Abstract: A pin-fastening structure includes a first shaft portion provided in a valve shaft; a cylindrical portion into which the first shaft portion is fitted, the cylindrical portion being provided in a valve body; and a connecting pin that passes through both the first shaft portion and the cylindrical portion in a state in which the first shaft portion is fitted into the cylindrical portion and that restricts relative movement of the first shaft portion and the cylindrical portion in an axial direction. The first shaft portion has a first end surface perpendicular to the axis of the valve shaft. The cylindrical portion has second end surfaces perpendicular to the axis of the valve body. The first shaft portion and the cylindrical portion are fastened by the connecting pin in a state in which the first end surface and the second end surfaces are in contact with each other.

Abstract: A pin-fastening structure includes a first shaft portion provided in a valve shaft; a cylindrical portion into which the first shaft portion is fitted, the cylindrical portion being provided in a valve body; and a connecting pin that passes through both the first shaft portion and the cylindrical portion in a state in which the first shaft portion is fitted into the cylindrical portion and that restricts relative movement of the first shaft portion and the cylindrical portion in an axial direction. The first shaft portion has a first end surface perpendicular to the axis of the valve shaft. The cylindrical portion has second end surfaces perpendicular to the axis of the valve body. The first shaft portion and the cylindrical portion are fastened by the connecting pin in a state in which the first end surface and the second end surfaces are in contact with each other.

Abstract: To obtain, even in a non-turbulent state, a capacity coefficient substantially the same as in a turbulent state, the downstream end of a wall surface of a flow rate characteristic window is the narrowest part in a flow channel of a valve main body and a through flow channel of a ball valve body and the wall surface of the flow channel between the narrowest part and the upstream end of the wall surface of the flow rate characteristic window is formed as a tapered surface tapered toward the smallest diameter part so that the flow channel is widened suddenly from the narrowest part of the flow rate characteristic window to the through flow channel.