Abstract: A gate valve apparatus is disclosed. The gate valve apparatus is provided with a valve casing that includes a first valve seat and a second valve seat, and in which an opening portion is formed; and a closure element that includes a sealing member that contacts the first valve seat to seal the opening portion. In addition, the gate valve apparatus is provided with a shutoff member that contacts the second valve seat to thereby be deformed, so that a space between the opening portion and a sealing member is shut off by the shutoff member when the closure element closes the opening portion. The shutoff member is deformed and continues to contact the second valve seat under normal and high temperature environments when the closure element closes the opening portion.

Abstract: Agate valve apparatus is disclosed. The gate valve apparatus is provided with a valve casing that includes a first valve seat and a second valve seat, and in which an opening portion is formed; and a closure element that includes a sealing member that contacts the first valve seat to seal the opening portion. In addition, the gate valve apparatus is provided with a shutoff member that contacts the second valve seat to thereby be deformed, so that a space between the opening portion and a sealing member is shut off by the shutoff member when the closure element closes the opening portion. The shutoff member is deformed and continues to contact the second valve seat under normal and high temperature environments when the closure element closes the opening portion.

Abstract: To provide a valve element unit and a gate valve apparatus which realize a reduction in manufacturing cost by a compact and simple structure and smooth rotary driving of the valve element without greatly moving the valve element in the direction of the center of rotation when the valve element is rotary driven. When a valve element unit 52 is rotary driven by valve element driving mechanisms 54, a rotary drive radius R2 of longitudinal both end sides of a first valve element 56 is smaller than a rotary drive radius R1 of a longitudinal center side of the first valve element 56.

Abstract: A valve device includes a valve element unit for closing or opening a first opening formed in a casing; a valve element driving unit for rotating the valve element unit around an axis to move to a position facing the first opening, and for moving the valve element unit in a radial direction to seat at the first opening; a first sealing member provided on the valve element unit; and a stopper for restricting a rotation of the valve element unit. The valve element driving unit includes a support for supporting the valve element unit to be rotatable; a shaft part having an eccentric shaft portion connected to the valve element unit and having a center located at a position apart from a rotational center by a predetermined distance; and a driving source for rotating the shaft part. The stopper restricts a rotation of the support in one direction at a position where the valve element unit faces the opening.

Abstract: To provide a valve element unit and a gate valve apparatus which realize a reduction in manufacturing cost by a compact and simple structure and smooth rotary driving of the valve element without greatly moving the valve element in the direction of the center of rotation when the valve element is rotary driven. When a valve element unit 52 is rotary driven by valve element driving mechanisms 54, a rotary drive radius R2 of longitudinal both end sides of a first valve element 56 is smaller than a rotary drive radius R1 of a longitudinal center side of the first valve element 56.