Abstract: The improved pre-loaded valve follower sealing apparatus comprises a follower ring and flange insert assembly. The assembly includes a pair of hollow cylinders compressively containing a follower preload and sealing element. That follower preload and sealing element is substantially annular in shape, but has an interior fluid contacting surface which is concave in transverse cross-section when not under compression, but which is rendered substantially smoothly cylindrical when placed under compression.

Abstract: The improved positive pullback synchro valve actuator of the present invention comprises a universal cam assembly having a frame supporting a deformable cam strip which is operatively connected to a plurality of contour adjustment screws and which may be adjusted to form the desired shape of the cam. The cam strip is further operatively connected to a plunger which is disposed for movement transversely of the cam strip and in the longitudinal direction. The apparatus is positive in its pullback, as the plunger is linked to the universal cam assembly, such that when the operator turns the universal cam assembly, there is assurance that the associated valve is closed. In some applications, the plunger may be connected to a shaft yoke which is disposed transversely of the plunger for converting the longitudinal movement into limited reciprocal rotational movement. In these embodiments, the shaft yoke engages a valve shaft which is urged by such yoke into limited reciprocal rotational movement.