MASCOT spring cylinder rotary actuator is a powerful, high-torque and high-stiffness pneumatic actuator, which can be used for precise throttling or on-off applications. Uniquely designed compact sized cylinders actuators accept supply pressures up to 150 psi, making very high torque available in a relatively compact unit making it the first choice for MASCOT control valves like the DiskFlo high performance butterfly valve, VFlo Segmented Ball Valve and the EFlo Eccentric Plug Valve. The MASCOT rotary actuator uses a “rocking” piston assembly for direct conversion of linear motion to rotary motion. The rocking piston assembly along with a splined shaft and lever eliminates any lost motion due to backlash.