PACKING SYSTEM FOR VALVES

摘要

A packing system for valves includes a preformed packing, an upper packing cup, a lower packing cup, and a threaded bushing or a gland yoke capable of capturing the upper packing cup when the system is installed in a stuffing box. The preformed packing includes an inner cylindrical shell surrounded by an outer cylindrical shell. Two evenly spaced perforated metal sheets are provided intermediate the inner and outer cylindrical shells. The preformed packing is compressed between the upper and lower packing cups to form a tight seal around a shaft passing through the stuffing box. When the preformed packing is compressed, the perforated metal sheets engage the upper and lower packing cups. When replacing the preformed packing, simply lifting the upper packing cup away from the stuffing box will also cause the preformed packing to be lifted out of the stuffing box.