HQ Series High Torque Industrial Electric Quarter-Turn Actuators (50 – 5,000 N·m)

Feature & Technical Spec

Engineering & Buyer Advantage

Torque Range: 50 – 5,000 N·m

HQ Series electric quarter turn actuator models range from the HQ005 (50 N·m) to the HQ500 (5,000 N·m), with consistent operating speeds (15 to 60 seconds for a 90° stroke).

You can use the same actuator series to automate the entire range of valves—from DN32 ball valves to DN700 butterfly valves and DN1600 aeration valves—thereby significantly reducing procurement and inventory costs.

Standard ISO 5211 Mounting & Interchangeable Drive Sleeves

Standardized mounting flange interfaces are available in sizes F05 through F25, equipped with modular drive inserts (including double-sided holes, octagonal holes, or keyway types).

The HQ Series electric quarter-turn actuators can be mounted directly onto standard valve top flanges without the need for expensive custom brackets or external couplings, thereby reducing OEM assembly time by up to 60%.

Clutchless Manual Override Handwheel

Our actuators are equipped with an integrated handwheel mechanism featuring a high reduction ratio (60:1 to 348:1), enabling automatic switching between electric and manual modes without the need for a manual clutch lever or handle.

During a power outage, you can easily open or close large valves manually. When power is restored, the HQ Series electric quarter-turn actuators automatically resume electric operation without the risk of mechanical damage or personal injury.

Rugged and Durable ADC12 Die-Cast Aluminum Enclosure

Hearken Flow HQ actuators are manufactured from precision die-cast ADC12 aluminum alloy, with the housing surface treated with a high-temperature-cured, electrostatic anti-corrosion powder coating.

Our HQ actuator's enclosure is both ultra-lightweight and sturdy, which not only greatly reduces international air or sea freight costs and facilitates installation by one person, but also avoids excessive bending stress on small valve pipelines.

Hardened 40Cr Alloy Steel Worm Gear Drive Mechanism

Internal transmission uses heat-treated, precision-machined 40Cr alloy steel worm shafts and worm gears with inherent self-locking function.

When subjected to pressure fluctuations, vibrations, and dynamic fluid impacts in pipelines, the valve maintains its position securely without reverse drive or position drift, ensuring exceptional wear resistance and long-term mechanical reliability under high-intensity cyclic operating conditions.

Dual-travel Limit Switches and ±5° Mechanical Limit Stops

The HQ Series electric actuators are equipped with four standard built-in micro switches (LSO1/LSO2 for open limit and feedback, LSC1/LSC2 for closed limit and feedback), as well as externally adjustable mechanical limit bolts with locking nuts.

Our actuator can perform precise calibration of the valve’s 0° and 90° positions, thereby avoiding seat leakage and preventing actuator stroke overshoot.

Built-in Torque Overload Protection Mechanism (TSO / TSC)

The integrated mechanical torque switch continuously monitors the real-time drive torque during valve opening and closing.

If the valve becomes jammed due to debris in the pipeline or scale buildup, the system automatically cuts off power to the motor, thereby protecting the valve stem, valve disc, and internal gearbox from permanent structural damage.

Class F Heavy-Duty Motor with Thermal Protection

Our actuators use high-starting-torque motors with Class F insulation and an S2 duty cycle (i.e., capable of continuous operation for 10–15 minutes at rated load), and feature a built-in thermal protection device (TH switch).

Ensures reliable operation under high-frequency regulation conditions and prevents failures or degradation of motor winding insulation caused by overheating.

Multi-Voltage Power Supply

Standard power supply: Three-phase AC 380 V (50/60 Hz) or single-phase AC 220 V (50/60 Hz). Additional voltage options are available: AC 24 V, AC 110 V, AC 440 V, AC 660 V, and DC 12 V / DC 24 V / DC 220 V.

Whether in municipal water supply systems, marine applications, off-grid solar systems (DC 24V), or heavy-duty industrial facilities—across a wide range of global applications—power can be supplied directly without the need for an external step-down transformer.

Control Modules: Switching Type, 4–20 mA Control Type, and Non-Intrusive Smart Type

HQ Series electric quarter-turn actuator supports standard switch control (with passive dry-contact feedback), smart proportional control (4–20 mA / 0–10 V input and output), and smart integrated control with local/remote push-button operation.

It can be easily adapted to basic on/off fluid piping systems and also meets the requirements of high-precision automated chemical or HVAC process control loops (with a control sensitivity of up to 0.1%).

Smart Modbus RTU (RS485) Bus Control & 16-Bit Diagnostics

Uses the standard two-wire half-duplex Modbus RTU protocol and features 2 kV optocoupler signal isolation. The 16-bit status register provides detailed fault codes (E1 through E16: covering faults such as motor stalling, phase loss, overtemperature, overtorsion, and signal interruption).

You can remotely read real-time valve positions and diagnose faults from the control room without having to remove the actuator enclosure.

IP67/IP68 Weatherproof and Exd IIB T4 Explosion-Proof Enclosure

We use an O-ring seal design with a protection rating of IP65/IP67 (optional IP68 submersion rating); certified for use in explosive gas environments of Class IIA/IIB, Groups T1–T4; Operating temperature range: -20°C to +60°C (optional: -40°C to +70°C).

Certified for use in harsh environments and hazardous areas; helps EPC contractors and distributors comply with regulations when bidding on projects such as water treatment plants, outdoor refineries, and hazardous chemical pipeline projects.

Direct Factory Supply, OEM Customization & 18-Month Warranty

Enjoy direct-from-manufacturer pricing, backed by ISO 9001, CE, ATEX, RoHS, and SIL 3 quality system certifications. All HQ series electric quarter-turn actuators are passed 100% torque and pressure testing before shipment and come with an 18-month warranty.

You’ll receive wholesale discounts through direct factory supply, private-label customization services (such as laser-engraved logos and custom colors), and reliable replacement support, allowing you to maximize your channel profit margins.

Problem

Possible Cause

How do we solve it?

Motor does not run or respond to open/close commands

The power line is disconnected, there is a fault in the external control circuit, or the internal thermal protection switch (TH) has tripped.

We need to check the main power cable connections and the supply voltage. Check the wiring of the external control circuit connected to terminals 4, 5, and 6. If the motor has overheated due to continuous cyclic operation, wait for it to cool down so that the built-in thermal protection switch can reset automatically.

The output shaft rotates in the opposite direction of the command signal.

The phase sequence of the three-phase AC 380 V power supply wiring is reversed.

We need to press the “Stop” button immediately to avoid the valve from seizing. Disconnect the three-phase power supply, swap any two of the three phases (U, V, W) at the terminal block, and then retest the rotation direction.

The motor stops during operation (torque trip / Modbus error codes E11, E12)

The valve disc or ball is jammed by debris in the pipeline or severe scale buildup, or the internal torque control switch (TSO/TSC) has been triggered.

Manually turn the clutchless handwheel to check whether the valve rotates smoothly. Remove any debris from the pipeline obstructing the valve. If the valve’s torque requirements match the HQ actuator’s rated parameters, check and calibrate the torque switch settings (TSO for the open direction, TSC for the closed direction).

Motor overheating or frequent thermal overload trips (Modbus error codes E8, E10)

Continuous operating time exceeds the rated value for the S2 10-minute duty cycle, a phase is missing from the three-phase power supply, or the HQ actuator was selected with insufficient torque.

We need to stop operation immediately and allow the motor to cool. Check the three-phase line voltage and resolve the phase loss issue. Verify the valve’s actual operating torque against the HQ selection table to ensure there is a sufficient safety margin.

Actuator does not stop at end position (Over-travel) or feedback lamp fails

The limit cam of the microswitch is loose or improperly adjusted, or the mechanical limit bolt is set incorrectly.

Manually operate the valve to the fully closed position, loosen the output shaft cam screw, and turn the closing cam clockwise until it engages microswitch LSC1/LSC2 and emits a “click” sound; then tighten the screw. Repeat the above steps for the open position (LSO1/LSO2). Adjust the external mechanical limit bolts to ensure there is a 1–2-turn buffer after the microswitch actuates.

Open & Close Command Conflict (Modbus E7) at the same time

A wiring fault in the external PLC or relay output has caused the remote “On” and “Off” control signals to be activated at the same time.

We need to check the logic of the external control system and the wiring at terminals 4, 5, and 6. Ensure the remote interlock relay or PLC program prevents the simultaneous issuance of “On” and “Off” commands.

4–20mA control signal is lost or hunting (Modbus E6)

The analog control loop cable is disconnected, the wiring polarity is reversed, or there is severe line interference.

Use a multimeter to check the continuity and polarity of the 4–20 mA input/output wiring loop. Ensure that shielded twisted-pair cable is used and that it is properly grounded at a single point to avoid electromagnetic noise.

Position Acquisition Error or Zero/Range Calibration Failure (Modbus E2, E3)

The calibrated angle difference between the fully closed and fully open positions is too small, or the feedback potentiometer has been rotated beyond its valid electrical travel range.

Recalibrate the 0% (fully closed) and 100% (fully open) travel limits. Fine-tune the position of the feedback potentiometer to keep the entire angular travel within the valid resistance range.

Limit Switch & Torque Switch Logic Mismatch Alarm (Modbus E14)

The wiring of the limit switch’s microswitch conflicts with the torque switch’s logic (for example, the torque switch contact for the “close” direction is triggered during “open” operation).

Check the microswitch’s terminals and swap the limit switch’s wiring, or adjust the internal software masking parameters via the Modbus command register.