ABB RSD20 Electrical linear actuator, V68642-12-12-278-349 Rated force 20 kN (4500 lbf).Compact actuator for the operation of final control elements with rotary movement such as valve flaps, ball valves, etc. The torque is transferred via a lever-type actuator or the actuator is directly coupled to the shaft of the final control element. The actuator is controlled using a Contrac electronic unit. This electronic unit serves as the interface between the actuator and the control system. During continuous positioning, the electronic unit varies the motor torque steplessly until the actuator force and the control valve force are balanced. High response sensitivity and high positioning accuracy with short positioning time ensure an excellent control quality and a long actuator life.