Manual Hold Open Devices are used to manually operate the valve
when control pressure is not available.
They thread directly to the top of the actuator and are used with 3Ó valves or smaller to 10,000 psi.
These devices are not intended to be left on the actuator for extended periods of time.
Three types of Manual Hold Open Devices are offered:
¥ Manual Hold Open Device -- Rotating handwheel produces sufficient
torque to overcome actuator spring force to open the valve.
¥ Manual Hold Open Device with Limit Switches -- This design
provides upper and lower limit switches to provide position
indication and SSV status. The limit switches are adjustable for
valve strokes up to 3Ó.
¥ Fusible Manual Hold Open Device -- This version includes a
fusible plug for protection under catastrophic conditions. This
device provides additional safety shutdown protection during