Outside screw-and-yoke type valve

摘要

One or more grooves are provided to weaken a portion of the stem nut, retaining nut, or yoke bush in a disk/gate valve to provide selective breakage to limit axially directed forces transmittable through the stem and stem connection. Clearances between the valve body and the non-weakened nut or bush portion to permit axial movement of the latter relative to the former following breakage to provide visual indication of breakage.