Description
Multi-turn Electric Actuator Overview
The BD/BDM15-C8 Series Multi-turn Electric Actuator is a cornerstone of modern process control. This intelligent device advances valve automation with robust mechanics and sophisticated electronics. It offers a non-intrusive, user-friendly solution for power generation, petrochemical, water treatment, and marine engineering. At Bonray, we engineer precise torque from 50 N·m to 3,500 N·m, expandable to 300,000 N·m with gearboxes. This product enables reliable remote control of gate, globe, and other multi-turn valves. Our design prioritizes durability and safety. The lightweight aluminum housing meets IP68 as standard, withstanding immersion for harsh environments. A certified flameproof version is available for explosive atmospheres. Combined with advanced protective features, this adaptability ensures long service life while minimizing downtime and maintenance costs.

How does the absolute encoder maintain valve position during a power failure without a battery?
The multi-turn electric actuator uses a non-contact, multi-turn absolute encoder. Unlike incremental sensors, this system directly and permanently tracks the valve’s position. It requires no battery backup to retain this data. Even after a prolonged power outage, the actuator knows the exact valve position the moment power is restored, eliminating the need for re-initialization and enhancing operational reliability.
Features
The BD/BDM15-C8 Series Multi-turn Electric Actuator incorporates a range of features designed for superior performance and ease of use.
Non-Intrusive, Intuitive Setup: Our engineers prioritized user convenience. You set up and configure the multi-turn electric actuator without ever removing the cover. A magnetic selector knob and an optional infrared setting tool allow you to navigate the high-resolution dot-matrix LCD screen, which displays all menus, valve position, and diagnostic messages in clear, plain text. This design eliminates a common point of failure—shaft seals—and protects internal electronics from moisture and dust ingress, ensuring long-term reliability.

LCD Display Absolute Encoder Technology: We equip the multi-turn electric actuator with an advanced, non-contact absolute encoder for valve position sensing. This sensor retains the exact valve position even during a total power loss, eliminating the need for battery backup and the associated maintenance. You never need to re-initialize the unit after a power failure, saving time and preventing potential operational errors.

Absolute Encoder Integrated Continuous Torque Measurement: The multi-turn electric actuator provides real-time torque monitoring. The system displays the current torque on the LCD and allows you to set a precise torque protection limit (from 30% to 100%). This proactive protection prevents damage to both the valve and the actuator in case of jamming or seat overloading.
Multiple Control Options: The multi-turn electric actuator adapts to your control system architecture. It accepts standard remote switch commands, 4-20 mA analog signals for precise modulating control, and ESD (Emergency Shut Down) overrides. For modern digital plants, we offer plug-in fieldbus cards, including Profibus-DP, Modbus, DeviceNet, and HART, transforming the unit into a fully integrated node on your industrial network.
Comprehensive Protection Suite: We build intelligence into the multi-turn electric actuator to safeguard itself and your valve. This includes automatic phase rotation correction (eliminating wiring worries), instantaneous reversal protection, motor over-temperature protection (using embedded thermal relays), and power loss phase protection. These features work in the background to ensure uninterrupted and safe operation.
Integrated Data Logger: The multi-turn electric actuator features a built-in data logger that records operational statistics, such as the number of cycles, total run time, and the history of alarms and faults. This data proves invaluable for predictive maintenance schedules and rapid troubleshooting, helping you identify potential issues before they cause a failure.
Multi-turn Electric Actuator BD/BDM15-C8 Specifications
- Power Supply: 380 Vac ±10% 50Hz ±2% (3-phase) or 220 Vac ±10% 50Hz ±2% (1-phase). We also offer a variety of other voltages and frequencies (e.g., 400V, 440V, 110V, 60Hz) upon request.
- Control Signals: Accepts dry contacts, 24V DC or 220V AC pulsed/level signals, and 4-20 mA analog input.
- Feedback Signals: Provides 4-20 mA analog output for position feedback. Delivers up to 4 field-configurable, bi-stable output relays (status retains on power loss) and dedicated fault and remote indication relays.
- Output Torque: Ranges from 50 N.m to 3,500 N.m (base unit). Extends to 300,000 N.m with auxiliary gearboxes.
- Output Speed: Multiple speed options available, ranging from 12 to 144 rpm (refer to detailed tables).
- Ambient Temperature: Standard operating range from -30°C to +70°C. We can customize for extreme temperatures.
- Mounting Flange: Conforms to ISO 5210:2017 (GB/T12222-2023) and JB2920-81 standards.
- Ingress Protection: IP68 as standard, ensuring performance after prolonged immersion. Flameproof version available for hazardous locations (Ex db IIC T4 Gb / Ex tb IIIC T130℃ Db).
- Enclosure Material: High-grade aluminum alloy casting.
Related product

BD/BDM-C8F Series (Remote Mount): For applications with extreme temperatures (high heat or cold) or intense vibration, we recommend the BD/BDM-C8F. This variant separates the electronic control module from the actuator mechanism. You install the actuator on the valve in the harsh environment while mounting the control unit in a benign, accessible location. A cable connects the two, allowing for full functionality of the multi-turn electric actuator without exposing the sensitive electronics to damaging conditions.







