Abstract: A valve positioner has a pneumatic transducer responsive to a signal pressure for displacing a spool valve away from a neutral position to effect actuation of an actuator output shaft and further includes a gain adjustment apparatus. The pneumatic transducer includes a balance beam being operably connected at one end to the spool valve and at the other end to a hinge spring. A clamp mechanism is attached to the hinge spring and is slidably adjustable along the length of the hinge spring to vary the spring characteristics. The hinge spring tapers in thickness such that the spring increases in thickness in a direction from a first end of the spring towards the balance beam. A window or cut-out is also provided in the hinge spring to further assist in varying the spring characteristics as the clamp mechanism is moved along the hinge spring, and provide a wide range of gain adjustment over the single spring.

Abstract: A lockout module comprises a housing having at least one lockout bore therethrough, a spindle disposed in the housing and having a pair of lockout cross bores therethrough, and a lockout pin selectively insertable through the housing lockout bore and one of the spindle lockout cross bores for blocking rotation of the spindle relative to the housing in first or second position. Slotted bolt holes spaced through and around the periphery of the housing are utilized to secure the housing to a mounting bracket and valve actuator. The slotted holes allow the housing sufficient rotational travel such that the housing lockout bore can be rotatably aligned with a selected spindle lockout cross bore before securing the bolts, thereby compensating for under or over travel of a valve in the open or closed position.

Abstract: A lockout module is adapted to be mounted between an actuator-to-valve mounting kit and a valve actuator, and is operable to lock the valve in either an opened position or a closed position. In a preferred embodiment, the lockout module comprises a housing, a spindle, a lockout pin, and a lockout tab. The lockout pin is inserted in the housing for selective engagement and blocking of the spindle or for releasing the spindle. A padlock is locked through a lockout wheel on the lockout pin and the lockout tab, the lockout tab engaging a groove within an appendage of the housing to prevent pin and valve movement. In an alternative embodiment, the lockout module comprises a housing, a spindle, a pair of lockout pins, and a pair of pull pins. The lockout pins are inserted in the housing for selective engagement and blocking of the spindle or for releasing the spindle.