CMA actuator increases scope of Rotork

Rotork Process Controls has launched a new range of compact, robust and reliable electric actuators for control valves, regulators and other continuous modulating applications. The CMA (Compact Modulating Actuator) extends the scope of Rotork’s proven technologies and the benefits inherent in the innovative Rotork CVA electric control valve actuator range.

The Rotork CMA is available in linear, quarter-turn and multi-turn versions and a range of five compact sizes, facilitating the economical operation of numerous types of control valve, damper and pump stroke adjuster applications. Single-phase or DC electrical power supply is all that is required for control valve actuation, saving the on-going costs associated with the operation and maintenance of instrument air supplies.

The maintenance-free CMA drive train, permanently lubricated and protected in an IP67 watertight and, where required, explosionproof enclosure, can be mounted in any orientation. Accepting an industry-standard 4 -20mA command signal, the CMA delivers accurate and repeatable positional control. Resolution is 0.25% on linear and quarter-turn applications and 2 degrees on the multi-turn configuration.

Continuous and unrestricted modulating performance is provided by a brushless DC motor, magnetic contactless sensors and an integral anti-backlash mechanism, preventing stick/slip and any unwanted movements resulting from fluctuating process pressure. Actuator configuration is performed in a logical, menu driven process using pushbuttons and an LCD display window. User selectable adjustments are provided for speed, dead band, zero and span, command signal type, standard or reverse action and loss of signal position.