Abstract: A valve device includes a valve rod connecting a valve main body and a piston and capable of advancing and retracting in a first direction integrally with the valve main body and the piston, a rotary sleeve rotatably supported on a valve casing in a first circumferential direction around a first center axis, an operation member configured to rotate an operation shaft in a second circumferential direction, an advancing and retracting sleeve immovably fixed to the valve rod and the piston, and a stopper member configured to restrict an amount of movement of the advancing and retracting sleeve toward a first side in the first direction. The operation shaft is connected to the rotary sleeve such that a rotation of the operation shaft in the second circumferential direction can be converted into a rotation in the first circumferential direction and transmitted to the rotary sleeve.

Abstract: A manufacturing method of a casing, the manufacturing method includes a step of manufacturing a plurality of metal members which are components constituting the casing including a casing body having a tubular shape that extends with an axis as a center; a step of arranging the plurality of metal members according to the casing to be formed; and a step of forming the casing by welding the plurality of metal members to each other, in which in the step of manufacturing the metal members, the plurality of metal members are manufactured by at least two kinds of manufacturing methods among forging, steel plate processing, casting, and a fused metal deposition method.

Abstract: A manufacturing method of a casing, the manufacturing method includes a step of manufacturing a plurality of metal members which are components constituting the casing including a casing body having a tubular shape that extends with an axis as a center; a step of arranging the plurality of metal members according to the casing to be formed; and a step of forming the casing by welding the plurality of metal members to each other, in which in the step of manufacturing the metal members, the plurality of metal members are manufactured by at least two kinds of manufacturing methods among forging, steel plate processing, casting, and a fused metal deposition method.

Abstract: A stop valve includes: a valve seat in a fluid flow path; a valve disc that contacts the valve seat and that closes the fluid flow path; a valve stem that extends along a center axis includes a first end, in a direction of the center axis, that is connected to the valve disc; a spindle that extends along the center axis and comprises an end surface of a first end, in the direction of the center axis, that faces an end surface of a second end of the valve stem, in the direction of the center axis; and a connector that connects the second end of the valve stem to the first end of the spindle.

Abstract: A stop valve includes: a valve seat in a fluid flow path; a valve disc that contacts the valve seat and that closes the fluid flow path; a valve stem that extends along a center axis includes a first end, in a direction of the center axis, that is connected to the valve disc; a spindle that extends along the center axis and comprises an end surface of a first end, in the direction of the center axis, that faces an end surface of a second end of the valve stem, in the direction of the center axis; and a connector that connects the second end of the valve stem to the first end of the spindle.