Abstract: Apparatus for providing a mechanical planar seal, as for example for use with a centrifugal pump having a rotating shaft, includes a primary seal formed of a movable first part rotatable with the shaft and a fixed second part or seat, a secondary seal axially spaced along the shaft from the primary seal, an inlet for flushing liquid, an outlet for the flushing liquid and for pump medium that leaks through the primary seal, a collection chamber defined between the primary and secondary seals for flushing liquid and leaking pump medium, and a drain passage connecting the collection chamber and outlet. The collection chamber is divided into at least two portions in liquid communication with each other and with the drain passage by at least one predeterminately-configured wall so as to assure that the flushing liquid is maintained between the primary and secondary seals for an extended period of time for advantageously efficient use of the flushing liquid in lubrication and cooling of the primary seal.

Abstract: Apparatus for providing a mechanical planar seal, as for example for use with a centrifugal pump having a rotating shaft, includes a primary seal formed of a movable first part rotatable with the shaft and a fixed second part or seat, a secondary seal axially spaced along the shaft from the primary seal, an inlet for flushing liquid, an outlet for the flushing liquid and for pump medium that leaks through the primary seal, a collection chamber defined between the primary and secondary seals for flushing liquid and leaking pump medium, and a drain passage connecting the collection chamber and outlet. The collection chamber is divided into at least two portions in liquid communication with each other and with the drain passage by at least one predeterminately-configured wall so as to assure that the flushing liquid is maintained between the primary and secondary seals for an extended period of time for advantageously efficient use of the flushing liquid in lubrication and cooling of the primary seal.