Face seal assembly

A face seal assembly including a pair of co-operating seal rings, one of said seal rings being provided for mounting on a rotary component and the other on a stationary component, said seal rings having substantially radially aligned seal faces in operation providing a seal gap therebetween for sealing a zone peripherally outward of the seal faces relative to a zone peripherally inward thereof, a plurality of peripherally spaced recesses effective for pumping a gas (hereinafter gas recesses) being provided in at least one of said seal faces, said gas recesses extending from one periphery of said seal face towards the other periphery thereof, while the inner ends of said gas recesses being radially spaced from the other periphery of said seal face, wherein for said seal face having said gas recesses a surface area ratio FGFA/FG being provided, which is in a range between 0.35 and 0.65, preferably 0.4 and 0.6, wherein FGFA=the total surface area of the gas recesses when projected onto the seal face, and FG=the total surface area of the seal face, and wherein a load ratio k, defined as the ratio of an effective surface area FH of the face seal assembly hydraulically loaded by the pressure of the medium to be sealed to the surface area FG of the seal face, is in a range between 0.5 and 1.2.