capacitance of the reference capacitor immersed in the fuel (nref), for the capacitance of the measurement capacitor when empt

Abstract: A method for recovering vapor during an onboard refueling operation comprising the steps of: providing a flow path between a fuel tank and a purge canister; providing a valve in the flow path; providing a fuel level sensor for indicating the level of fuel in the fuel tank, and a vapor pressure sensor for indicating the pressure of the fuel vapor in the fuel tank; and actuating the valve to selectively open and close the flow path in response to signals received from the fuel level sensor and the vapor pressure sensor.

Abstract: Valve for the ventilation circuit of a liquid tank, comprising: a) a chamber comprising a base, a side wall and a cover; b) at least two independent ventilation orifices in the chamber cover connecting the chamber to the venting circuit; c) at least one orifice in the chamber side wall connecting the chamber to the inside of the tank; d) at least two independent concentric floats, each comprising an apex capable of sealing one of the ventilation orifices, each being able to slide vertically inside the chamber depending on the liquid level in the chamber and to rest on the chamber base when the chamber is empty; one of the floats being calibrated so as to seal one of the ventilation orifices at one liquid level L1 in the tank and the other float being calibrated so as to seal the other ventilation orifice at a level L2 above L1.

Abstract: A device for a venting circuit of a liquid tank provided with a canister and a filling tube including a filling head, this device comprising: a) a control chamber that communicates with: the canister via a main orifice and a smaller-flow-area secondary orifice, both terminating in a ventilation line leading to the canister; the interior of the tank via the venting circuit; and the filling head via a pressure-equalizing line; b) a closure member that is: provided with an opening therethrough which brings the venting circuit into communication with the pressure-equalizing line; able to move in the control chamber between an operating position with the main orifice closed off by gravity and the secondary orifice left open, and a filling position with both orifices left open; and shaped to sealingly conform to at least a control chamber part that includes the main orifice.

Abstract: Method for manufacturing a plastic fuel tank by moulding a parison in a mould, in which method the parison is locally deformed during moulding of the parison in order to obtain an impermeable hollow built-in connector provided with a screw thread, and to do so by means of a concave counter-form and a convex form that can penetrate the counter-form, these two pieces being secured, one to the mould and the other to a core located inside the mould, or vice versa, and at least one of these pieces being provided with a screw thread, the moulding of the connector taking place by the convex form penetrating the concave counter-form.

Abstract: A urea feed or return line (2) that comprises a hollow coupling (1) enabling it to be connected to a urea tank and that comprises a passage for the urea, this coupling being, in addition, equipped with a heating filament (9), at least one part of which extends freely inside the passage provided for the urea, this part having the shape of a loop or a spiral capable of also extending at least partly into the tank and/or into a tube attached thereto.

Abstract: Method of detecting a leak in a fuel system comprising a fuel tank and an orifice with a controlled section between the tank and the atmosphere, according to which a) the controlled section is set to a value A1 at a time T1 and a pressure differential ?p1 between the inside of the tank and the atmosphere is measured at least after an interval of time ?T from T1, for a constant fuel flow out of the tank; b) the controlled section is set to a value A2 at a time T2 and a pressure differential ?p2 between the inside of the tank and the atmosphere is measured at least after the same interval of time ?T from T2, for the same constant fuel flow; c) a ratio of the pressure differentials ?p1 and ?p2 is computed and is compared to a reference pressure differential ratio APL obtained with the same fuel system but comprising a calibrated leak.

Abstract: Process for manufacturing a plastic fuel tank provided with at least one accessory (14) connected to the internal space of the tank via at least one orifice (12) in the wall (10) of the tank, the accessory including a projecting element (24) extending to the outside of the tank, the processing comprising the steps consisting in providing a film (22) that includes a peripheral region (28) and a border region (30) around an opening in the film, in placing the film on the wall of the tank and on the outer surface of the accessory in such a way that the projecting element passes through the film via the opening, in welding the film over its entire peripheral region to the wall of the tank, and in welding the film, over its entire border region, to the outer surface of the accessory.

Abstract: A method for recovering vapor during an onboard refueling operation comprising the steps of: providing a flow path between a fuel tank and a purge canister; providing a valve in the flow path; providing a fuel level sensor for indicating the level of fuel in the fuel tank, and a vapor pressure sensor for indicating the pressure of the fuel vapor in the fuel tank; and actuating the valve to selectively open and close the flow path in response to signals received from the fuel level sensor and the vapor pressure sensor.

Abstract: Process for manufacturing a fuel tank provided with internal accessories, based on a plastic parison, which is split or in at least two parts, in which process, the accessories are positioned on the parison while it is being moulded, using a core (1) forming part of a mould which also comprises dies (2a, 2b), and in which process, the core is able to move in a controlled manner at a variable speed and/or between optional stop positions of variable duration.

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).