Abstract: A valve apparatus for preventing the reverse of a thrust force and the generation of oscillation by smoothing a fluid flowing, including: an upper plug and an upper sheet ring which are for adjusting flow of fluid to an upper current path; and a lower plug and a lower sheet ring which are provided on the same axis as the upper plug and the upper sheet ring, and are for adjusting flow of fluid to a lower current path, wherein the generation of oscillation noise can be prevented by making the upper flowing path and the lower flowing path as different shapes, by making the upper and lower plug shape different, by making the plug operation stable with the reverse of the thrust force being prevented by making the fluid amount for the upper flowing path being increased, with the upper and lower sheet ring being formed as one body.

Abstract: A valve device includes a valve stem 2 vertically movably inserted in a packing box 1a; a gland packing 6 interposed between the packing box 1a and the valve stem 2; a packing follower 15 disposed on the gland packing 6; and one or more arched plate springs 19 for pressing the gland packing 6 via the packing follower 15 or a packing flange 7 disposed on the packing follower 15.

Abstract: A valve having a flow path in the form of a Venturi tube having a throttle and flow path sections extending and flaring from the opposite sides of the throttle to an inlet and outlet, respectively, and a cylindrical valve plug provided at the throttle and selectively movable at right angles to the flow path to present a flow path end into the flow path and having a semi-spherical valve head at the flow path end with a notch having a length in the direction of movement of the valve plug less than the diameter of the throttle formed in a portion of the valve head and the remaining portion of the valve head containing a diametrical line connecting opposite portions of the valve head in contact with the wall of the throttle while occupying a major portion of the surface of the valve head facing a flow in the flow path.