Abstract: A shaft seal assembly comprises contact seal rings which are inserted into a recess formed within labyrinth seal rings encompassing the shaft. The contact seal rings are adapted to be in sealing engagement with the shaft when the shaft is not rotating or the shaft speed is relatively slow. The contact seal rings are moved radially outward with respect to the rotary shaft when the shaft speed is increased. Buffer liquid generates the force to move the contact seal rings radially outward from sealing engagement with the shaft and at the same time establishes a barrier for process fluid when the shaft speed is increased.

Abstract: A magnetic pickup for sensing the speed of a rotor disc having a nosepiece affixed to the disc containing one or more magnets. The magnets are contained within blind openings passing inwardly from the back of the nosepiece and arranged to position the magnets within an embossed section extending axially from the outer surface thereof. A stationary sensing probe is mounted adjacent to the embossed section which is capable of generating a voltage signal as the magnets are passed in close proximity with the sensing element.