Abstract: A valve packing assembly for a control valve includes a seal assembly, a loading assembly, and a packing retainer. The seal assembly has a seal component to provide a fluid seal around a valve stem and an anti-extrusion component to substantially prevent extrusion of the seal component about the valve stem. The loading assembly is configured to advantageously provide a predetermined packing stress to the seal assembly that is in the same direction as a process stress applied to the seal assembly by a process fluid, thereby substantially reducing packing friction and packing wear in the control valve assembly.

Abstract: A system and method for accurately measuring supply gas consumed by a particular process control component within a process control system is disclosed. Enhanced measurement accuracy is derived from measuring the consumption of the process control component in a normal operating mode of the process control system. The amount of fluid expended by one process control component is separated by a fluid control system from the amount of supply gas expended in actuating other process control components. The amount of fluid expended by each component may be determined by measuring a decrease in a fluid within a vessel having a known quantity that independently supplies supply gas to each component during its operation.

Abstract: A pneumatic pilot valve comprises a valve body having an inlet, an outlet, a flow passage, and first and second valves arranged to control flow through the valve. The second valve includes a tapered valve seat opening into a cylindrical bore, and a thrust pin includes a tapered second part and an annular recess having a seal. The thrust pin is movable between a first position, a second position, and an intermediate position. The tapered second part of the thrust pin is arranged to engage the tapered valve seat to close the second valve when the thrust pin moves to the second position, and the resilient seal is sized to engage the cylindrical bore when the thrust pin is in the intermediate position.

Abstract: Split packing followers for use with valves are disclosed. A disclosed packing follower includes a first member having a first portion of a flange and a first portion of a curved wall extending substantially perpendicularly from the first portion of the flange to define a first portion of a cylindrical member. The disclosed packing follower further includes a second member separable from the first member. The second member includes a second portion of the flange and a second portion of a curved wall extending substantially perpendicularly from the second portion of the flange to define a second portion of the cylindrical member. The first and second members include complementary interlocking structures that are configured to mechanically couple the first and second members to form the packing follower.

Abstract: A valve assembly has a valve body and a fluid passage through the valve body with an inlet end and an outlet end. A valve seat is defined within the fluid passage. A sleeve is axially slidable within the fluid passage and has an upstream end, a downstream end, and an axial flow passage in communication with the inlet end and the outlet end of the fluid passage. A valve stem is pivotally mounted at a stem pivot spaced radially from the fluid passage. The valve stem is actuable to slide the sleeve between an open position with the downstream end spaced from the valve seat and a closed position with the downstream end borne against the valve seat to selectively control fluid flow through the flow passage to the outlet end. One end of the valve stem is coupled to the sleeve at a joint. The stem pivot accommodates relative axial movement of the valve stem as the sleeve slides within the fluid passage.

Abstract: An apparatus for sealing an operating member of a sliding or rotating assembly includes a seal formed by a composition of materials. A plurality of abrasive particles are incorporated into the composition and thus positioned within the seal. The abrasive particles are disposed to remove an amount of material adhering to the operating member, caused primarily by graphite adhesion. The composition forming the seal can be in the form of a laminate structure, and made of graphite, or graphite and polytetrafluoroethylene (“PTFE”). The plurality of abrasive particles can be selected to be suitable for removing material, while not substantially damaging a surface of the operating member.