| 摘要 |
A valve body has a stem passage rotatably receiving a valve stem. A packing surrounds the stem in the passage and a packing nut threaded on the stem applies axial force to radially expand the packing into sealing engagement with the stem and passage wall. The packing comprises cooperating first and second packing members engaging at an angularly disposed slippage surface for translation of compressive axial forces into radial expansion and sealing engagement with the stem and passage wall. A packing support ring engages the end face of the packing adjacent the packing nut. A gland engages the support ring and a pair of reversely positioned spring washers are interposed between the gland and packing nut. A handle is attached to the stem by a handle nut, and a spring washer interposed between the handle and handle nut prevents loosening of the handle nut. In an alternate embodiment of the invention, opposed packing support rings engage the opposed end faces of the first and second packing members. The support rings include chevron surfaces for radially expanding the packing members and the support ring adjacent the packing nut includes notches in the chevron surface for gripping the packing member to prevent relative sliding movement therebetween. |
