AUMA SAREx Explosion-Proof Modulating Multi-Turn Actuator
Overview: Continuous Modulating Control in Hazardous Areas
The AUMA SAREx Explosion-Proof Modulating Multi-Turn Actuator is the modulating-duty counterpart to AUMA’s SAEx range, engineered for valve applications that require frequent, continuous positioning between fully open and fully closed rather than simple open-close operation, all within a certified explosion-proof housing suitable for classified hazardous areas. Where the SAEx is optimized for open-close (Class A) or positioning (Class B) duty, the SAREx is rated for modulating duty – ISO 22153 Class C – at S4-25% intermittent duty, with special versions available for S4-50% where higher duty cycles are required.
As a trusted supplier of AUMA valve actuators, Seven Star LLC sources and supplies the SAREx explosion-proof modulating actuator to refineries, gas processing plants, and petrochemical facilities across Oman and the wider GCC. Because continuous process control valves in hazardous areas depend on both certified safety and modulating durability, Seven Star LLC helps engineering teams specify the correct SAREx configuration for their control loop and classified zone requirements.
Working Principle: Continuous Positioning with Explosion Protection
The SAREx drives a multi-turn valve stem through an integral gear train, with limit and torque sensing providing continuous feedback that allows the actuator to be positioned anywhere between fully open and fully closed rather than only at the two end stops. This modulating capability is what distinguishes Class C duty from simple open-close operation: the actuator must be able to accept frequent positioning commands from a process control loop and settle accurately at intermediate valve positions without excessive wear or thermal stress, hence the S4-25% intermittent duty rating that reflects a defined ratio of running time to rest time appropriate for modulating service.
As with the SAEx range, the SAREx’s explosion-protected construction ensures that motor windings, switch compartments, and terminal areas cannot act as an ignition source, with certification performed in close collaboration with national and international certification bodies. For plants requiring integral local control, the AUMA MATIC AMExC 01.1 actuator controls pairing provides push-to-run or self-retaining control logic, torque or limit seating selection, and automatic phase correction, all within the same explosion-protected envelope.
Engineering Design of the SAREx Actuator
The SAREx is built to IP68 protection standard with single-phase and three-phase motor options depending on model, and covers a torque range from approximately 15 Nm up to 1,600 Nm in modulating service, with output speeds from 4 to 90 rpm, suiting a wide range of modulating valve sizes from small control lines to medium process valves. Ambient temperature rating spans -30°C to +70°C as standard, supporting reliable modulating operation across the temperature extremes common to Gulf-region outdoor plant installations.
The actuator is designed for compatibility with AUMA MATIC AMExC 01.1 controls for multi-turn actuators in the SAEx/SAREx 07.2 to 16.2 size range, giving specifiers a proven, explosion-protected control package rather than needing to integrate separate remote control electronics in the hazardous area.
Key Features
The AUMA SAREx Explosion-Proof Modulating Multi-Turn Actuator delivers certified continuous positioning for hazardous-area process control. Key characteristics include:
- Modulating duty rating (ISO 22153 Class C) at S4-25%, with S4-50% versions available.
- Explosion-proof construction certified for installation in classified hazardous areas.
- IP68 protection class for reliable sealing against dust and water ingress.
- Modulating torque range from 15 Nm to 1,600 Nm; output speeds 4 to 90 rpm.
- Compatible with AUMA MATIC AMExC 01.1 explosion-protected actuator controls for integral local control.
- Ambient temperature range of -30°C to +70°C for outdoor and harsh-climate installations.
Industrial Applications
The SAREx actuator is deployed wherever a multi-turn control valve requires frequent, continuous modulating operation within a classified hazardous area, including refinery process control loops, gas processing plants, and chemical facilities where flow, pressure, or level control valves must respond dynamically to changing process conditions. Its ATEX-class certification makes it the compliant specification choice for these duty profiles rather than a simple open-close SAEx unit.
Seven Star LLC supports refinery engineering teams, EPC contractors, and plant maintenance departments across Oman, Muscat, Sohar, and the broader GCC region with sourcing of AUMA explosion-proof modulating actuators, helping projects meet both process control and hazardous-area compliance requirements.
Technical Specifications
The table below summarizes the core specifications of the AUMA SAREx Explosion-Proof Modulating Multi-Turn Actuator as supplied by Seven Star LLC.
| Parameter | Specification |
|---|---|
| Model | AUMA SAREx Series |
| Type | Electric, explosion-proof, multi-turn actuator |
| Duty Rating | Modulating duty, Class C, S4-25% (S4-50% available) |
| Motor | Single-phase or three-phase depending on model |
| Protection Class | IP68 |
| Torque Range | 15 Nm to 1,600 Nm (modulating); 15 Nm to 4,000 Nm overall platform range |
| Output Speed | 4 to 90 rpm |
| Ambient Temperature | -30°C to +70°C |
| Explosion Protection | ATEX II 2G Ex db eb IIC (IIB) T4 (T3) Gb; IECEx Ex db eb IIC (IIB) T4 (T3) Gb; FM Class I Div 1 Groups (B), C, D T4 (T3C) |
| Starts per Hour (max.) | 1,200 c/h |
| Compatible Controls | AUMA MATIC AMExC 01.1 |
Duty Class, Torque Rating and Starting Frequency
Two AUMA figures matter when sizing a AUMA SAREx unit, and they are not the same number. AUMA publishes an overall torque range of 15 Nm to 4,000 Nm for the SAREx platform, but a separate and lower modulating torque range of 15 Nm to 1,600 Nm. The modulating figure is the one that governs Class C service: an actuator run in a continuous control loop dissipates far more heat in the motor and gearing than the same frame size performing a handful of open-close strokes per shift, so AUMA derates the usable torque accordingly. Specifying against the 4,000 Nm headline figure for a modulating loop is the most common sizing error on this range.
The companion figure is starting frequency. AUMA rates the SAREx for a maximum of 1,200 starts per hour, which is what allows a control loop to hunt around setpoint without exceeding the actuator’s thermal envelope, and output speeds are published as 4 to 90 rpm – deliberately narrower at the top end than the 4 to 180 rpm offered on the open-close SAEx range, because high output speeds are of little use in modulating service and would only worsen positioning overshoot.
Hazardous-Area Certification Detail
The SAREx carries a full set of international hazardous-area approvals rather than a single regional certificate, which matters for Oman and GCC projects where an EPC specification may reference ATEX, IECEx and FM in the same document. AUMA publishes the ATEX marking as II 2G Ex db eb IIC (IIB) T4 (T3) Gb, the equivalent IECEx marking as Ex db eb IIC (IIB) T4 (T3) Gb, and an FM listing as Class I Division 1 Groups (B), C, D T4 (T3C). The db eb protection concept combines a flameproof enclosure for the motor and switching compartment with increased-safety terminal compartments, and the IIC gas group covers hydrogen-bearing streams found in refinery hydrotreater and hydrogen plant service. Functional safety up to SIL 3 is achievable when the SAREx is combined with compatible AUMA controls.
Request a Quote for AUMA SAREx Explosion-Proof Modulating Multi-Turn Actuator
Seven Star LLC supplies the AUMA SAREx explosion-proof modulating multi-turn actuator with full manufacturer documentation and regional technical support. Contact our instrumentation and valve automation division for a formal RFQ, to confirm the correct actuator size and duty class for your process control application, or to obtain the complete technical datasheet. Seven Star LLC ensures every unit shipped across Oman and the GCC is genuine, correctly configured, and backed by local engineering support.
Related Products
- Datasheet AUMA SAREx 07.2 - SAREx 16.2 Datasheet Download
AUMA actuator and gearbox types
SA multi-turn actuators handle open-close duty on gate and globe valves, and SAR is the modulating version; the listing includes the SA 07.2, SA 10.2 and SA 25.1. SAEx and SAREx are the explosion-proof equivalents. Part-turn duty on ball and butterfly valves is covered by SQ and the modulating SQR, or by an SA actuator combined with a GS part-turn gearbox. LE linear thrust units convert multi-turn output to thrust, and GHT multi-turn gearboxes extend the torque range up to 120,000 Nm. PROFOX is the compact actuator line. Special items include the seawater-resistant SGM and SGMR part-turn actuators with bronze housings, the SVC and SVCR globe valve actuators and the FQM fail-safe unit. Integral controls come as AM or AC versions.Where AUMA electric actuators are used
AUMA actuators are found in water, power, oil and gas, marine and general industry. In practice that means isolation and control valves in water treatment and pumping stations, power plant steam and cooling systems, tank farms and pipelines, and sluice gates and dampers.Ordering AUMA actuators and parts: what we need
For a replacement send photos of the actuator, motor and controls nameplates: type, order number, serial number and wiring diagram number. For a new actuator we need:- valve type, required torque or thrust, and turns or stroke
- valve mounting flange and stem or shaft details
- output speed, duty (open-close or modulating)
- supply voltage and frequency, control signals or fieldbus
- enclosure protection, ambient temperature, Ex requirement
Browse AUMA products by category: Valve Actuator, Industrial Communications.
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