Functional contributions of electric actuators in industrial processes

This article discusses the key advantages of electric actuators, focusing on the types, specifics and how they operate.

 Text & images by SMS TORK

Electric actuators are power transmission devices that convert the driving force provided by an electric motor into rotational or linear motion. In rotary electric actuators, the driving force generated by the motor enables the gears within the body to produce rotational movement. This rotation is optimised for specific requirements, such as low speed and high torque for quarter-turn actuators or higher speeds and lower torque for multiturn actuators.

Quarter-turn and multiturn actuators

Quarter-turn electric actuators are commonly used in smaller valves, such as butterfly or ball valves, that require 90-degree rotation for fully open or fully closed positions. In contrast, multiturn actuators are utilised in larger butterfly and ball valves with reducers or directly in globe and knife valves.

Key advantages of electric actuators

The widespread use of electric actuators in industrial applications can be attributed to the following advantages:

• Availability of electricity in most locations
• High torque generation with minimal energy consumption
• Durability and long product lifespan
• Compact and lightweight design
• High protection class
• Precise proportional control capability
• Wide operating voltage range
• Extensive maximum rotation angle tolerance

Electric actuators can be manufactured as on/off controlled electric actuators or proportional controlled electric actuators, depending on the specifications of the connected valve and customer requirements.

• On/off controlled actuators: Provide position feedback at fully open and fully closed positions.
• Proportional controlled actuators: Allow control throughout the entire range of motion and provide real-time position feedback via digital commands or analogue signals (e.g. current or voltage).

Manual operation and user-friendliness

Electric actuators are equipped with a manual operation handle in case of a power outage. The handle’s position, locking system and torque requirements are optimised for user convenience. Excessive torque or an overly large number of turns for opening/closing operations is undesirable. At TORK, these features are designed and produced to be highly ergonomic and user-friendly, based on extensive research, customer feedback and technical calculations.

Precision and reliability

The mechanical gear system in electric actuators ensures consistent speed and torque throughout the motion, enabling precise proportional control. TORK’s quarter-turn actuators provide a precision level of 1% within a 90-degree rotation, while multiturn actuators achieve up to 0.1% precision.

Recognition and awards

Independent organisations have recognised TORK’s actuators. For example, its multiturn electric actuator received respected design awards, including the Good Design Award (USA) and the IF Design Award (Germany), in the industrial design category.

As a testament to TORK’s innovative company culture, it has twice won first place in the “Innovation Cycle” category at the Innovation League Awards organised by the Turkish Exporters Assembly (TIM). This achievement highlights the strong integration of innovation into every aspect of its operations.