| 摘要 |
<p>The invention relates to a control and shut-off valve with a valve seat disc (6) of ceramic material held nonrotatably in the housing and having at least one throughflow opening (7) and with a ground seating surface against which a valve regulating disc (5), which is rotatable coaxially with the centre line, is likewise manufactured from ceramics material and has at least one throughflow opening (7), rests with a ground sealing surface, both discs having an all-round annular disc rim in the outer region of the throughflow openings. To improve the operation of the valve and, in particular, for smoothness of operation, it is proposed that the disc rim, which does not act as a sealing surface in the closed position, have one or more set back surface areas (8) at the sealing plane, in the region of the ground sealing surfaces of the valve regulating disc and/or the valve seating disc. <IMAGE></p> |
