Innovative Approach to Add Manual Failsafe Handles for Large Quarter-Turn Valves

Kinetrol manual failsafe unit

Let's assume you have an application where it's critical that a large, pneumatically actuated valve cannot be left unattended in the wrong position (opened or closed). Or maybe your application requires the use of a manual operator with a fire-safe fusible link. The problem though, is the valve you want to control has torque requirements much greater than the output of any manual failsafe unit can provide. 

Here's an innovate and effective way to incorporate a manual failsafe unit on large size ball, butterfly, or plug valves. 

Retrofit your large valve with a 3-way "L" port ball valve and a manual failsafe spring handle on the large valve actuator's inlet air supply port. 

This allows the opening of the valve with the manual failsafe handle. When the handle is released, the valve shuts automatically by venting the air to atmosphere, and allowing the springs in the actuator to close the valve. 

Size limitations on the valves are no longer an issue, and this will work on anyone's pneumatic spring return actuator (spring return required, will not work on double acting actuators). 

Manual Override for Larger Valves