Abstract: A control valve includes a valve body, a valve stem, and a control element. The valve body receives the stem and includes a packing box housing a packing set. A packing follower includes a bore sized to receive the stem and includes an upper portion, a lower portion, and a bearing surface, the lower portion sized to extend into the valve bonnet to engage the packing set to apply a first compressive force to the packing set, the upper portion including threads and having an upper counterbore housing a secondary seal ring. A nut operatively engages the threads of the upper portion of the packing follower, the nut positioned to apply a second compressive force to the secondary seal ring, and a spring is positioned between the packing flange and the bearing surface of the packing follower, wherein the first compressive force is independent of the second compressive force.

Abstract: A control valve includes a valve body, a valve stem, and a control element. The valve body receives the stem and includes a packing box housing a packing set. A packing follower includes a bore sized to receive the stem and includes an upper portion, a lower portion, and a bearing surface, the lower portion sized to extend into the valve bonnet to engage the packing set to apply a first compressive force to the packing set, the upper portion including threads and having an upper counterbore housing a secondary seal ring. A nut operatively engages the threads of the upper portion of the packing follower, the nut positioned to apply a second compressive force to the secondary seal ring, and a spring is positioned between the packing flange and the bearing surface of the packing follower, wherein the first compressive force is independent of the second compressive force.

Abstract: A control valve includes a valve body, a valve stem, and a control element. The valve body receives the stem and includes a packing box housing a packing set. A packing follower includes a bore sized to receive the stem and includes an upper portion, a lower portion, and a bearing surface, the lower portion sized to extend into the valve bonnet to engage the packing set to apply a first compressive force to the packing set, the upper portion including threads and having an upper counterbore housing a secondary seal ring. A nut operatively engages the threads of the upper portion of the packing follower, the nut positioned to apply a second compressive force to the secondary seal ring, and a spring is positioned between the packing flange and the bearing surface of the packing follower, wherein the first compressive force is independent of the second compressive force.

Abstract: A control valve of the ball type with bi-directional shutoff capabilities is disclosed. The ball valve including an inlet and an outlet, a ball element and a seal assembly. When closing the valve, the ball element, which is eccentrically mounted on a shaft, rotates to abut the seal assembly. While closed, the seal assembly including a seal housing, a main seal and a resilient member, contacts the ball element at the main seal, while the resilient member biases the main seal toward the ball element. The seal assembly further includes a secondary flowpath between the main seal and seal housing, which is restricted by a high temperature seal.

Abstract: A two-part, low friction, live loaded packing system for fire safety and low fugitive emission sealing (less than 500 ppm) of a valve stem at operating temperatures up to 450.degree. F. (232.degree. C.). One lower packing ring set around the valve stem has PTFE washers sandwiched between flexible graphite rings to provide fire safety and low friction. An upper packing ring set around the valve stem is closer to the loading source and has V-type PTFE rings to provide reliable low fugitive emission sealing and low friction. The live loading is optimized to maintain a seal at the upper packing set to less than 500 ppm leakage, minimize packing friction from both the upper and lower packing sets, and seal the lower packing set during fire safety tests.

Abstract: A fluid valve graphite packing assembly with graphite packing rings and thin PTFE disc rings surrounding an operating valve member. Softer graphite packing rings on the interior are bounded by progressively harder graphite packing rings. A PTFE disc ring is inserted between the graphite packing rings. The packing is subjected to sufficient packing stress to cause the PTFE disc rings to extrude onto the operating valve member. A laminated packing ring formed of alternating sheets of flexible graphite and PTFE which is die cut to provide a crown shaped cross-section aiding in enabling PTFE extrusion to enhance valve operating member lubrication and sealing.

Abstract: A fluid valve capable of operation in high pressure, bidirectional flowpaths includes a chamber having a circular port in which an axially and radially movable seat ring is engaged by an eccentrically movable valve plug having a spherically convex sealing surface. The plug is mounted to a valve shaft supported in the body for rotation about an axis transverse to, but offset from, the centerline of the port. The seat ring, body and a retainer ring include among them a pair of annular channels for retaining a pair of seals adapted for improving their sealing action with pressure.