Abstract: A gate valve unit is provided for controlling the flow of a fluid through a conduit. The gate valve unit includes a valve body including a conduit connector member or flange. A valve face block affixed to the valve body includes first and second backwardly sloped surfaces. A pair of movable gate leaves are disposed on the first and second surfaces of the face block and are movable away from and toward a central passage through the unit for controlling fluid flow through the unit. A face seal provides a seal between the surfaces of the face block and the gate leaves. A visor seal is attached to the valve body which is movable between an operative position in which the visor seal provides sealing between the gate leaves, and an inoperable position away from the gate leaves so as to not interfere with the operation of the gate leaves.

Abstract: A gate valve unit is provided for controlling the flow of a liquid through a conduit. The gate valve unit includes a valve body including a conduit connector member or flange. A valve face block affixed to the valve body includes first and second backwardly sloped surfaces. A pair of movable gate leaves are disposed on the first and second surfaces of the face block and are movable away from and toward a central passage through the unit for controlling fluid flow through the unit. A face seal provides a seal between the surfaces of the face block and the gate leaves. A visor seal is attached to the valve body which is movable between an operative position in which the visor seal provides sealing between the gate leaves, and an inoperable position away from the gate leaves so as to not interfere with the operation of the gate leaves.