Rotork has launched a new electric actuator for the operation of process control valves. The Rotork CVA range provides continuous, repeatable modulating control with a programmable fail to position option. Operating on an industry-standard 4-20mA control signal or digital bus, the resolution, repeatability and hysteresis performance of the CVA is quoted at <0.1% of full scale, making it suitable for the most demanding applications. The valve is available for the direct-drive actuation of linear or quarter-turn control valves. Mechanical features include Rotork’s well-known “double-sealed” enclosure, whereby internal electrical components are permanently protected from the effects of the operating atmosphere. The IP68 dust tight, watertight and temporarily submersible (7m, 72hrs) enclosure is universal to all models in the CVA range, including those with hazardous area approvals. The CVA is engineered to deliver high precision valve positioning and facilitate the tightest possible tolerances on the process variable, enabling process quality and output to be optimised. On loss of mains power, built-in super-capacitors allow the CVA to move the valve to a desired position, programmable as open, close, any intermediate position or stay-put. Manual operation is also optionally available.
