Rotork Process Controls (www.rotork.com) has extended the scope of its proven technology with the addition of the CMA (Compact Modulating Actuator), a new range of reliable and robust electric actuators for regulators, control valves and other continuous modulating applications.

Available in quarter-turn, linear and multi-turn versions, the compact actuators also extends the benefits provided by the Rotork CVA electric control valve actuator range and facilitates the economical operation of various types of damper, control valve and pump stroke adjuster applications. Control valve actuation requires a single-phase or DC electrical power supply to effectively save on-going costs related to the maintenance and operation of instrument air supplies.

Permanently lubricated, the maintenance-free CMA drive train is protected in an IP67 explosion proof, watertight enclosure and can be mounted in any position. The CMA provides repeatable and accurate positional control as it accepts an industry-standard command signal of four to 20mA. Resolution is two degrees on multi-turn applications and 0.25 percent on quarter-turn and linear configurations.

Unrestricted and continuous modulating performance is attributed to magnetic contactless sensors, a brushless DC motor and a lubricated drive train.

Meanwhile, actuator configuration is achieved through a menu driven process that employs an LCD display window and pushbuttons. The CMA features user selectable adjustments for dead band, common signal type, zero and span, speed, loss of signal position and standard or reverse action.

With manual operation as standard, optional extras include selector switch and local pushbuttons, digital position indicator and digital communication connectivity with Profibus, Foundation Fieldbus and HART.