Abstract: Flexible seals for process control valves are disclosed. An example disclosed seal includes a seal for use with a butterfly valve. The example seal includes a substantially flexible ring-shaped carrier configured to be moveably fixed within the butterfly valve and to surround a flow control aperture therein. The example seal includes a seal stiffener adjacent the substantially flexible ring-shaped carrier to increase the stiffness of the substantially flexible ring-shaped carrier in a first flow direction. The example seal includes a substantially rigid seal ring to engage an opposing surface.

Abstract: Flexible seals for process control valves are disclosed. An example disclosed seal includes a seal for use with a butterfly valve. The example seal includes a substantially flexible ring-shaped carrier configured to be moveably fixed within the butterfly valve and to surround a flow control aperture therein. The example seal includes a seal stiffener adjacent the substantially flexible ring-shaped carrier to increase the stiffness of the substantially flexible ring-shaped carrier in a first flow direction. The example seal includes a substantially rigid seal ring to engage an opposing surface.

Abstract: Apparatus to bias valve closure members are described. An example valve includes a valve body having an opening defining a passageway. The opening has an axis that is substantially coaxially aligned with a flow path axis defined by the passageway. A first shaft supports a closure member within the passageway of the valve body and relative to the opening and an end cap removably coupled to the valve body retains the shaft within a bore of the valve body. A spring is disposed between the first seating surface and a second seating surface opposite the first seating surface to provide a force to oppose the weight of the closure member and facilitate alignment of the closure member relative to the opening of the passageway.

Abstract: Methods and apparatus to couple valve shafts and closure members are described. An example coupling apparatus includes an expansion pin to be disposed in a bore defined by a first aperture of a valve shaft and a second aperture of a closure member. The first and second apertures are coaxially aligned when the valve shaft is coupled to the closure member. A first tapered pin is disposed in a first opening of the expansion pin adjacent a first end of the expansion pin and a second tapered pin is disposed in a second opening of the expansion pin adjacent a second end of the expansion pin. The first tapered pin causes the expansion pin to expand at a first location when the first tapered pin is disposed in the first opening and the second tapered pin causes the expansion pin to expand at a second location different than the first location when the second tapered is disposed in the second opening.

Abstract: Flexible seals for process control valves are disclosed. An example disclosed seal includes a seal for use with a butterfly valve. The example seal includes a substantially flexible ring-shaped carrier configured to be fixed within the butterfly valve and to surround a flow control aperture therein. Additionally, the seal includes a ring-shaped cartridge coupled to an inner diameter of the ring-shaped carrier. The cartridge includes a first portion and a second portion coupled to the first portion to define a circumferential opening to hold a seal ring.

Abstract: A seal assembly in a rotary ball valve is installable and replaceable through a bonnet opening in a valve body of the rotary ball valve. The seal assembly includes an anchor ring located in an internal recess in the valve body and one or more seal assembly components, such as a flexible seal member, a seal carrier, a seal retainer, and a rigid seal ring, are secured to the anchor ring.

Abstract: Collets for coupling rotary actuators to valves are disclosed. An example collet includes a plurality of flexible members configured to be coupled to an elongated member and each having an inner surface that forms at least a portion of a substantially rectangular bore configured to receive a rectangular shaft. The plurality of flexible members form an involute outer surface for engaging an involute inner surface of an opening of a lever. The opening of the lever is configured to cause the plurality of flexible members to be displaced toward an axis of the elongated member to cause the inner surface of each of the plurality of flexible members to engage one or more surfaces of the rectangular shaft.

Abstract: Apparatus to bias valve closure members are described. An example valve includes a valve body having an opening defining a passageway. The opening has an axis that is substantially coaxially aligned with a flow path axis defined by the passageway. A first shaft supports a closure member within the passageway of the valve body and relative to the opening and an end cap removably coupled to the valve body retains the shaft within a bore of the valve body. A spring is disposed between the first seating surface and a second seating surface opposite the first seating surface to provide a force to oppose the weight of the closure member and facilitate alignment of the closure member relative to the opening of the passageway.

Abstract: A biasing apparatus includes a first spring seat that has a first seating surface and a first protruding member extending a predetermined distance from the first seating surface and a second spring seat that has a second seating surface and a second protruding member extending a predetermined distance from the second seating surface. The first and second protruding members engage to slidably couple the first and the second spring seats.

Abstract: Methods and apparatus to couple actuator stems and rod end bearings are described. An example apparatus includes a bearing having a body and a portion extending from the body in which the portion includes an internally threaded bore. An actuator stem has a first end that includes an internally threaded bore. An externally threaded stud threadably engages the bores of the rod end bearing and the actuator stem to couple the rod end bearing and the actuator stem.

Abstract: Methods and apparatus to couple valve shafts and closure members are described. An example coupling apparatus includes an expansion pin to be disposed in a bore defined by a first aperture of a valve shaft and a second aperture of a closure member. The first and second apertures are coaxially aligned when the valve shaft is coupled to the closure member. A first tapered pin is disposed in a first opening of the expansion pin adjacent a first end of the expansion pin and a second tapered pin is disposed in a second opening of the expansion pin adjacent a second end of the expansion pin. The first tapered pin causes the expansion pin to expand at a first location when the first tapered pin is disposed in the first opening and the second tapered pin causes the expansion pin to expand at a second location different than the first location when the second tapered is disposed in the second opening.

Abstract: Apparatus to vary the effective spring rate of diaphragm actuators are described. An example spring assembly for use in a diaphragm actuator includes a first spring operatively coupled to a diaphragm plate and an actuator stem, and a second spring operatively coupled to the actuator stem and configured to be serially operative with the first spring. Additionally, a movable spring seat is disposed between the first and second springs.

Abstract: Collets for coupling rotary actuators to valves are disclosed. An example collet includes a plurality of flexible members configured to be coupled to an elongated member and each having an inner surface that forms at least a portion of a substantially rectangular bore configured to receive a rectangular shaft. The plurality of flexible members form an involute outer surface for engaging an involute inner surface of an opening of a lever. The opening of the lever is configured to cause the plurality of flexible members to be displaced toward an axis of the elongated member to cause the inner surface of each of the plurality of flexible members to engage one or more surfaces of the rectangular shaft.

Abstract: Methods and apparatus to couple actuator stems and rod end bearings are described. An example apparatus includes a bearing having a body and a portion extending from the body in which the portion includes an internally threaded bore. An actuator stem has a first end that includes an internally threaded bore. An externally threaded stud threadably engages the bores of the rod end bearing and the actuator stem to couple the rod end bearing and the actuator stem.

Abstract: Apparatus to bias valve closure members are described. An example biasing apparatus includes a first spring seat that has a first seating surface and a first protruding member extending a predetermined distance from the first seating surface and a second spring seat that has a second seating surface and a second protruding member extending a predetermined distance from the second seating surface. The first and second protruding members engage to slidably couple the first and the second spring seats.

Abstract: Apparatus to vary the effective spring rate of diaphragm actuators are described. An example spring assembly for use in a diaphragm actuator includes a first spring operatively coupled to a diaphragm plate and an actuator stem, and a second spring operatively coupled to the actuator stem and configured to be serially operative with the first spring. Additionally, a movable spring seat is disposed between the first and second springs.

Abstract: A method and rotary valve actuator to apply increased torque proximate the open or the closed position of a valve are disclosed. An example rotary valve actuator includes an elongated actuator member and a lever configured to receive a shaft associated with a valve, the lever having a lever arm coupled rotatably to an end of the actuator member, so that when the lever is coupled to the shaft of the valve the elongated actuator member applies a maximum torque to the shaft when the valve is proximate a fully closed or a fully open position.

Abstract: Fluid valve control members having contoured sealing surfaces and methods of making the same are disclosed. An example fluid valve control member includes a body portion having a sealing surface configured to engage a sealing ring within a fluid control valve. A first portion of the sealing surface has a first spherical radius with respect to a first point along a centerline of the body portion and a second portion of the sealing surface has a second spherical radius with respect to a second point along the centerline of the body portion. The first and second points are offset from each other and the second spherical radius is sized to be smaller than the first spherical radius to form a substantially seamless transition between the first and second portions of the sealing surface.