Abstract: A valve includes a device for shutting off a valve interior. The shutoff device is positioned by a piston which is guided in a cylinder and forms a first chamber and a second chamber in the cylinder. The second chamber communicates with the valve interior through a throttle path, so that the shutoff device is movable in a damped manner in both closing and opening directions.

Abstract: The invention relates to a pressure fitting (1) having a flow channel (42), a valve cone (5), a sliding element (43), and a locking device (12). The sliding element (43) is disposed displaceably along a main axis (41) of the pressure fitting (1). The valve cone is disposed on one end (44) of the sliding element (43). The flow channel (42) is closable by the valve cone (5) and the locking device (12) can be moved into a locking position, so that in a position of the valve cone (5) that opens the flow channel (42) the locking device (12) engages the valve cone (5) and/or the sliding element (42) and keeps the valve cone (5) in the position that opens the flow channel (42). Thereby a pressure relief in a pressurized system, in particular in a pressurizer (47) of a pressurized water reactor, can be assured even to a pressureless state. The pressure fitting is particular useful as a pressure relief valve or as a combined pressure relief and safety valve.