NOVELTY - The assembly (30) has a valve (70) that is provided with a valve neck portion formed of a valve material. The sheath is provided with an outer casing surface (22) and an inner casing surface (24). A support element (60) is adapted to cooperate with neck portion and valve casing. The electrically conductive relief surfaces of the annular internal recess and annular outer recess, the electrically conductive support material of support element unit and the electrically conductive outer sealing surfaces of electrical continuity are established between valve and outer casing.    USE - Seal assembly used in pressure tank (claimed) for containing pressurized hydrogen mounted in fuel system for supplying fuel to fuel cell or combustion engine of motor vehicle.    ADVANTAGE - The use of anodized aluminum support elements for seal assemblies of hydrogen storage tanks can be facilitated. The weight of the device can be reduced. The support element is formed with passage from one end to other end, so that the fluid communication between the volume capacity and the duct opening of the valve is facilitated.    DETAILED DESCRIPTION - The casing (20) is formed of a cladding material. The neck of the valve portion is arranged in the protrusion (40). The support element unit is formed of an anodized electrically conductive support material, and is provided with an anodized inner sealing surface and an anodized outer sealing surface. An inner seal is arranged in an annular internal recess formed in the inner sealing surface of the support element unit. An outer seal is arranged in an outer annular recess formed in the outer sealing surface of the support element unit. An INDEPENDENT CLAIM is included for pressure tank for containing pressurized hydrogen.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the pressure tank.    Casing (20)    Outer casing surface (22)    Inner casing surface (24)    Seal assembly (30)    Protrusion (40)    Support element (60)    Valve (70)