| 摘要 |
An improved gas seal having inboard and outboard seal units each defined by a pair of opposed and relatively rotatable seal faces, one face of each pair having appropriate grooves which communicate with a pressurized barrier gas, preferably an inert gas such as nitrogen. The inboard seal unit, at its other seal periphery, communicates with a process fluid being handled by a rotating equipment, namely a pump. Each seal unit has one of the seal rings, the nonrotating ring in the preferred embodiment, urged axially toward its opposed ring by a compact bellows which axially cooperates between the respective seal ring and a backing member. The bellows is positioned to create an isolation between the barrier and process fluids and to provide an effective diameter to provide desirable balance of pressures as imposed on the axially moving seal ring to optimize seal performance. The bellows is preferably a single convolution which is free of fixed securement to the moving seal ring.
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