Receptacle for the storage of fluid under pressure

Receptacle for the storage of fluid under pressure and of the type comprising an internal casing with a form of revolution around a longitudinal axis X, X' and having one central cylindrical section and two extremity sections, at least one of said extremity sections being bulged outwards so as to be a convex extremity, an armoring of resistant fibers coated with hardenable bonding material and encompassing said casing and having at least one planetary winding leaving open to said convex extremity section a cap centered on said axis X, X', wherein the outer contour of said convex extremity section of the casing has, as a longitudinal section, a shape which is at least approximately elliptical so that the ratio G of the small half axis to the major axis is such that:

• 0.32.ltoreq.G.ltoreq.0.4 (I)
• where the major axis corresponds to the external diameter of the central cylindrical section of the casing and wherein the thickness e.sub.i of said convex extremity section of the casing, said cap being excluded, varies according to the formula:
• ##EQU4## in which:
• R.sub.i =distance to the axis X, X' of the point of the outer contour of said convex extremity section at which the thickness e.sub.i is measured,
• e=thickness of the casing at its central cylindrical section,
• R=external radium of the central cylindrical section of the casing,
• R.sub.1 =radius of the base of said cap, and
• e.sub.1 =thickness of the casing for R.sub.i =R.sub.1, the thickness of said cap being at least equal to e.sub.1.