{"id":11859,"date":"2026-10-21T02:21:15","date_gmt":"2026-10-21T02:21:15","guid":{"rendered":"https:\/\/www.fleyendavalve.com\/?p=11859"},"modified":"2026-10-21T02:21:15","modified_gmt":"2026-10-21T02:21:15","slug":"what-is-a-rotary-actuator-types-working-principle-selection-guide","status":"publish","type":"post","link":"https:\/\/www.fleyendavalve.com\/ru\/what-is-a-rotary-actuator-types-working-principle-selection-guide\/","title":{"rendered":"What Is a Rotary Actuator? Types, Working Principle & Selection Guide"},"content":{"rendered":"
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Rotary Actuator Guide<\/span><\/p>\n

What Is a Rotary Actuator? Types, Working Principle & Selection Guide<\/h1>\n

A rotary actuator is a device that produces rotational motion and torque to operate equipment such as ball valves, butterfly valves, plug valves and dampers. In industrial valve automation, rotary actuators are commonly used for quarter-turn movement, typically rotating the valve approximately 90\u00b0 between open and closed positions.<\/p>\n

Rotary actuators can be powered electrically, pneumatically or hydraulically. Electric rotary actuators are especially common where remote control, precise positioning, PLC integration and operation without a compressed-air system are required.<\/p>\n

Quick Answer:<\/strong> A rotary actuator converts electrical, pneumatic or hydraulic energy into rotational mechanical motion. For industrial valves, a quarter-turn rotary actuator usually rotates a valve stem between 0\u00b0 and 90\u00b0. Ball valves, butterfly valves and many plug valves are common rotary-actuated valve types.<\/div>\n<\/div>\n
\"\"<\/div>\n<\/section>\n
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Definition<\/span><\/p>\n

What Is a Rotary Actuator?<\/h2>\n

A rotary actuator is a mechanical drive device designed to create angular movement around an axis. Instead of producing straight-line motion like a linear actuator, it produces rotational output that can turn a shaft, stem, disc, ball or other rotating component.<\/p>\n

In industrial flow-control systems, the term rotary actuator commonly refers to an actuator mounted on a quarter-turn valve. The actuator applies torque to the valve stem and rotates the closure element into the required position.<\/p>\n

For example, a ball valve normally requires approximately 90 degrees of rotation between fully open and fully closed. A butterfly valve operates in a similar way: the actuator rotates the valve shaft, which changes the position of the internal disc.<\/p>\n

Rotary actuator technology is therefore widely used in automated piping systems where valves need to be opened, closed, positioned or controlled without direct manual operation.<\/p>\n

\"\"<\/p>\n<\/div>\n<\/section>\n

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Working Principle<\/span><\/p>\n

How Does a Rotary Actuator Work?<\/h2>\n

The operating principle depends on the actuator power source, but the basic objective is the same: generate enough torque to rotate the connected shaft through a defined angle.<\/p>\n

In an electric rotary actuator, an electric motor produces rotational motion. Because the motor normally operates at a higher speed and lower torque than the valve requires, a gear reduction system converts this motor output into slower movement with higher usable torque.<\/p>\n

The actuator output drive then transfers the torque to the valve stem. Internal limit switches, position sensors or electronic controls determine when the required travel position has been reached.<\/p>\n

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01<\/p>\n
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Control Command<\/h3>\n

A switch, PLC, DCS or control system sends an open, close or positioning signal to the actuator.<\/p>\n<\/div>\n<\/div>\n

02<\/p>\n
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Power Conversion<\/h3>\n

The electric motor, pneumatic mechanism or hydraulic system converts available energy into mechanical movement.<\/p>\n<\/div>\n<\/div>\n

03<\/p>\n
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Torque Generation<\/h3>\n

The actuator develops enough output torque to overcome valve seat friction, differential pressure and mechanical resistance.<\/p>\n<\/div>\n<\/div>\n

04<\/p>\n
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Rotary Movement<\/h3>\n

The actuator output shaft rotates the valve stem toward the required angular position.<\/p>\n<\/div>\n<\/div>\n

05<\/p>\n
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Position Confirmation<\/h3>\n

Limit switches, encoders or position sensors confirm when the required valve position has been reached.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

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Actuator Types<\/span><\/p>\n

Types of Rotary Actuators<\/h2>\n

Rotary actuators can be classified according to their power source and internal operating mechanism. The correct type depends on available utilities, required torque, operating speed, control accuracy and installation environment.<\/p>\n

Electric Rotary Actuator<\/h3>\n

An electric rotary actuator uses an electric motor and gear reduction system to produce rotational torque. It is widely used where electricity is readily available and remote or automatic valve control is required.<\/p>\n

Electric rotary actuators can support ON\/OFF control, modulating positioning, status feedback and communication with industrial automation systems.<\/p>\n

Pneumatic Rotary Actuator<\/h3>\n

A pneumatic rotary actuator uses compressed air to generate rotational motion. Rack-and-pinion and Scotch yoke designs are common in industrial valve automation.<\/p>\n

Pneumatic actuators are often selected where rapid cycling, simple spring-return fail-safe operation or integration with an existing compressed-air system is important.<\/p>\n

Hydraulic Rotary Actuator<\/h3>\n

Hydraulic rotary actuators use pressurized hydraulic fluid and are particularly useful when very high torque is required. They are commonly found in heavy-duty industrial equipment, energy infrastructure and specialized automation systems.<\/p>\n<\/div>\n<\/section>\n

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Motion Types<\/span><\/p>\n

Quarter-Turn vs Multi-Turn Actuators<\/h2>\n

One of the most important distinctions in valve automation is the difference between quarter-turn and multi-turn movement.<\/p>\n\n\n\n\n\n\n\n\n\n
\u041e\u0441\u043e\u0431\u0435\u043d\u043d\u043e\u0441\u0442\u044c<\/th>\nQuarter-Turn Rotary Actuator<\/th>\nMulti-Turn Actuator<\/th>\n<\/tr>\n<\/thead>\n
Typical Movement<\/strong><\/td>\nApproximately 0\u201390\u00b0<\/td>\nMultiple complete rotations<\/td>\n<\/tr>\n
Primary Output<\/strong><\/td>\nRotary torque<\/td>\nRotary torque that may also create linear stem movement<\/td>\n<\/tr>\n
Typical Valves<\/strong><\/td>\nBall valves, butterfly valves and plug valves<\/td>\nGate valves and globe valves<\/td>\n<\/tr>\n
Travel<\/strong><\/td>\nShort angular movement<\/td>\nMultiple shaft revolutions<\/td>\n<\/tr>\n
Common Applications<\/strong><\/td>\nWater treatment, HVAC, chemical processing and industrial automation<\/td>\nPower plants, steam systems, pipelines and large isolation valves<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

A rotary actuator is therefore not simply another name for every valve actuator. The term usually refers to equipment designed primarily for angular rotational movement, especially quarter-turn applications.<\/p>\n<\/div>\n<\/section>\n

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\u0421\u0442\u0440\u043e\u0438\u0442\u0435\u043b\u044c\u0441\u0442\u0432\u043e<\/span><\/p>\n

Main Components of an Electric Rotary Actuator<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n
\u041a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442<\/th>\n\u0424\u0443\u043d\u043a\u0446\u0438\u044f<\/th>\n\u041a\u0440\u0438\u0442\u0435\u0440\u0438\u0438 \u043e\u0442\u0431\u043e\u0440\u0430<\/th>\n<\/tr>\n<\/thead>\n
Electric Motor<\/strong><\/td>\nGenerates the initial rotational movement.<\/td>\nVoltage, thermal protection and operating duty.<\/td>\n<\/tr>\n
Gear Reduction<\/strong><\/td>\nReduces motor speed and increases usable output torque.<\/td>\nMechanical efficiency, durability and required torque.<\/td>\n<\/tr>\n
Output Drive<\/strong><\/td>\nTransfers actuator torque to the valve stem.<\/td>\nValve interface and mounting dimensions.<\/td>\n<\/tr>\n
Limit Switches<\/strong><\/td>\nDefine open and closed travel positions.<\/td>\nAdjustment range and feedback requirements.<\/td>\n<\/tr>\n
Torque Protection<\/strong><\/td>\nProtects the valve and actuator from excessive mechanical resistance.<\/td>\nAvailability and adjustment depend on actuator design.<\/td>\n<\/tr>\n
Position Indicator<\/strong><\/td>\nShows actuator or valve position.<\/td>\nLocal indication and remote feedback requirements.<\/td>\n<\/tr>\n
Manual Override<\/strong><\/td>\nAllows manual operation during commissioning or power failure.<\/td>\nAccessibility and operating method.<\/td>\n<\/tr>\n
Actuator Housing<\/strong><\/td>\nProtects internal electrical and mechanical components.<\/td>\nIP rating, corrosion resistance and hazardous-area requirements.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n
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Control Modes<\/span><\/p>\n

ON\/OFF, Modulating and Intelligent Rotary Actuators<\/h2>\n

Electric rotary actuators can provide different levels of control depending on the automation requirements of the process.<\/p>\n

ON\/OFF Rotary Actuator<\/h3>\n

An ON\/OFF rotary actuator moves the valve between two primary positions: fully open and fully closed. This configuration is commonly used for pipeline isolation, equipment shutoff, automatic switching and process interlocks.<\/p>\n

Modulating Rotary Actuator<\/h3>\n

A modulating rotary actuator positions the valve at intermediate angles rather than only at the end positions. Industrial electric actuators may receive analog control signals such as 4\u201320 mA or 0\u201310 V from a PLC, controller or process instrument.<\/p>\n

This allows valve position to change according to flow rate, pressure, temperature, liquid level or another process variable.<\/p>\n

Intelligent Rotary Actuator<\/h3>\n

Intelligent rotary actuators add electronic positioning, diagnostics, remote monitoring and communication functions. Depending on the actuator configuration, RS485, Modbus or other communication protocols can be used to exchange operating information with the control system.<\/p>\n

Important:<\/strong> Installing a modulating actuator does not automatically make every valve suitable for accurate throttling. The valve itself must have appropriate control characteristics. A V-port ball valve, for example, is generally more suitable for proportional flow control than a standard full-port ball valve.<\/div>\n<\/div>\n<\/section>\n
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\u0421\u0440\u0430\u0432\u043d\u0435\u043d\u0438\u0435<\/span><\/p>\n

Rotary Actuator vs Linear Actuator<\/h2>\n\n\n\n\n\n\n\n\n\n
\u0424\u0430\u043a\u0442\u043e\u0440<\/th>\nRotary Actuator<\/th>\nLinear Actuator<\/th>\n<\/tr>\n<\/thead>\n
Motion<\/strong><\/td>\nAngular or rotational movement<\/td>\nStraight-line movement<\/td>\n<\/tr>\n
Primary Output<\/strong><\/td>\nTorque<\/td>\nThrust or force<\/td>\n<\/tr>\n
Typical Valves<\/strong><\/td>\nBall, butterfly and plug valves<\/td>\nGlobe, diaphragm and other linear-stem valves<\/td>\n<\/tr>\n
Travel<\/strong><\/td>\nCommonly around 90\u00b0 for quarter-turn valves<\/td>\nMeasured as linear stroke<\/td>\n<\/tr>\n
Main Selection Parameter<\/strong><\/td>\nRequired torque<\/td>\nRequired thrust and stroke<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

This distinction is important because torque and thrust are different engineering parameters. A quarter-turn valve generally requires an actuator capable of delivering adequate rotational torque, while a linear-stem valve requires sufficient axial thrust.<\/p>\n<\/div>\n<\/section>\n

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\u0418\u0441\u0442\u043e\u0447\u043d\u0438\u043a \u043f\u0438\u0442\u0430\u043d\u0438\u044f<\/span><\/p>\n

Electric vs Pneumatic Rotary Actuator<\/h2>\n\n\n\n\n\n\n\n\n\n\n
\u0424\u0430\u043a\u0442\u043e\u0440<\/th>\nElectric Rotary Actuator<\/th>\nPneumatic Rotary Actuator<\/th>\n<\/tr>\n<\/thead>\n
\u0418\u0441\u0442\u043e\u0447\u043d\u0438\u043a \u043f\u0438\u0442\u0430\u043d\u0438\u044f<\/strong><\/td>\n\u042d\u043b\u0435\u043a\u0442\u0440\u043e\u044d\u043d\u0435\u0440\u0433\u0438\u044f<\/td>\nCompressed air<\/td>\n<\/tr>\n
Required Infrastructure<\/strong><\/td>\nElectrical wiring and controls<\/td>\nAir compressor, tubing and accessories<\/td>\n<\/tr>\n
Position Control<\/strong><\/td>\nElectronic positioning is readily available<\/td>\nUsually requires a pneumatic or electro-pneumatic positioner<\/td>\n<\/tr>\n
\u0420\u0430\u0431\u043e\u0447\u0430\u044f \u0441\u043a\u043e\u0440\u043e\u0441\u0442\u044c<\/strong><\/td>\nDepends on motor and gearbox configuration<\/td>\nOften relatively fast<\/td>\n<\/tr>\n
Fail-Safe Option<\/strong><\/td>\nRequires spring, capacitor, battery or other fail-safe design<\/td>\nSpring-return configurations are widely available<\/td>\n<\/tr>\n
\u0422\u0438\u043f\u0438\u0447\u043d\u044b\u0435 \u043e\u0431\u043b\u0430\u0441\u0442\u0438 \u043f\u0440\u0438\u043c\u0435\u043d\u0435\u043d\u0438\u044f<\/strong><\/td>\nRemote sites, water treatment, HVAC and automated equipment<\/td>\nChemical plants, frequent cycling and compressed-air facilities<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Neither technology is universally better. The correct choice depends on available plant utilities, operating frequency, required speed, failure strategy, maintenance capability and lifecycle cost.<\/p>\n<\/div>\n<\/section>\n

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Torque Selection<\/span><\/p>\n

How to Size a Rotary Actuator<\/h2>\n

Torque is one of the most important rotary actuator selection parameters. An actuator must provide sufficient output torque to operate the valve under actual process conditions rather than only under ideal conditions.<\/p>\n

The selection process normally starts with the valve manufacturer’s required breakaway, running or seating torque. Engineers should then consider the conditions that can increase torque during operation.<\/p>\n

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01<\/p>\n
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Valve Size<\/h3>\n

Larger valves generally require greater operating torque because the closure element, stem and sealing surfaces are larger.<\/p>\n<\/div>\n<\/div>\n

02<\/p>\n
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Differential Pressure<\/h3>\n

The pressure difference across a closed valve can significantly affect the torque required to start and complete valve movement.<\/p>\n<\/div>\n<\/div>\n

03<\/p>\n
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\u041c\u0430\u0442\u0435\u0440\u0438\u0430\u043b \u0441\u0438\u0434\u0435\u043d\u0438\u0439<\/h3>\n

Seat design and friction influence breakaway, running and seating torque.<\/p>\n<\/div>\n<\/div>\n

04<\/p>\n
\n

\u0420\u0430\u0431\u043e\u0447\u0430\u044f \u0441\u0440\u0435\u0434\u0430<\/h3>\n

Viscous liquids, suspended solids, deposits, crystallization and contamination can increase mechanical resistance.<\/p>\n<\/div>\n<\/div>\n

05<\/p>\n
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Operating Temperature<\/h3>\n

Temperature can affect seat characteristics, seals, lubrication and actuator output performance.<\/p>\n<\/div>\n<\/div>\n

06<\/p>\n
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Operating Frequency<\/h3>\n

Frequent cycling creates greater thermal and mechanical demand on the actuator than occasional isolation service.<\/p>\n<\/div>\n<\/div>\n<\/div>\n

A torque margin is normally used when matching a rotary actuator to a valve. However, there is no single percentage that should automatically be applied to every valve. The appropriate margin should be determined from valve torque data, actuator performance and actual process conditions.<\/p>\n<\/div>\n<\/section>\n

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\u0423\u0433\u043e\u043b \u043f\u043e\u0432\u043e\u0440\u043e\u0442\u0430<\/span><\/p>\n

What Rotation Angle Does a Rotary Actuator Need?<\/h2>\n

Most industrial ball valves and butterfly valves use approximately 90 degrees of travel. For this reason, the most common rotary valve actuator is a quarter-turn actuator that moves between approximately 0\u00b0 and 90\u00b0.<\/p>\n

Other equipment may require different angular travel. Dampers, diverter mechanisms and specialized valves can require 180\u00b0 rotation or another defined angle.<\/p>\n

The actuator travel should therefore match the actual valve or equipment requirement rather than assuming that every rotary actuator application requires exactly the same movement.<\/p>\n<\/div>\n<\/section>\n

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Environmental Protection<\/span><\/p>\n

IP67, IP68 and Explosion-Proof Rotary Actuators<\/h2>\n

Industrial rotary actuators are often installed outdoors, in humid treatment plants, near process equipment or in other demanding environments. The actuator housing must therefore provide protection appropriate to the installation.<\/p>\n

IP67 Rotary Actuator<\/h3>\n

An IP67 rotary actuator provides strong dust protection and protection against temporary water immersion under the conditions defined by the applicable ingress-protection standard. It is commonly used for many outdoor and industrial installations.<\/p>\n

IP68 Rotary Actuator<\/h3>\n

IP68 electric rotary actuators are used where more demanding protection against water ingress is required. Because IP68 conditions can vary by product, the actual immersion depth, duration and manufacturer’s test conditions should be confirmed before selection.<\/p>\n

Explosion-Proof Rotary Actuator<\/h3>\n

Oil and gas, chemical processing and other hazardous locations may require certified explosion-protected electric actuators. The required certification should match the hazardous-area classification specified by the project.<\/p>\n

IP rating and explosion protection are not the same. IP protection addresses ingress of dust and water, while explosion-protection certification addresses ignition risks in hazardous atmospheres.<\/p>\n<\/div>\n<\/section>\n

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Duty Cycle<\/span><\/p>\n

Why Rotary Actuator Duty Cycle Matters<\/h2>\n

An electric motor generates heat whenever the actuator operates. If the actuator cycles more frequently than its design permits, internal temperature can increase and thermal protection may activate.<\/p>\n

A pipeline isolation valve that operates only a few times each day has very different requirements from a modulating valve that continuously adjusts position during production.<\/p>\n

Rotary actuator duty cycle should therefore be selected according to operating frequency, actuator load and ambient temperature. There is no universal duty-cycle percentage that is suitable for every actuator or application.<\/p>\n<\/div>\n<\/section>\n

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\u0420\u0430\u0431\u043e\u0447\u0430\u044f \u0441\u043a\u043e\u0440\u043e\u0441\u0442\u044c<\/span><\/p>\n

How Fast Should a Rotary Actuator Operate?<\/h2>\n

Actuation time is another important selection parameter. Faster valve movement is not automatically better.<\/p>\n

Fast operation may be required in some emergency isolation systems or process sequences. In water pipelines, however, closing a large valve too quickly can increase the risk of hydraulic surge or water hammer.<\/p>\n

The correct opening and closing time should therefore be selected according to process requirements, pipeline hydraulics, valve size and equipment protection rather than simply choosing the fastest available actuator.<\/p>\n<\/div>\n<\/section>\n

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Fleyenda Rotary Actuators<\/span><\/p>\n

Rotary Electric Actuator Options from Fleyenda<\/h2>\n

Fleyenda provides quarter-turn electric rotary actuator solutions for ball valves, butterfly valves, dampers and industrial automation systems, with multiple torque, control and environmental-protection configurations.<\/p>\n

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Quarter-Turn Electric Actuator<\/span><\/p>\n

FLE Series Electric Rotary Actuator<\/h3>\n

The FLE Series is designed for 0\u201390\u00b0 quarter-turn valve automation and can be paired with ball valves, butterfly valves and other compatible rotary equipment. Different torque, voltage and control configurations are available for industrial applications.<\/p>\n