ULLI-R Series Integration in Pulp & Paper Automation with Resistive Feedback

The Application

In the pulp and paper industry, consistent and responsive valve automation is essential for controlling steam, water, and chemical flows across various process stages. A valve automation company specializing in integrated control systems was tasked with delivering a complete valve solution for a large-scale paper mill. To meet the client’s requirements for position feedback and system compatibility, the firm selected AOITEC’s ULLI-R series electric actuators.

This project covered key production areas including pulping, bleaching, and water treatment systems. The actuators needed to provide accurate, real-time valve position signals to the plant's central control system (PLC/DCS) for continuous feedback and reliable loop control.

Precision and Compatibility: AOITEC’s ULLI-R Electric Actuator with Resistive Position Feedback

The Solution

AOITEC supplied its ULLI-R series, designed specifically for automation systems requiring high-accuracy position feedback. Equipped with a built-in resistive position sensor, the ULLI-R actuator delivers continuous analog output (0–10V or 4–20mA), ensuring precise valve tracking and seamless integration with centralized control architectures.

Key features of the ULLI-R actuator include:

• Resistive position feedback, providing linear, real-time analog signal output for accurate closed-loop control

• Direct-mount ISO 5211 interface, allowing easy installation on butterfly and ball valves without the need for brackets or couplings

• IP68-rated enclosure, offering full protection in high-humidity, corrosive environments typical of pulp and paper plants

• Overload protection, automatically interrupting actuation in the event of a jam or excessive torque demand

• Compact design with simple wiring, ideal for integration in confined cabinet or pipe-rack installations

  
  

Implementation and Outcome

Throughout the project, AOITEC worked closely with the valve manufacturer’s engineering team to provide onsite support, installation guidance, and signal calibration services. The ULLI-R actuators were successfully integrated into the automated valve assemblies, connecting seamlessly with the paper mill’s control cabinets and SCADA systems.

Post-commissioning results confirmed the following benefits:

• Accurate and stable valve control with reliable position feedback

• Reduced manual intervention and improved system responsiveness

• Lower maintenance frequency due to sealed design and durable construction

• Enhanced automation reliability and long-term operational consistency

To accommodate a wide range of industrial needs beyond the current project scope, AOITEC’s ULLI actuator offers multiple model variations and add-on features：

ulli-xxs:     Four-position switch signal feedback (dry contact or LED)

ulli-xxR:    Potentiometer (resistive) position feedback 

ulli-xxEX:  Explosion-proof design 

ulli-xxw:   Wireless remote control with RS-485 Bus Control 

ulli-xxt:     Electronic bidirectional overload protection 

ulli-xxCB: Super capacitator failsafe function 

ulli-Lxx:     Linear actuator with position indicator light