AUMA SAREx 07.2 Explosion-Proof Modulating Actuator

Overview

AUMA SAREx 07.2 is the smallest modulating Ex frame. Tripping torque is 15 to 30 Nm (S4-25 %), modulating torque is up to 15 / 8 Nm (S4-25 % / S4-50 %), and the flange is F07 / F10.

Seven Star LLC, a trusted supplier of AUMA products for Oman and the GCC, quotes the SAREx 07.2 as genuine factory equipment for modulating duty in hazardous areas. Projects around Sohar and Muscat receive loop-tuning advice together with the quotation. Related pages: SAREx modulating Ex actuators, SAEx range and AUMA SQEx explosion-proof part-turn actuator.

Operating Principle of the AUMA SAREx 07.2

A 3-phase motor with intermittent-duty rating moves the SAREx 07.2 in short pulses from an AMExC or ACExC positioner. The motor must be powered for at least 50 ms before the output drive moves, and for up to 260 ms at 4 rpm when the direction reverses. AUMA documents the SAREx series as self-locking.

Engineering Design of the AUMA SAREx 07.2

Setting up a modulating loop with the SAREx 07.2 starts with the pulse data: the 50 ms minimum pulse is the shortest correction the motor can deliver, so the controller’s smallest output step should not be below it. At 22 to 23 kg, the actuator is easy to handle, and the 160 mm handwheel allows manual positioning for loop checks before automatic control starts.

Wiring uses the Ex plug/socket connector (KT), spring-clamp control terminals and screw-type motor terminals. The enclosure is IP68, and the motor heater option is 12.5 W.

Key Features of the AUMA SAREx 07.2

What the AUMA SAREx 07.2 offers at a glance:

• Trip torque from 15 to 30 Nm for S4-25 % duty, up to 20 Nm for S4-50 %.
• Continuous positioning torque of 15 / 8 Nm at S4-25 % / S4-50 %.
• Output speeds of 4–90 rpm at 50 Hz, with starts graded by speed band.
• Handwheel diameter 160 mm, approximate weight 22 kg (4–22 rpm), 23 kg (32–90 rpm).
• Motor power of 0.02–0.20 kW at 400 V; pulse timing 50 ms (same direction); on reversal 260 ms at 4 rpm down to 60 ms at 90 rpm.

Selecting the AUMA SAREx 07.2 for Your Valve

The SAREx 07.2 is the smallest modulating Ex actuator in the range. Its torque range is 15 to 30 Nm for S4-25% duty and 15 to 20 Nm for S4-50%, with modulating torque limited to 15 Nm (S4-25%) or 8 Nm (S4-50%). Use it for small control valves or dampers in classified areas where regulation, not seating force, is the main job. The maximum number of starts is 1,200 per hour at speeds up to 45 rpm and 900 per hour from 63 to 90 rpm, and a minimum pulse duration of 50 ms sets the resolution of positioning.

The SAREx 07.2 is the smallest modulating Ex frame: 15 to 30 Nm tripping torque, 15 Nm modulating torque and up to 1,200 starts per hour at 4 to 45 rpm. For loops that need up to 60 Nm tripping torque, the SAREx 07.6 uses the same F07 / F10 flange.

AUMA SAREx 07.2 Modulating Torque and Starts by Speed

The following limits apply to the AUMA SAREx 07.2 at rated voltage and an ambient temperature of +40 °C. Tripping torque is adjustable up to 30 Nm (S4-25 %) or 20 Nm (S4-50 %). Illustrative calculation, not AUMA data: a control valve with 6 turns per stroke needs 90 s at 4 rpm, 16 s at 22 rpm and 4 s at 90 rpm for a full stroke.

Loop-tuning note: for the SAREx 07.2 the data sheet gives a 50 ms minimum pulse and a reversal pulse that shortens from 260 ms at 4 rpm to 60 ms at 90 rpm. Faster speeds resolve corrections more finely in time but reduce the permitted starts from 1,200 to 900 per hour above 45 rpm. A mid-range speed of 22 rpm (90 ms on reversal, 1,200 starts per hour) is a common compromise for small control valves.

Worked Sizing Example for the SAREx 07.2 (Illustrative Calculation)

Consider a small chemical-dosing control valve whose friction torque never exceeds 10 Nm. The SAREx 07.2 offers 15 Nm modulating torque at S4-25 % and 8 Nm at S4-50 %, so the valve is within the S4-25 % limit but above the 8 Nm S4-50 % limit. If the controller commands corrections for more than a quarter of the time, a larger frame such as the SAREx 07.6 (15 Nm at S4-50 %) is the safer choice. This is an illustrative calculation, not AUMA data.

Motor and Electrical Data of the AUMA SAREx 07.2

4 speed points from AUMA’s separate electrical data sheet (S4-25 %, 400 V / 50 Hz), 0.02 to 0.20 kW; approximate values that are not part of the technical datasheet attached here.

Explosion Protection and Installation Notes for the AUMA SAREx 07.2

Standard ATEX markings of the SAREx 07.2 per AUMA: II 2G Ex db eb IIC T4 or T3 Gb, II 2G Ex h IIC T4 or T3 Gb and II 2D Ex tb IIIC T130 °C or T190 °C Db. Certificate: DEKRA 11ATEX0008 X. Confirm temperature class and zone on the nameplate.

Intermittent duty S5-25 % requires insulation class H, while class F (tropicalized) is standard. A resistance heater of 5 W, 24 V AC is installed in the actuator when AMExC or ACExC controls are fitted.

Industrial Applications

The AUMA SAREx 07.2 is used for fine regulation of small flow, pressure or level control valves in hazardous areas, such as fuel-gas conditioning skids, chemical-injection control valves and small vent or purge lines. Its low weight and compact housing allow it to be mounted close to the valve in crowded classified zones.

In Omani oil, gas and petrochemical plants, small modulating valves appear in test separators, flare-header knock-out drum level control and utility systems. Seven Star LLC supplies the SAREx 07.2 together with the Ex-rated controls and documentation required for ATEX plant files.

Technical Specifications

Core data of the AUMA SAREx 07.2 as published by AUMA; the official data sheet remains binding.

Neighbouring sizes and counterparts: AUMA SAREx 07.6 explosion-proof modulating actuator, AUMA SAEx 07.2 explosion-proof actuator and AUMA SAR 07.2 modulating actuator.

Request a Quote for AUMA SAREx 07.2

Share your control-valve data and loop requirements with Seven Star LLC to receive an offer for the AUMA SAREx 07.2. The AUMA datasheet can be opened through the download link on this page.