Abstract: A feedback control system (i.e., a positioner) for precise positioning of a pneumatic actuator by adjusting the flow of air to the pneumatic actuator comprises an adjustable gain mechanism for adjusting the sensitivity of the positioner. The adjustable gain mechanism is coupled between a feedback input device of the positioner and a valve control device and is employed to adjust the amount of air supplied to the pneumatic actuator for a given displacement of the feedback input device. Preferably the adjustable gain mechanism is adjustable through a range of settings between a high gain setting and a low gain setting, the high gain setting allowing a greater range of motion of the valve control device than the low gain setting for a given displacement of the feedback input device.

Abstract: A valve control system for positioning a valve in response to a command signal. The valve control system comprises a sensor for detecting the position of the valve and for generating an outer feedback signal, a valve location command circuit for comparing the command signal to the outer feedback signal to generate a correction signal, an actuator for positioning the valve in response to pneumatic pressure, a spool slidably disposed within a block to direct pneumatic pressure to the actuator, a spool positioning device for moving the spool to a desired position, a spool sensor for detecting the current position of the spool and generating an inner feedback signal, and a spool location command for comparing the correction signal to the inner feedback signal to generate a spool positioning signal to direct the spool positioning device to move the spool to the desired position.

Abstract: A coupling for use in a rotary ball valve having a spherical ball with a passageway therethrough for controlling the flow of fluid through the valve. The coupling is particularly suited for use with non-metallic, for example, ceramic, spherical balls which are rotated by torque applied to a metallic actuator shaft. The coupling includes a plurality of depressions and protrusions formed at the interface of the non-metallic and metallic components. The depressions and protrusions are positioned away from the central axis of the spherical ball. A cushion can be interposed between the metallic and non-metallic components to further disperse the force applied to the non-metallic component. The depression and protrusions can be tapered and oriented at an angle with respect to the central axis so that as torque is applied to the shaft the non-metallic component is rotated without breakage thereof.

Abstract: A pressure modulator includes an electromagnetic coil wire wound about a hollow axle for developing a magnetic field when electrical current is applied to the wire, the hollow of the axle having an entrance port for receiving a fluid and a discharge port for discharging the fluid. The modulator serves to control the pressure of fluid flowing through a conduit under pressure and further includes a bleed-off tap connecting the conduit to the entrance port. A diaphragm plate is disposed above the coil of wire and axle and adjacent to the discharge port of the hollow to modulate the rate of fluid flow from the discharge port. The diaphragm plate includes a central void, a central section of magnetically attractable material disposed in the void above the coil of wire for attraction toward the coil when electrical current is applied to the coil to thereby limit the amount of fluid which is allowed to escape from the discharge port.

Abstract: An integrated process control valve includes a fluid valve body having an inlet for receiving fluid, an outlet for discharging fluid, a fluid flow passage connecting the inlet and outlet, and a controllable throttling element which is moveable to selectively vary the flow rate of fluid through the fluid flow passage.