Fail Safe Actuators
Fail Safe Actuator is for larger valves with higher torque requirements, requiring reliable fail safe operation utilising a unique in-built air reservoir giving fail safe action without the torque losses inherent of spring designs.By using the time proven air accumulator system, and modern design techniques, produces air chamber modules with all the pneumatic circuitry safety protected within.
Fail safe actuators maintains the highest seen air supply pressure within the chamber modules, to be released upon control demand. This design also prevents closure creeping when air supply pressures drop, which occurs with all spring return designs. Torque output is constant in the powered stroke with only a small drop off on the fail stoke. The available torques are proportional to the air supply pressure. Spring changes for various air supply pressures need not be made.
The fail safe actuator operates as a double acting actuator in both directions until there is a loss of supply pressure. When this loss occurs, the compressed air stored in the chambers powers the actuator to close the valve. This makes the fail safe actuator series suitable for use in ON/OFF and modulating control situations while still providing the fail safe requirement.
Applications
- Wellhead
- Flowline
- Header
- Pipeline system
- Casing relief blowdown valve.