Spring Return operators are formed by bolting a spring return unit to a double acting Val-U-Act operator. The return movement is effected by a clock-type spring which is pre-tensioned to about half the operator torque. The amount of pretension is large, compared to the rotation and therefore the torque does not vary more than 20% over the rotation.
Spring returns are factory-installed and adjusted and have a worm drive adjustment for setting or changing spring pretension. By inserting a socket key into one end of the worm the spring pretension can be very easily increased or decreased to suit operating conditions. To increase pretension, turn the worm clockwise; to decrease, turn counterclockwise.
| Compact Automation | |
|---|---|
| Product Category | Pneumatic Valve Actuators |
| Product Number | Model 822 |
| Product Name | Spring Return Ball Valve Operator |
| Valve Motion | Rotary |
| Operation | OnOff |
| Actuator Torque | 350 In-lbs (404 kg-cm) |
| Full Range of Rotary Motion | 90° |