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.
|Product Category||Pneumatic Valve Actuators|
|Product Number||Model 742|
|Product Name||Class-Act (CL) Valve Operator|
|Operating Temperature||-20 to 180 F (-28.89 to 82.22 C)|
|Full Range of Rotary Motion||90°|
|Acting type||Double Acting|