| 摘要 |
PURPOSE:To prevent the breakage of other valve parts by allowing a yoke sleeve or yoke bush which can be replaced most easily when an excessive operating torque is applied, to be broken. CONSTITUTION:A collar part 21 is formed at the lower-edge part of a yoke sleeve 20, and a yoke 23 can be revolved by pressing the collar part of the sleeve 20 by a sleeve press 22, and the yoke 23 is installed so as not to permit the vertical movement. A necessary radius R of curvature is provided for the root part 24 of the collar part 21, and a step difference 25 having an acute angle is installed onto the inner-diameter part of the collar part 21, biting to the collar part 21. When the valve is to be opened by applying an excessive torque onto a handle wheel 27, the yoke sleeve 20 tends to pull-up a stem 26, and the yoke sleeve 20 is shear-broken at the B part. |
