Abstract: A metallic, annular sealing device for closing an annular passage between a high-pressure chamber (2) and a circular cover (3) therefor. The sealing device comprises two coaxial, solid rings (17, 18) which are arranged with an intermediate circular gap. An upper (22) and a lower (21) hollow metal ring are each made with a circular gap. The edges of the gap of the upper hollow ring are welded to the solid rings (17, 18) at the upper portion of the gap defined between the solid rings, whereas the edges of the gap of the lower hollow ring are welded to the lower portion of the gap defined between the solid rings. Thus, the hollow rings (21, 22) communicate with each other.