Low friction live-loaded packing

摘要

A cartridge packing assembly to seal a valve stem in a control valve assembly, the cartridge packing assembly comprising a seal assembly having a seal component to provide a fluid seal around the valve stem and at least a first anti-extrusion component to substantially prevent extrusion of the seal member about the valve stem. A loading assembly having a loading means to provide a predetermined packing stress upon the seal assembly and at least one spacer to couple the loading means to the seal assembly and a packing retainer adapted to be disposed in an outboard packing box of the control valve assembly, the packing retainer defining a packing bore receiving the seal assembly and the loading assembly wherein the packing retainer includes a predetermined length between a retainer shoulder and a loading means seating surface to control a loading assembly force that defines the predetermined packing stress in the control valve assembly.