Patent ID: 8235065

Claim:
A method of preparing a control valve having a live loaded packing assembly and an independent secondary seal comprising: providing a valve body having an inlet, an outlet, and a flow passage extending between the inlet and the outlet, providing the valve with a packing box and a bore sized to receive a valve stem; selecting a primary packing set and pacing the primary packing set in the packing box; adjustably coupling only a single packing flange to the valve body; providing a packing follower having a bore sized to receive a portion of the valve stem, the packing follower having an upper portion, a lower portion, and a bearing surface; placing the packing follower into the packing box and positioning the packing follower over the primary packing set, and securing the packing follower in place with a packing flange to thereby apply a first compressive force to the primary packing set; providing the upper portion of the packing follower with threads and an upper counterbore housing a secondary seal ring; applying a threaded nut threaded to the threads of the upper portion of the packing follower to thereby apply a second compressive force to the secondary seal ring; and positioning a spring between the packing flange and the bearing surface of the packing follower; wherein the first compressive force is independent of the second compressive force.