Arrangement for actuating shut-off valve with tapered plug, has housing in which hollow actuating cylinder is coaxially supported for rotation and with an actuating shaft aligned with the coaxial axis firmly attached. Output cylinder is coaxially arranged in hollow actuating cylinder. The output cylinder is movable relative to hollow drive cylinder axially and radially. Spindle is attached on output cylinder opposite actuating shaft and aligned with coaxial axis; tapered plug being fastened on end of spindle facing away from output cylinder. At least one radially outwardly directed pin is arranged on outer peripheral surface of output cylinder. Outer surfaces of housing and hollow actuating cylinder have each at least one guideway extending over radial sector of outer surfaces, with which pin is operatively connected as a respective sliding block. At least the guideway arranged in outer surface of hollow actuating cylinder is formed as a through-opening through which pin passes.

An adjustable trunnion valve includes an obturator, a valve stem, at least one valve seal, and a trunnion. The trunnion and obturator are configured to translate the obturator along a longitudinal axis extending through the trunnion and the obturator upon rotation of the valve stem beyond one or both of its open position and its closed position. A method of operating an adjustable trunnion valve having an obturator coupled to a trunnion and a valve stem includes passing a fluid through the adjustable trunnion valve and rotating the valve stem to rotate the obturator about an axis of rotation and to simultaneously translate the obturator in a direction along the axis of rotation while the obturator is supported by the trunnion and while the fluid flows through the adjustable trunnion valve.

A valve device comprises a valve, housing, first and second seals. The valve includes a shaft, a rotor connected to the shaft in a first direction, and a first flow path having a first opening. The housing includes a space accommodating the valve, and a second flow path having a second opening in the space. The first seal is between an outer surface of the rotor and an inner surface of the space, and includes a first portion in the first direction and a second portion in a second direction. The second seal is in the second direction, and is between an outer surface of the valve and an inner surface of the space. The valve has a communication path connecting another space with the first flow path, the another space being surrounded by the outer surface of the valve, inner surface of the space, second portion, and second seal.

A valve device comprises a valve member, a housing, a first seal, and a second seal. The valve member includes a shaft portion rotatable about a rotation axis and a rotor connected to an end of the shaft portion in a first direction along the rotation axis, and, on an outer circumferential surface of the rotor there is a first flow path having a first opening. The housing includes an accommodating portion for accommodating the valve member, and a second flow path having a second opening communicable with the first opening, the accommodating portion having on its inner circumferential surface the second opening. A first seal is disposed between an outer circumferential surface of the rotor and an inner circumferential surface of the accommodating portion. The rotor includes a first region on which a coolant pressure acts in the first direction within the accommodating portion, and a second region on which the coolant pressure acts in a second direction opposite to the first direction, and a first area of the first region is below a second area of the second region.