Abstract: A valve is described, with at least one annular valve seat element (15; 22), with a spindle (26) and with a closing part (25) which is connected to the latter and the center point of which lies in the axis of the spindle (26). The closing part (25) can be brought onto the valve seat (14; 21) as a result of the axial displacement of the spindle (26). The closing part (25) and the valve seat element (15; 22) can, in the preassembled state, be adjusted relative to one another into a fitted closed position in the manner of a ball movement and/or of a radial and axial movement and, in the ready-assembled state, are fixed in this fitted closed position.

Abstract: A valve apparatus for controlling a pressured fluid, in which the shut-off device is force closed by the pressured fluid which is admitted into a chamber via a throttle bore. The valve is opened via a drive means, which acts directly on both a pilot valve and on the shut-off device, without the interposition of an actuating fluid. The drive means first opens a pilot valve, thereby allowing the pressured fluid to escape from the chamber and to the outlet. The drive means then opens the shut-off device. The reduction in pressure in the chamber enables a drive means of only moderate power to complete the second step of opening the shut-off device. The drive means acts directly on the shut-off device; thus the control action corresponds directly to the stroke displacement of the drive means at any particular moment.