Actuators cover all valve and damper applications

The new Exlar range of linear and rotary actuators is one of the most comprehensive available for the precise control and positioning of process valves and dampers.

The new Exlar range of linear and rotary actuators is one of the most comprehensive available for the precise control and positioning of process valves and dampers.

The new range incorporates features specially developed for use in process applications, such as digital positioning, explosion proof ratings, manual operation, stainless steel housings and suitability for operation in high ambient temperatures.

These features, combined with the wide choice of actuator types, enable the Exlar range to deliver simple and effective solutions for nearly every size of valve and damper in plants and installations both on and offshore.

The combination of Exlar's high power motor design and highly efficient mechanical torque convertor applies force to valves or dampers with the speed and accuracy necessary to achieve the quality and throughput required in today's competitive process environments.

A typical 150mm stroke Exlar actuator used in a valve application can control position accurately to +/-0.5% while ready to fully open or close in less than 200ms.

This kind of accuracy and response allows the user to benefit from system performance previously achievable only through the use of complex and expensive servo hydraulic valve positioning systems.

The Exlar actuators are completely self-contained, IP65 rated units, offering the facility for analogue or digital (closed loop) control, and programming of speed, thrust force and stroke via Exlar's all digital positioner unit.

Simple setup and diagnostics for these tasks is provided by Windows software, which is part of a positioner package that also offers the facility for system monitoring.

The range of actuators for use with the positioner unit includes four types: the SR/GS Series of linear actuators, the SLG Series of rotary actuators, SR/SLG series damper actuators and the FT Series for large valves and dampers.

Both the SR and GS Series linear actuators are based upon a unique design, integrating a robust and efficient threaded roller mechanism into the centre of a high power density, high performance brushless servomotor.

This combination results in an all-electric actuator which is extremely compact, yet delivers similar performance to a hydraulic cylinder in terms of force, resistance to shock and extended service life.

The SR/GS Series actuators are designed for all type of valve actuations from turbine- powered generators to pumps controlling the flow of petroleum on offshore oilrigs.

They are available in both conventional and explosion proof designs allowing the process engineer to make Exlar actuators the plant standard for valve actuation.

The SLG Series of closed-loop, servo controlled rotary actuators are ideal for operating quarter-turn, full-turn or multi-turn valves or shaft driven dampers.

In shaft driven loads, Exlar's rotary actuators are directly coupled shaft-to-shaft.

This eliminates the ungainly mechanisms usually necessary to convert the linear motion of pneumatic and hydraulic cylinders to rotational motion.

The SLG series offers a wide operating speed range from 0.01 to 1250rev/min and provides maximum torque up to 327Nm.

Exlar's SR and SLG, linear and rotary actuators, are particularly well suited for use in operating industrial dampers.

Their unique, compact design makes them generally immune to environmental issues such as heat or corrosion.

Offering the facility for both analogue (4-20mA) and digital control (over 20,000 increments per 25mm), the actuators are dimensionally similar to fluid power actuators, allowing direct substitution in many applications.

FT Series actuators are designed to operate very large valves, dampers and gates, which require longer strokes and higher thrusts than available with the GS or SR Series actuators.

The FT Series combines planetary roller screw operation with closed loop servomotor precision to provide force ratings up 18,180kg (peak) and speed ratings of up to 1.5m/s, over stroke lengths from 150mm right up to 2.5m.

Optimising the performance of the Exlar actuators in valve and damper applications is the SV2000 Series digital position controller.

The SV2000 is a highly robust electronic positioner, which operates in closed loop to ensure that each actuator's output corresponds exactly to the commands issued a system's DCS or PLC.

The combination of the SV2000 positioner and actuator responds to command signal changes in less than 5ms.

The speed of this response, combined with the dynamic capability of the all-electric actuator, delivers repeatability much greater than that available from typical pneumatic or hydraulic cylinders, together with extremely fast end-to-end travel times.

This performance makes Exlar's actuators the obvious choice for applications such as turbine and compressor controls and test stands where the valve reaction to process changes are critical and where repeatability directly affects the results of the process.

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