For torque requirement valves up to 28500 inch.lbs (3220 Nm.) The AFS (Air Fail Safe) actuator is designed to provide a high fail stroke torque in a double rack and pinion actuator that cannot be achieved using springs. All the safety and performance features of double rack and pinion actuators are maintained as is the Hytork "XL" reliability.

Using the time proven air accumulator system, and modern design techniques, Hytork produces air chamber modules with all the pneumatic circuitry Safety protected within.

The HYTORK AFS 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 AFS 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 AFS Series suitable for use in ON/OFF and MODULATING CONTROL situations while still providing the fail safe requirement. The AFS is supplied already furnished with an installed, direct mount solenoid valve. The coil type is selected to suit your site requirements. This saves on site piping and ensures the assembly has been fully tested. Click here for information on Hytork's Fail Safe & Safety Spring Removal System.

Related Documentation:

• Technical Information
• Maintenance Manual
• PDF brochure for the Air Fail Safe Actuator

Actuator Features & Benefits:

• High Performance In The Fail And Powered Strokes
• High Reliability
• Compact Heavy Duty Design
• 4580AFS Actuator Torque At Various Air Pressures
• Diagrams & Charts
• Materials Of Construction