Abstract: A two-piece retainer ring fits within opposed grooves (80,82) in a gate valve seat (64) and the adjacent valve body (12). The opposed grooves are of a width greater than the width of the two ring segments (84) comprising the two-piece ring and limit the movement of the associated floating seat (64). A wave spring (86) urges the ring segments (84) radially outwardly in the grooves and an access opening (88) to the grooves permits the ring segments (84) to be actuated by a suitable tool for removal of the seat, if desired.

Abstract: A double acting valve seat assembly which includes an annular outer seat member with an annular groove around a face portion thereof and an inner seat member mounted in the annular groove. A peripheral seal around the outer seat member seals in a bottom portion of the body recesses. A peripheral seal around the inner seat member seals in the groove. A face seal on the inner seat member seals against the valve member. The position of the seals is selected such that when the flow line pressure is greater than the valve chamber pressure the seat members are urged toward the valve member, and when the valve chamber pressure is greater than the flow line pressure the seat members are urged apart with the inner seat member being urged toward the valve member and the outer seat member being urged into a bottom portion of the associated recess.