On a rising-stem manual valve, the yoke carries the yoke sleeve or stem nut that the handwheel turns, keeping the threads outside and away from the process. On a control valve, the actuator bolts to the yoke and the stem connector and travel indicator sit inside it. The open frame lets you see the stem and reach the gland nuts.
Bolt the positioner bracket to the yoke and get the feedback arm square to the stem at 50 percent travel.
Also heard as
- bonnet yoke
- yoke arm
Related terms
OS&Y
Outside screw and yoke: a rising-stem valve design with its stem threads above the packing, out of the fluid.
Bonnet
The cover that closes the top of a valve body and carries the stem, packing and often the yoke.
Stem
The rod that carries motion from the handwheel, lever or actuator through the bonnet to the closure member.
Actuator
The powered device that opens, closes or positions a valve using air, hydraulic oil or an electric motor.