Steam admission valve structure for steam turbines

Claim 1

A steam admission valve structure for steam turbines comprising a fixed member formed with a plurality of passages disposed vertically and arranged in side-by-side relation, each of said passages being provided at its upper end with a valve seat, a one piece valve lift bar mounted above said seats for movement toward and from the same, said bar being formed with an aperture axially aligned with each of said valve seats, a split bushing mounted in each of said apertures, retaining means detachably mounted in each of said apertures for fixing each of said bushings against axial movement relative to said bar, a valve cooperable with each of said seats, each of said valves having a stem extending through one of said bushings and being slidable therein, each of said valve stems being formed with an integral enlarged head portion, and said head portions being dimensioned for passage through said apertures and engageable by the bushings upon upward movement of said lift bar, each of said apertures being formed with a shoulder spaced downwardly from said retaining means, each of said bushings being formed with a radially extending flange positioned intermediate to said shoulder and said retaining means, said retaining means being positioned upwardly from said shoulders a distance exceeding the axial thickness of said flanges, a plurality of annular shim members encircling each of said bushings, said shims in conjunction with said flanges filling the spaces between said shoulders and said retaining means and means operable to effect vertical reciprocation of said lift bar to move said valves into and out of engagement with said seats.