Abstract: A valve body unit is configured to be disengaged from a stem by moving the stem and the valve body unit to a valve seat side in a state where a bonnet is separated from the valve seat, thereby pushing a replacement ring such that the replacement ring moves through the bonnet while decreasing in diameter and then drops down onto a ring dropping portion in the free state, then moving the stem, the valve body unit, and the replacement ring to an opposite side to the valve seat side such that a first surface comes into contact with a second surface and the ring dropping portion comes into contact with the replacement ring, and in this state, moving only the stem to the opposite side to the valve seat side such that the connection formed by a connecting mechanism between the stem connection portion and the stem is released.

Abstract: An actuator includes a casing having a first annular groove formed in an inner peripheral portion thereof; a piston having a second annular groove formed in an outer peripheral portion thereof, provided in the casing to form a pressure chamber together with the casing, and driven by a drive fluid from an outside of the actuator; and an annular seal member having a first fitting portion to be fitted into the first annular groove and a second fitting portion to be fitted into the second annular groove to seal the pressure chamber.

Abstract: A first lever portion includes a first point-of-effort portion, a first fulcrum portion, and a first point-of-load portion. A second lever portion has a second point-of-effort portion, a second fulcrum portion, and a second point-of-load portion. A first point-of-effort portion is located between a first fulcrum portion and a first point-of-load portion in a direction orthogonal to an axis of a stem. A second fulcrum portion is located between a second point-of-effort portion and a second point-of-load portion in the direction orthogonal to the axis. A distance between the second fulcrum portion and the second point-of-load portion is configured longer than a distance between the second fulcrum portion and the second point-of-effort portion. The second point-of-load portion of the second lever portion is displaced toward the stem and moves the stem toward the piezoelectric element by means of displacement of the intermediate member to the second lever portion side.

Abstract: A bolt holding member is made of metal and holds a bolt in a fastened member. The bolt holding member includes: a main body portion that has a cylindrical shape; a first engaging piece that extends from the main body portion toward an inside of the main body portion at an incline relative to an axial direction of the main body portion; and a second engaging piece that extends from the main body portion toward an outside of the main body portion at an incline relative to the axial direction of the main body portion.

Abstract: A valve body unit is configured to be disengaged from a stem by moving the stem and the valve body unit to a valve seat side in a state where a bonnet is separated from the valve seat, thereby pushing a replacement ring such that the replacement ring moves through the bonnet while decreasing in diameter and then drops down onto a ring dropping portion in the free state, then moving the stem, the valve body unit, and the replacement ring to an opposite side to the valve seat side such that a first surface comes into contact with a second surface and the ring dropping portion comes into contact with the replacement ring, and in this state, moving only the stem to the opposite side to the valve seat side such that the connection formed by a connecting mechanism between the stem connection portion and the stem is released.

Abstract: A first lever portion includes a first point-of-effort portion, a first fulcrum portion, and a first point-of-load portion. A second lever portion has a second point-of-effort portion, a second fulcrum portion, and a second point-of-load portion. A first point-of-effort portion is located between a first fulcrum portion and a first point-of-load portion in a direction orthogonal to an axis of a stem. A second fulcrum portion is located between a second point-of-effort portion and a second point-of-load portion in the direction orthogonal to the axis. A distance between the second fulcrum portion and the second point-of-load portion is configured longer than a distance between the second fulcrum portion and the second point-of-effort portion. The second point-of-load portion of the second lever portion is displaced toward the stem and moves the stem toward the piezoelectric element by means of displacement of the intermediate member to the second lever portion side.

Abstract: An actuator includes: a casing; a pressure reducing valve and a piston. The pressure reducing valve is provided in the casing to reduce a pressure of a driving fluid supplied from an outside of the casing to a predetermined level. The piston is provided in the casing to form a pressure chamber together with the casing. The piston is driven by the driving fluid that has been pressure-reduced to the predetermined level.

Abstract: A valve device includes a valve body that defines flow paths, a diaphragm provided so as to be capable of opening and closing the flow paths, an operation member provided so as to be capable of moving in opening and closing directions that open and close the flow paths by operating the diaphragm, a main actuator that applies a driving force corresponding to an operating pressure applied in the opening direction or the closing direction of the opening and closing directions with respect to the operation member, a switching mechanism capable of selectively switching a position of the operation member that regulates a degree of opening of the flow paths between a first open position and a second open position in accordance with a magnitude of the operating pressure, and regulating mechanisms capable of independently regulating the first open position and the second open position.

Abstract: A valve device includes a valve body that defines flow paths, a diaphragm provided so as to be capable of opening and closing the flow paths, an operation member provided so as to be capable of moving in opening and closing directions that open and close the flow paths by operating the diaphragm, a main actuator that applies a driving force corresponding to an operating pressure applied in the opening direction or the closing direction of the opening and closing directions with respect to the operation member, a switching mechanism capable of selectively switching a position of the operation member that regulates a degree of opening of the flow paths between a first open position and a second open position in accordance with a magnitude of the operating pressure, and regulating mechanisms capable of independently regulating the first open position and the second open position.

Abstract: An actuator includes a casing having a first annular groove formed in an inner peripheral portion thereof; a piston having a second annular groove formed in an outer peripheral portion thereof, provided in the casing to form a pressure chamber together with the casing, and driven by a drive fluid from an outside of the actuator; and an annular seal member having a first fitting portion to be fitted into the first annular groove and a second fitting portion to be fitted into the second annular groove to seal the pressure chamber.

Abstract: An actuator includes: a casing; a pressure reducing valve and a piston. The pressure reducing valve is provided in the casing to reduce a pressure of a driving fluid supplied from an outside of the casing to a predetermined level. The piston is provided in the casing to form a pressure chamber together with the casing. The piston is driven by the driving fluid that has been pressure-reduced to the predetermined level.