HUS Series Quarter Turn Electric Valve Actuator for Valves

• Applications: Basic open/close valve isolation.
• Signal Input: Power supply line (220VAC / 380VAC / 24VDC) drives motor directly.
• Signal Output: Passive dry contact signals for fully open and fully closed limit positions.
• System Interface: Connects directly to basic relay boxes, switches, or PLC digital output cards.

• Applications: Proportional flow regulation and throttling control.
• Signal Input: Analog control signal (4–20mA, 0–5V, or 2–10V).
• Signal Output: Analog position feedback signal (4–20mA).
• System Interface: Connects to PLC analog I/O channels for continuous closed-loop position control.

• Applications: DCS integration and explosion-proof hazardous zones.
• Signal Input: Analog signal (4–20mA) or optional HART 7.0 digital fieldbus.
• Signal Output: Continuous 4–20mA feedback, digital diagnostic status, and active fault alarms.
• System Interface: Integrates with DCS control rooms and handheld calibrators via HART or non-intrusive infrared setup.

Feature & Technical Spec

Engineering & Buyer Advantage

Certifications & Compliance

Hearken Flow HUS Series quarter-turn electric valve actuators are CE-, SIL 3-, and ISO 9001-certified. ATEX & IECEx approved (Exd IIC T6Gb / Ex tb IIIC T80°C) with standard IP67 or optional IP68 submersible ratings.

International explosion-proof certificates simplify project audits for you and avoid customs delays during import.

Direct ISO 5211 Flange & Spline Drive

Direct mounting from HUS0S through HUS5+G onto standard ISO 5211 top flanges (F03 to F16). Output shaft can connect double-square, keyway, or flat stems via Hearken Flow’s spline shaft drive.

Direct top-flange mounting cuts assembly time and saves installation space. The output shaft drives ball, butterfly, and plug valves smoothly.

Clutchless Manual Override System

We use an internal worm gear drive. Includes push-type handwheels, clutchless handwheels, or square spanner drives depending on actuator size

During power outages, we can turn the HUS series quarter-turn electric valve actuator’s handwheel directly without a clutch lever.

Industrial Motor & Dynamic Braking

Fully enclosed Class F induction motor with low rotational inertia and internal thermal overload protection. Includes 3-phase dynamic motor braking.

Dynamic motor braking stops coasting for accurate valve positioning. Internal thermal sensors protect the motor during heavy use.

Automatic Phase Correction & Circuit Safety

Automatic 3-phase sequence correction (380V/440V). Adjustable motor stall protection (1–25.4s) and instantaneous reverse-rotation time delay.

Our HUS electric actuator’s automatic phase detection corrects wiring mistakes at startup to protect internal gears if a valve jams or receives a sudden reverse signal.

Dual Overtorque Protection Suite

Combines mechanical limit switches with electronic overtorque power cut-off.

Hearken Flow HUS Series quarter-turn electric actuator will automatically cut off motor power at high torque to protect valve stems and internal gears from damage.

Non-Intrusive Calibration & 3-Zone LCD

128×64 backlit LCD screen with 3D pointer. Set parameters via infrared remote control or 4 buttons on the RPC board.

Our HUS series electric actuator can configure limits with the infrared remote control without opening the cover to keep weather and explosion-proof seals intact.

High-Accuracy Modulating & Fail-Safe Action

Hearken Flow HUS series electric actuator’s RPC control card with single-turn absolute encoder < ±0.2 % error. Configurable signal-loss safety action.

High-precision modulation ( < ±0.2 % error) provides smooth flow control. If signal drops, Hearken Flow HUS series quarter-turn electric valve actuators will move automatically to the preset safe position.

HART 7.0 Digital Fieldbus Integration

Optional HART 7.0 protocol over 4–20mA wires (up to 1,500m distance).

Hearken Flow HUS series quarter-turn electric valve actuator can send real-time data (position %, command %, motor current, and temperature) to DCS control systems or HART handheld calibrators.

Corrosion Protection & Thermal Isolators

Anodized aluminum body with powder coating. Optional space heater (Code X) and extension brackets

We apply heavy-duty powder coating to protect the aluminum body from rain and chemicals. Internal heaters stop moisture, while extension brackets block steam pipe heat.

100% Bench Testing & Batch Traceability

Testing for internal/external seal leakage, rotation angle, and output torque. Stamped with production date, size, and serial number.

Every Hearken Flow HUS series quarter-turn electric valve actuator is tested for torque, angle, and zero leakage before shipping. Serial-number tracking and an 18-month warranty back every order.

Performance features

Description

Shell

The shell is made of aluminum alloy, anodized, and coated with polyester powder.

Protection Grade

IP 67, Exd IIC T6Gb(TBD), Ex tb IIIC T80°Cdb(TBD)

Motor

Totally enclosed cage induction motor, Low rotational inertia, insulation class F, built-in overheat protection.

Hand wheel & endless screw

After a power failure, the hand wheel can be used for manual control. The internal endless screw design, no clutch, light, and easy to control

Mounting base

ISO 5211 Design, high versatility; the transmission shaft adopts a spline shaft design.

Limit Configuration

Mechanical Limiter + Electrical Limiter

Limiter

Power cut-off + passive feedback (Vmax 250V, Imax 5A)

Pointer dial

For valve position indication, it will rotate with the valve

Heater

Used to balance temperature difference and prevent condensation. Ensure that the internal electrical components work normally (Optional)

Temperature resistance

ON/OFF Types: -20°C~+70°C (-4°F~158°F)

Modulating Types: -20°C~+55°C (-4°F~131°F)

Humidity resistance

Maximum relative humidity 90% (non-condensing)

Seismic capacity

XYZ10g, 0.2~34Hz, 30mins

Problem 

Possible Cause

How do we solve it?

ICM LCD screen shows "Phase Loss" or "Stall Alarm"

Missing phase in 380V/440V line, or media debris jamming the valve disc.

We built automatic 3-phase sequence correction into HUS actuators, though all three phases must be present for operation. When media jams the valve, our motor stall timer trips to protect internal windings. We suggested clearing pipeline debris first—our thermal protection will reset automatically after cooling.

Infrared remote control does not change settings on ICM screen

Dust/oil build-up on LCD, low remote battery, or active menu lock.

In heavy industrial environments, dust or oil can easily build up on the LCD display. It will block signals from the infrared remote. We suggest wiping the LCD clean and checking remote batteries. Hearken Flow also built a dedicated key sequence on the remote to unlock the setup menu.

4–20mA position feedback error on RPC modulating card

Zero and full travel position offset after valve mounting, or reversed polarity.

When actuators are mounted onto the valve, minor mechanical alignment shifts can occur. We designed our RPC board with a 4-button "One-Key Auto-Calibration" routine to reset 0% and 100% travel points in seconds without extra tools.

HART 7.0 fieldbus not communicating (HART models)

Loop resistance outside 250 Ω–1100 Ω range or electrical noise on signal lines.

Our HART module requires loop resistance between 250 Ω and 1100 Ω for digital communication with calibrators. We advise using shielded twisted-pair cables with single-point grounding to avoid electrical noise interference.

Actuator moves to unexpected position when 4–20mA signal drops

Fail-safe option configured to Open or Close instead of Stay.

Hearken Flow provides three factory-preset fail-safe actions during control signal loss: Stay in place, Fully Open, or Fully Close. We can pre-set this logic at our factory, or you can update it via the RPC menu and infrared remote.

Handwheel turns, but valve stem does not rotate

Shaft coupling disengaged, or valve stem key sheared under pipe pressure.

HUS series quarter-turn electric valve actuators use an ISO 5211 shaft mounting. If the handwheel turns freely without moving the valve, we advise unbolting the top flange to inspect shaft alignment and verify stem key integrity.

Water or moisture found inside terminal box

Cable glands unsealed or space heater left unpowered in outdoor.

To avoid moisture ingress in outdoor installations, we advise sealing all cable entry glands. Where our Code X PTC space heater is installed, we advise keeping it continuously powered to avoid internal condensation.