Description

Explosion-proof Multi-turn Actuator BD/BDM-45 Overview

The explosion-proof multi-turn actuator stands as the cornerstone of modern process control, and the BD/BDM45-C8 series from Bonray redefines what operators expect from a field device. We engineered this intelligent actuator to provide precise, reliable, and continuous management of quarter-turn and multi-turn valves across demanding industries. Whether you operate in power generation, petrochemical processing, marine engineering, or municipal water treatment, this actuator delivers the robust performance you need. At our advanced Bonray manufacturing facility, we built each unit with a focus on non-intrusive design, ensuring installation and maintenance remain simple and safe without compromising the high IP68 environmental protection. Our engineers understand that a multi-turn electric actuator must withstand harsh conditions, so we constructed the box from lightweight, corrosion-resistant aluminum alloy and incorporated a dual-seal structure. This design effectively blocks dust, moisture, and other contaminants from the internal components, guaranteeing long-term operational stability.

What makes the Explosion-proof Multi-turn Actuator BD/BDM-C8 series different from standard electric actuators?

The BD/BDM45-C8 series explosion-proof multi-turn actuator distinguishes itself through its non-invasive design, allowing full configuration via an infrared setting tool or local knobs without removing the electrical cover. This feature, engineered at Bonray’s production lines, prevents environmental ingress and enhances reliability. Furthermore, we integrated a patented BM18 multi-turn absolute encoder position sensor that maintains valve position without battery backup, ensuring you never lose position data, even after a power outage.

Features

We designed the explosion-proof multi-turn actuator BD/BDM45-C8 with a clear focus on user experience and long-term reliability. The high-resolution dot matrix LCD displays valve position as a large digital readout, with a 1% resolution, and shows menus in clear Chinese or English. Red and green LEDs provide instant visual confirmation of valve limits—red for closed and green for open. The non-intrusive design uses magnetic sensors for the control knobs, eliminating the need for through-shafts and potential leak paths. This multi-turn electric actuator features a lubrication system filled with premium grease, making it maintenance-free for its entire service life.

The mechanical transmission uses a high-performance lubrication system. You will never need to add grease. This feature, a hallmark of Bonray’s commitment to durability, reduces wear and tear and extends the product’s operational lifespan. The dual-seal design also protects the electrical compartment even when you open the cover for wiring, keeping sensitive electronics safe from the environment.

Protect Function of Explosion-proof Multi-turn Actuator

We equipped this multi-turn electric actuator with a comprehensive suite of protective features to prevent damage to both the actuator and your valuable valves. The valve position limit protection automatically stops the actuator at the fully open and fully closed positions. Torque overload protection prevents the actuator from operating beyond safe force limits. We also integrated motor overcurrent protection, which halts operation if the motor draws excessive current, preventing burnout.

The actuator features automatic phase correction, which detects and adjusts for incorrect power supply wiring, eliminating installation errors. Instantaneous reversal protection adds a time delay when you change direction, reducing wear on the valve stem and gear train. The built-in phase loss protection prevents the motor from starting if a phase is missing, avoiding overheating. For challenging processes, valve seizure protection temporarily overrides torque protection for a few seconds to help free a stuck valve, a thoughtful design detail from Bonray engineers. Motor thermal protection uses a relay embedded in the windings to monitor temperature directly, stopping the motor before it overheats.

Control Method

We designed the BD/BDM45-C8 explosion-proof multi-turn actuator to adapt to any control strategy. For local control, you can operate the valve directly using the on-unit knobs or the infrared setting tool, choosing between “jog” or “maintained” modes. For remote operation, the actuator accepts various control inputs. Remote switch control lets you use dry contacts or voltage signals for open, close, and stop commands. The actuator also features remote analog control, accepting a 4-20mA signal for precise, modulating positioning.

In critical safety scenarios, the ESD function overrides all other commands. You can configure ESD for high or low-level activation to force the valve to a predetermined safe position—either open, close, or stay put. For digital plants, the multi-turn electric actuator supports fieldbus control with a wide array of optional communication cards. We also offer unique control methods, such as two-wire control (for fail-safe operation like “signal open, no-signal close”) and intermittent duty control. This latter feature allows the valve to move in a pulsing manner to prevent hydraulic shock or fluid surging, showcasing the depth of engineering at Suzhou Bonray.

Model and Type

We classify the BD/BDM45-C8 series into three distinct types to perfectly match your application’s operational intensity. The BD-C8 On-Off Type is a multi-turn electric actuator for applications requiring a standard duty cycle, suitable for up to 60 starts per hour with a duty cycle not exceeding 33.3%. This model is ideal for simple open/close applications. For more demanding processes requiring proportional control, the BD-C8 Intermittent Modulating Type provides the same durability but includes full analog control capabilities. It also handles up to 60 starts per hour and a 33.3% duty cycle.

The BDM-C8 Frequent Modulating Type is a heavy-duty multi-turn electric actuator designed for the most rigorous closed-loop control applications. We engineered it with solid-state relays (no mechanical contacts) and a high-speed, high-precision control chip. This allows it to achieve up to 1200 starts per hour (600 for single-phase) and a duty cycle of 50%. This model delivers exceptional positioning accuracy, making it the superior choice for continuous modulation in industries like chemical processing and flow control. Suzhou Bonray’s modular design lets you choose the exact model and specifications you need.

Specifications

• Power Supply: 380VAC ±10%, 50Hz ±2% (3-phase), or 220VAC ±10%, 50Hz ±2% (1-phase). Other voltages/frequencies (110V, 115V, 208V, 230V, 400V, 415V, 440V at 50/60Hz) are available.
• Control Input: 4-20mA analog, dry contacts, 24VDC, 220VAC pulse/level signals, and fieldbus protocols.
• Feedback Output: 4-20mA analog, 4 configurable bi-stable output contacts, 1 remote indication contact, 1 fault alarm contact.
• Output Torque: 50 N.m to 3500 N.m (up to 300,000 N.m with gearboxes).
• Output Speed: 12 rpm to 144 rpm (varies by model and phase, see Tables 4-1 to 4-4).
• Ambient Temperature: -30°C to +70°C.
• Protection Class: IP68 (waterproof), optional Ex db IIC T4 Gb (gas explosion-proof), Ex tb IIIC T130℃ Db (dust explosion-proof).
• Mounting: Complies with ISO 5210:2017 (GB/T12222-2023) and JB2920-81.

Related product

BD/BDM-C8F Multi-turn Electric Actuator (Remote Version): We designed this variant for extreme environments. The control unit separates from the actuator body via a cable, allowing the electronics to be placed in a cool, safe location while the actuator operates in high-temperature or high-vibration zones. This Bonray solution ensures reliability in the harshest conditions.