How Bettis Scotch Yoke Actuators Work
Bettis Scotch Yoke Actuators operate using a mechanical linkage that converts linear motion into rotary motion—specifically designed for quarter-turn valve applications. The actuator uses air or hydraulic pressure to drive a piston forward or backward. This piston is connected to a specially designed yoke that engages with a central rotating shaft. As the piston moves, the yoke slides along a fixed pin on the shaft, causing the shaft to turn—typically 90 degrees—to open or close the valve.
The key advantage of the Scotch yoke mechanism is its ability to generate non-linear torque output, with the highest torque occurring at the beginning and end of the stroke. This torque profile matches the natural resistance of most valves, which require the most force during breakaway and final seating. Bettis actuators are precision-engineered to make the most of this design, offering reliable and powerful movement even under high-pressure or dirty service conditions.
In addition, Bettis actuators are modular, meaning they can be easily customized with control accessories like solenoid valves, positioners, and feedback switches. With safety and reliability at the forefront, these actuators also support fail-safe spring-return functionality, ensuring controlled shutdowns during power or signal loss. Whether for simple on/off duties or precise modulating control, Bettis Scotch Yoke Actuators deliver dependable performance across a broad range of industrial settings.
