AUMA SQR 05.2 Modulating Part-Turn Actuator

Overview

AUMA SQR 05.2 is the smallest member of the modulating SQR .2 range, designed for valves that sit inside a control loop and are repositioned many times an hour. Its tripping torque can be adjusted between 75 Nm and 150 Nm, but the figure that matters for control duty is the maximum modulating torque of 75 Nm at S4 – 25 %. That distinction between tripping and modulating torque is the first thing to understand when choosing between an SQ 05.2 and an SQR 05.2.

In Oman and the GCC, Seven Star LLC proudly supplies the AUMA SQR 05.2 to process, HVAC and utility customers in Oman and the GCC. We help engineers in Muscat, Sohar and Salalah check the control valve torque, the flange pattern and the positioner interface so the loop performs as designed from the first day.

Modulating Duty at the Small End

A modulating actuator receives a setpoint, moves a short distance, stops and holds, and then repeats the cycle as the process drifts. The AUMA SQR 05.2 is built for this pattern with a rating of up to 1,500 starts per hour, a pulse duration of 50 ms for movement in the same direction, and a minimum pulse on reversal of 160 ms at the fastest 8 s ratio rising to 800 ms at the slowest 63 s ratio. These figures define how finely the actuator can step and how quickly it can reverse direction without overshooting.

Six operating times are offered at 50 Hz: 8, 11, 16, 22, 32 and 63 seconds. The fast ratios give a responsive loop for flow control on compact lines, while the 63 s ratio gives a very gentle stroke for sensitive systems. The S4 – 25 % rating covers a modulating torque of up to 75 Nm, and an S4 – 50 % option, available for all but the 63 s ratio, allows 55 Nm modulating torque, with the maximum tripping torque limited to 110 Nm. Choosing the duty class early avoids thermal overload in service.

Engineering Design of the AUMA SQR 05.2

The housing and mechanical interface of the AUMA SQR 05.2 are those of the SQ .2 family: an F05/F07 flange with F10 option, a splined coupling for shafts up to 25.4 mm cylindrical, 22 mm square or 22 mm two-flat, and a 160 mm handwheel that needs 11 or 16 turns for 90 degrees. This means installation drawings prepared for the open-close SQ 05.2 carry across, which simplifies conversion of an on-off valve to a control valve.

The unit weighs about 21 kg, or 27 kg with base and lever, and roughly 23 kg and 29 kg in the 1-phase AC version. Protection is IP68 with KS corrosion protection as standard. For positioning, the actuator is combined with AM or AC actuator controls, which accept an analogue setpoint or fieldbus telegram and return position and status, and with the electronic magnetic limit and torque transmitter available through the AC controls.

Key Features

The AUMA SQR 05.2 brings control-valve capability to a compact, light housing.

• Rated for modulating duty S4 – 25 % with up to 1,500 starts per hour for closed-loop control.
• A 75 Nm to 150 Nm tripping torque range with a 75 Nm modulating torque suits small control valves.
• A 50 ms pulse duration and reversal pulses from 160 ms support fine positioning steps.
• Six operating times from 8 s to 63 s let the loop speed be matched to the process.
• An S4 – 50 % option raises the duty rating at reduced modulating torque for demanding loops.
• F05/F07 flange with F10 option and shafts up to 25.4 mm cover typical compact valves.
• IP68 and KS protection give reliable service outdoors and in humid plant rooms.
• AM and AC controls add analogue setpoint, fieldbus communication and diagnostics.

Selection Guidance for the AUMA SQR 05.2

Before ordering the AUMA SQR 05.2, separate the two jobs the actuator performs. Seating the valve needs the tripping torque, anywhere from 75 Nm to 150 Nm, while positioning it in service needs only the modulating torque of up to 75 Nm. A valve whose in-service torque is close to 75 Nm is at the limit of this frame and should be moved up to the SQR 07.2, because a modulating drive that regularly works at its rating runs hotter and wears faster.

Next, choose the stroke time from the process, not from habit. A fast 8 s ratio makes a nimble loop but can excite oscillation if the controller is aggressive, whereas 22 s or 32 s is often smoother for flow control. Finally, check the supply: the 1-phase AC version weighs about 2 kg more than the 3-phase unit, and AM or AC controls must be chosen to match.

Industrial Applications

The AUMA SQR 05.2 belongs on small control valves where precise positioning matters but torque demand is modest: temperature control on heat exchangers, flow regulation on chemical dosing skids, and air-flow dampers on large building HVAC systems. District cooling operators in Muscat use this size for branch balancing valves, while compact process skids in industrial zones use it where an SQ would wear out quickly from frequent small moves.

In Oman and the GCC, Seven Star LLC supplies the SQR 05.2 with local support. Where the torque demand is higher, look at the next frame.

Larger modulating options include the AUMA SQR 07.2.

The open-close equivalent is part of the AUMA SQ part-turn actuator range, variable-speed drives are described under the AUMA SQV variable-speed part-turn actuator, and controls under the AUMA MATIC AM/AC integral actuator controls.

Technical Specifications

The table summarises AUMA’s published data for the AUMA SQR 05.2 with a 3-phase AC motor in modulating duty.

Request a Quote for AUMA SQR 05.2

Seven Star LLC welcomes RFQs for the AUMA SQR 05.2 from control engineers and procurement teams in Oman and the GCC. Tell us the control valve make, the modulating torque, the supply voltage and the setpoint interface, and we will respond with a formal quotation, stock position and the technical data sheet. In Oman and the GCC, we supply every drive on request, with lead time confirmed at quotation. Request a formal AUMA SQR 05.2 offer today.