Abstract: A gate value having a sealing plate carried by a moveable element which through the coaction of a series of balls presses the sealing plate into a flow preventing position.

Abstract: A valve comprising: a housing having an opening therethrough around which is provided a seat; a closure assembly for blocking flow through the opening and for sealing engagement with the seat; and an actuator assembly connected to the closure assembly for moving the closure assembly between a first position, out of the flow path of the opening, to a second position, in the flow path, and for expanding the closure assembly for sealing engagement with the seat.

Abstract: Gate valve having a closure member mounted on a swinging arm pivotally mounted for movement transversely of the axis of the valve openings. A wedge member carried by the arm drives the closure member in a direction parallel to the axis of the openings when moved longitudinally of the arm. An actuator pivots a cam which bears against the wedge member to swing the arm to a predetermined position in which the closure member is aligned with the openings and thereafter to move the cam to drive the closure member axially and seal one of the openings. Resilient members urge the closure member toward its retracted position and prevent the wedge member from moving forward until the arm reaches the predetermined position.