Stuffing box with improved packing rings and method

摘要

A stuffing box 10, 60 designed for sealing engagement with a rod member R includes a plurality of stacked packing rings 32, 110, 150, 210, and a gland member 42, 64 axially moveable relative to the stuffing box body 12, 62 for varying the compressive force on the packing rings. Each packing ring comprises an annular rubber carrier 34, 112, 152, 212 having tapered upper and lower surfaces, and an annular plastic dynamic seal 36, 114, 154, 214 for sealing engagement with the rod member. Gland member 42, 64 exerts an axially compressive force on the radially exterior portion of each angularly wedged packing ring and thereby generates a radial inwardly directed biasing force on each plastic dynamic seal through the rubber carrier for sealing engagement of the dynamic seal with the rod member. Each packing ring includes an annular recess in at least one of the tapered upper and lower surfaces for thermal expansion of the rubber carrier, for flexing of the packing ring, and for increasing radial forces on the dynamic seal.