Abstract: A lubricant fitting (10) for connection to a valve (V) in which the fitting bore (20) has a pair of spaced apart inner (44) and outer (26) annular shoulders therein. A pair of spaced apart inner (52) and outer (54) seating elements are positioned within the bore (20) for movement between a normal seated position and an unseated position relative to their respective shoulders (44, 26) to thereby either prevent or allow communication between the valve interior and the atmosphere. The outer seating element (54) moves to the seated position independently of the inner seating element (52) so that even if the inner seating element (52) is sufficiently contaminated so that an effective seal cannot be formed, the outer seating element (54) will still move to form an effective seal and thereby isolate the valve interior from the atmosphere.

Abstract: In an expanding gate valve, tangential pins (70) are received loosely in peripheral grooves (62) of floating valve seats (26) to prevent the seats from moving inwardly far enough to drag against a gate mechanism (32) which is collapsed for movement between open and closed positions of the valve. Alternative arrangements provide retainer rings (122, 130) which engage shoulders (128) of the seats to limit their inward floating movement.

Abstract: In an expanding gate valve, tangential pins (70) are received loosely in peripheral grooves (62) of floating valve seats (26) to prevent the seats from moving inwardly far enough to drag against a gate mechanism (32) which is collapsed for movement between open and closed positions of the valve. Alternative arrangements provide retainer rings (122, 130) which engage shoulders (128) of the seats to limit their inward floating movement.