| 摘要 |
A bellows valve (A) has inlet and outlet passages (10,12) in fluid communication with a valve chamber (14) on opposite sides of a valve seat (18). A valve stem (C) has a first end (30) adapted for selective sealing engagement with the valve seat (18), and a second end (32) of the stem (C) is operatively connected with an actuator assembly (H). An expansible bellows (1) has a first end (40) secured to the valve stem (C) and a second end (42) sealingly connected to a closing member (E) so that a portion of the valve stem (C) is surrounded by the bellows. The closing member (E) engages an open end (16) of the valve body (B) and includes an annular or rounded sealing protrusion or bead (58) adapted for mating, sealing contact with a generally planar surface (60) on the valve body (B). The sealing bead (58) facilitates a reduction in or complete elimination of the use of lubricant between the valve body (B) and a bonnet nut (G), and this, in turn, promotes clean valve operation by removing a potential contaminant. A tapered surface (62) on the closing member (E) facilitates alignment with the valve body, and radial clearances between the closing member (E), valve bonnet (B), and bonnet nut (G) also facilitate alignment of the assembled valve components. |
