Sunday, November 17, 2013

Fire-Safe Scotch-Yoke Actuators with 3 Second Operation

ROTEX Scotch Yoke
Critical Service Valves with
ROTEX DRS Scotch Yoke
A Central American power generation company needed 10" and 16", Class 900, triple-offset, critical service butterfly valves to operate flawlessly and quickly in the event of fire or loss of air supply.  They chose ROTEX Controls double acting DRS Scotch-Yoke actuators with hydraulic overrides.

The actuator package also specified a (5) second or less close time, a fusable link for emergency close in the event of fire, a declutchable manual override, and ASME air receiver tanks for "fail mode" that would allow for (2) full operational cycles.

ROTEX Controls engineers also included a 3-way fusable link that supplied air to a pilot operated shuttle valve. If the system was exposed to fire, the fusible link will fail, venting the air feed to the pilot causing the shuttle valve to shift and energize the actuator.

The result was an actuator that closed the valve in under (3) seconds. Additionally, the automated packages were delivered on time and under budget!