Bellows for sealing a valve rod passage in a globe valve

摘要

The invention relates to a bellows to seal a valve rod passage in a lifting valve, specifically formed as an expansion bellows or corrugated tube, which ensures a reliable, hygienically proper and durable static sealing of the connecting flange of a closing-member unit in the box of the lifting valve under the occurring forces at an adequately long service life. This is achieved by the fact that the connecting flange (40) of the closing-member unit (4), in the region where it is connected to the bellows (4b), has a fastening component (4f) indirectly supported on the box side to absorb, in a way free from bending moments to a very large extent, the forces resulting from the valve-lift induced deformation of the bellows (4b) and/or the respective pressure in the box (1a) and is reduced, in the area of its conical sealing surface (4h), to a minimal wall thickness meeting the strength-related requirements, in the form of a diaphragm-shaped sealing element (4l), and that the diaphragm-shaped sealing element (4l), on its side facing away from the conical scaling surface (4h) has at least one biased elastic thrust ring (5) which presses the sealing surface (4h) onto the complementary annular seating surface (1k).