Abstract: [Problem] To provide a piston-format working-fluid-pressure actuator capable of commonly using components when the piston-format working-fluid-pressure actuator is used for a reverse action or a normal action and decreasing a length dimension, in the forward/backward movement direction of the output shaft and to provide a control valve using the piston-format working-fluid-pressure actuator and a valve member. [Solution] A piston-format working-fluid-pressure actuator (10) includes a casing (30) provided with a cylinder chamber (33) by including a cover portion (31) and a body portion (32), an output shaft (40) supported by the casing so as to be movable forward or backward, a piston (50) attached to the output shaft and defining the cylinder chamber, a spring member (60) applying an elastic force of moving the output shaft to the piston, and a working-fluid supply opening (70) supplying a working fluid.

Abstract: A seat ring has an insert for a butterfly valve configured so that an annular insert is fitted on the outer peripheral surface of the seat part in which there is provided a valve body fitting annular groove having side wall parts on both the upstream side and downstream side, wherein there are provided on the outer peripheral surface of the insert a step so that the outer diameter on the downstream side is smaller than the outer diameter on the upstream side and on the inner peripheral surface a locking projection, and the insert is fitted in an annular groove provided in the valve body fitting annular groove of the seat part.

Abstract: The present invention provides a seat ring with insert for a butterfly valve enabling improved valve seat sealing performance, valve stem sealing performance, and flange surface sealing performance, and enabling the easy and secure alignment of a valve stem in the manufacture of the seat ring and in the assembly of a valve body, and a method for manufacturing the same. A seat ring with insert for a butterfly valve configured so that an annular insert is fitted on the outer peripheral surface of the seat part in which there is provided a valve body fitting annular groove having side wall parts on both the upstream side and downstream side, wherein there are provided on the outer peripheral surface of the insert a step so that the outer diameter on the downstream side is smaller than the outer diameter on the upstream side and on the inner peripheral surface a locking projection, and the insert is fitted in the annular groove provided in the valve body fitting annular groove of the seat part.

Abstract: A butterfly valve includes a valve housing (1) having a substantially cylindrical flow passage formed therein, a disc-shaped valve element (4) arranged in the flow passage so as to be rotatable therein, a stem (3) extending from the valve element (4) to its outside and supported by the valve housing (1) so as to be rotatable, and an operating unit (8) for rotating the stem (3). The rotation of the stem (3) rotates the valve element (4) in the flow passage to open and close the flow passage. A top flange (2) for mounting the operating unit (8) is formed integrally with the valve housing (1). The top flange is formed with a plurality of cutouts (12) extending from the outer peripheral edge of the top flange toward the center thereof.