Patent ID: 7963502

Claim:
A valve packing assembly for a control valve assembly, the valve packing assembly comprising: a bonnet; a seal assembly disposed within a packing bore of the bonnet and having a seal component to provide a fluid seal around a linearly slidable valve stem and an anti-extrusion component to substantially prevent extrusion of the seal component about the valve stem; a loading assembly having a loading means providing a loading force that exerts a packing stress upon the seal assembly, wherein the loading force acts in the same direction as a process force generated by a process pressure within the control valve assembly; and a packing retainer having a packing bore receiving the loading assembly upon a seating surface and including external mating threads entirely engaged with internal threads formed in a retainer bore of the bonnet to couple the seal assembly and loading assembly to the bonnet, the packing retainer including a retainer shoulder having a predetermined length, the shoulder abutting an adjacent horizontal mating portion of the bonnet, the predetermined length sized such that the seating surface, the horizontal mating portion, and the loading assembly cooperate to control the loading force and substantially reduce packing friction and packing wear in the control valve assembly.