1. Start with Valve Motion: Which Electric Valve Actuator Type Fits the Valve?

Different valve structures operate in different ways. Matching actuator motion first helps narrow down the correct actuator category and reduces the risk of mechanical mismatch during installation.

SUN YEH provides several actuator platforms for these motion requirements. The OM Series and CM Series support quarter-turn valve automation, while the compact T Series provides lower-torque quarter-turn solutions for installations where space is limited.

For linear movement, the L Series Electric Linear Valve Actuators provide a thrust range from 250 to 2,000 kgf. SUN YEH product literature also includes multi-turn actuator solutions for applications requiring multiple rotations.

2. When Is a Quarter-Turn Electric Actuator the Right Choice?

Quarter-turn valve automation is common in water systems, HVAC, cooling systems, industrial process lines, and airflow control. However, confirming a 90-degree movement only identifies the actuator category—it does not determine the final model.

Engineers and buyers should also confirm:

• Required operating torque
• Breakaway torque
• Valve type and size
• Process pressure
• Media characteristics
• Control mode
• Operating speed
• Installation space
• Environmental protection requirements

SUN YEH’s OM Series covers a torque range from 35 Nm to 4,500 Nm, while the CM Series covers 100 Nm to 600 Nm.

For compact lower-torque installations, the T Series provides 6 Nm and 15 Nm models.

This is why buyers should avoid treating every quarter turn electric actuator as interchangeable. Two actuators may both provide quarter-turn movement but differ significantly in torque range, mounting dimensions, control configuration, operating speed, manual override, and environmental suitability.

3. Size the Actuator by Torque or Thrust—not Valve Size Alone

Two valves with the same nominal size can require different actuator output because operating resistance may vary with pressure, sealing design, valve construction, process media, and valve condition.

For rotary valves, one particularly important value is breakaway torque—the torque required to initiate valve movement from the seated position.

Ignoring breakaway torque can result in an actuator that appears suitable based on nominal valve size but cannot reliably begin valve movement under real operating conditions.

For linear applications, output is evaluated as thrust. SUN YEH’s L Series provides 250 to 2,000 kgf of thrust, with maximum stroke depending on model.

Final actuator sizing should be based on verified valve data and project engineering requirements rather than simply selecting a larger actuator without technical justification.

4. Match Control Method, Power Supply, and Feedback to the Automation System

On/Off Control

On/Off control is suitable when the valve only needs to move between fully open and fully closed positions. Typical examples include isolation and basic flow switching.

Modulating Control

Modulating control is required when the valve must move to intermediate positions for flow, pressure, temperature, or other process regulation.

For example, SUN YEH’s CM Series uses open/close control as standard and offers modulating control as an option, while the L Series is designed with modulating control as a standard feature.

Before ordering, the project team should also confirm:

• Operating voltage
• Control signal
• Required position feedback
• Wiring requirements
• PLC, BMS, DCS, or other system compatibility
• Duty conditions

5. Add Fail-Safe or Explosion-Proof Requirements Only When the Application Demands Them

For hazardous-area projects, site classification, required certification, temperature range, enclosure requirements, and control method should be confirmed before a specific actuator configuration is selected.

6. Check Mounting, Environment, and Maintenance Before Finalizing Selection

Before finalizing the actuator model, confirm the physical connection between the valve and actuator.

• Mounting flange
• Output drive and valve shaft dimensions
• Coupling or adapter requirements
• Available installation space
• Wiring access
• Position indication
• Manual override requirements

SUN YEH’s OM Series , CM Series , and T Series use ISO 5211 mounting interfaces, while the L Series uses ISO 5210 flange interfaces.

The installation environment should also be reviewed for outdoor exposure, humidity, water, dust, corrosion, ambient temperature, vibration, and other site conditions.

Maintenance accessibility matters as well. If operators may need to reposition a valve during commissioning, servicing, or a power interruption, manual operation requirements should be considered during selection.

7. Electric Valve Actuator Selection Matrix: Match the Application to SUN YEH Solutions

For B2B actuator inquiries, providing complete application data can significantly improve the selection process. Useful information includes:

• Valve type and model
• Required torque or thrust
• Operating pressure and media
• Required movement
• Voltage
• Control type
• Feedback requirement
• Fail-safe requirement
• Hazardous-area classification, if applicable
• Installation environment
• Mounting information

8. FAQ: Electric Valve Actuator Selection