Shown here is a close-up of a Rotork CMA actuator installed on a ‘one day install’ (ODI) wellhead gas/water separator skid bound for the giant Queensland coal seam gas-to-LNG (Liquefied Natural Gas) project in Australia.
These remotely sited wellhead separators are designed to operate under a wide range of conditions. They include an automated control system with instrumentation and communication/telemetry to a central control room to enable operator assisted start up, shut down and monitoring.
Traditional skid designs take an average of two weeks to commission but, as the name suggests, the operator believes that, once delivered to site, the ODI skid can be operational within a day. The ODI design has attracted a lot of attention from all the major players in the Australian LNG industry.
Previously, produced gas was used as the operating medium for the actuators, but in some areas this is not feasible, so the operator searched for an economical and reliable electric alternative, capable of operating in remote areas from renewable power sources.
Fulfilling this requirement, the CMA actuator is available in linear, part-turn and multi-turn versions and a range of compact sizes. They facilitate 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. Continuous and unrestricted modulating performance is provided by a brushless DC motor and magnetic contactless sensors.
Accepting an industry-standard 4 -20mA command signal, the CMA delivers accurate and repeatable positional control. Resolution is 0.25% on linear and part-turn applications and 2 degrees on the multi-turn configuration.
