| 摘要 |
A valve for controlling the flow of bulk material has a housing (1 a, 1b) with a circular opening capable of being sealed by a cup member (2) rotatably mounted in the housing (1b). The peripheral rim area of the cup member (2) is sealed by seal discs (9a, 9b, 9c) movable by means of a fluid-actuated annular piston (11). To attain a secure lifting of the seal discs (8a, 9b, 9c) from the cup (2) prior to its swivelling from the closed into the open position, the seal discs (9a, 9b, 9c) are rigidly connected to the annular piston (11) which is driven itself by a pressure-chargeable cylinder having two elastic bellows (13, 14) located coaxially to each other and bearing axially against the piston. <IMAGE> |
