Gate valve with loosely retained rod seal

Claim 1

In a gate valve, a valve body having end and sidewalls, the end walls having openings forming flow passages, a gate within the body and movable between open and closed operating positions, a flange secured to one end of the body, a bonnet assembly mounted on said flange and including two platelike parts, an operating rod extending through the bonnet assembly and having its inner end connected to the gate, and self-aligning means within the bonnet assembly to prevent leakage of fluid pressure about the rod, said means comprising a rigid annular member having a central opening to accommodate the rod, the platelike members of the bonnet assembly being formed to loosely surround and retain said annular member for self-aligning movements and forming means for retaining the annular member against movement in the direction of the axis of the rod, sealing means forming a fluid pressure seal to prevent leakage between the annular member and the platelike bonnet parts, and sealing means forming a fluid pressure seal between the annular member and the operating rod, the retention of said annular member by said platelike parts permitting limited aligning movements of the annular member relative to the valve body.