| 摘要 |
A bellows valve has inlet and outlet passages in fluid communication with a valve chamber on opposite sides of a valve seat. An elongated valve stem has a first end adapted for selective sealing engagement with the valve seat, and a second end of the stem is operatively connected with an actuator assembly. An expansible bellows has a first end secured to the valve stem and a second end sealingly connected to a closing member so that a portion of the valve stem is surrounded thereby. The closing member engages an open end of the valve body and includes an arcuate or rounded sealing protrusion or bead adapted for mating, sealing contact with a generally planar surface on the valve body. The sealing bead facilitates a reduction in or complete elimination of the use of lubricant between the valve body and a bonnet nut, and this, in turn, promotes clean valve operation by removing a potential contaminant. A tapered surface on the closing member faciitates alignment with the valve body, and clearances between the closing member, valve bonnet, and bonnet nut also facilitate alignment of the assembled valve components.
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