AUMA SQR Modulating Part-Turn Actuator

Overview

The AUMA SQR is the modulating-duty member of the AUMA SQ .2 part-turn actuator family. Where the standard SQ actuator is built to move a valve between OPEN and CLOSED a few times a day, the SQR is engineered for process control: it is rated for modulating duty, class C, at S4 – 25 %, and tolerates up to 1,500 starts per hour. That capability makes it the natural choice for butterfly valves, ball valves and plug valves that sit inside a control loop and are asked to hold, correct and re-position continuously rather than simply isolate a line. AUMA specifies a torque range of 50 Nm to 2,500 Nm for the SQR .2 type range, of which 75 Nm to 1,200 Nm is the modulating torque range for continuous positioning.

In Oman and the GCC, Seven Star LLC proudly supplies the AUMA SQR to water utilities, process plants, power stations and industrial facilities throughout the Sultanate of Oman, including Muscat, Sohar and Salalah, and across the wider GCC. Our instrumentation division helps engineers match the actuator size to the valve torque curve, select the right integral controls and confirm the swing angle and valve attachment before the order is placed, so the actuator arrives ready to commission on the valve it was specified for.

Operating Principle

Like every AUMA part-turn actuator, the AUMA SQR converts the rotation of a three-phase or single-phase AC motor into a controlled quarter-turn output through a worm-gear stage and a splined output drive shaft. Mechanical end stops define the swing angle, which is adjustable in the range of 75 to 105 degrees, while limit and torque sensing inside the actuator switches the drive off at the set end position or if the set torque is exceeded. The operating time for a 90 degree stroke can be selected between 8 s and 100 s, allowing the closing speed to be matched to the pipeline so that pressure surges are avoided on long runs or sensitive systems.

What distinguishes modulating duty from open-close duty is the thermal and mechanical load the drive is built to carry. A modulating actuator receives a setpoint from the control system, moves in many short steps, stops, reverses and holds position, so the motor, gear stage and electronics see far more starts than an isolating device. The AUMA SQR is dimensioned for exactly this S4 – 25 % duty cycle. Paired with AUMA controls, the position setpoint can arrive as an analogue signal or over a fieldbus, and the actuator closes the loop by feeding position and status back to the control system, so a valve can be driven to a precise opening and held there with repeatable accuracy.

Engineering Design of the AUMA SQR

The housing of the AUMA SQR is built around AUMA’s modular SQ concept: a common actuator body, a motor, a gear section and a valve interface that can be combined with different controls. A handwheel for manual operation is fitted as standard so the valve can be moved during commissioning or a power failure, and a mechanical position indicator shows the valve position locally without electrical supply. The SQR is offered with 3-phase and 1-phase AC motors, and electrical connection is made through the AUMA plug/socket connector, with terminals available as an option and cable entries in different versions to suit site practice.

Valve attachments follow DIN and ISO standards, with the torque passed to the valve through a splined coupling that can be supplied unbored, with a square bore, with two flats or with a keyway. The SQR is protected to IP68 and carries the KS corrosion protection system, and it operates across an ambient temperature range of −30 °C to +70 °C, which suits both unheated outdoor stations and the high temperatures common in the Gulf. Options include intermediate position switches, switches in tandem version, a position transmitter and a magnetic limit and torque transmitter, and selected configurations can be supplied for functional safety up to SIL 2.

Key Features

The AUMA SQR brings a complete set of modulating-duty features into a single part-turn drive. The principal advantages for the plant engineer are as follows.

• Rated for modulating duty, class C, at S4 – 25 %, with up to 1,500 starts per hour for continuous process control.
• A 50 Nm to 2,500 Nm torque range, with a modulating torque range of 75 Nm to 1,200 Nm, covers a wide spread of butterfly, ball and plug valves.
• Operating time for 90 degrees is selectable from 8 s to 100 s, so valve speed can be matched to the process and to surge limits.
• Swing angle is adjustable from 75 to 105 degrees to fit the valve type and its mechanical travel.
• IP68 enclosure protection and the KS corrosion protection system provide reliable service outdoors, in humid pump stations and in dusty environments.
• A handwheel for manual operation and a mechanical position indicator keep the valve controllable and visible without electrical power.
• Options such as intermediate position switches, tandem switches, a position transmitter and a magnetic limit and torque transmitter let the actuator adapt to the control scheme.
• Combination with controls from simple OPEN-CLOSE units to micro-controlled versions with operating data logging and fieldbus interface, with SIL 2 possible for selected configurations.

Industrial Applications

In municipal and industrial water systems, the AUMA SQR regulates flow through butterfly valves on pump discharge lines, reservoir inlets and treatment plant headers, where a fixed valve position would waste energy or cause hydraulic transients. In district cooling plants and large commercial HVAC networks it modulates differential pressure and flow around chillers and heat exchangers, and in desalination and power stations it positions valves on seawater circuits, cooling water and auxiliary services. Each of these duties asks for frequent, small corrections held over years of operation, which is the reason the modulating rating matters more than the headline torque figure.

In Oman and the GCC, Seven Star LLC supplies the AUMA SQR with local technical support for projects in the Sultanate of Oman, from the industrial zones of Sohar and Salalah to utility works in Muscat and across the GCC. Because the SQR shares its mechanical interface with the AUMA SQ, SQEx and SQREx families, plants that already operate AUMA part-turn actuators can add modulating valves while keeping a uniform operating concept, common spare parts and familiar commissioning tools. Because the AUMA SQR is built on the same SQ platform as the on-off drive, a plant that standardises on the AUMA SQR for control valves can stock common spare parts, and the AUMA SQR keeps the familiar mounting dimensions of the SQ family for retrofit work. For projects that combine the AUMA SQR with other drives or controls, Seven Star LLC also supplies the AUMA SQ part-turn actuator, the AUMA SQRV and the AUMA MATIC AM/AC integral actuator controls.

Technical Specifications

The following table summarises the key data published by AUMA for the AUMA SQR .2 type range. Detailed dimensions are provided in the downloadable dimension sheet for SQ/SQR 05.2 to 14.2.

Request a Quote for AUMA SQR

To request a quotation for the AUMA SQR, send us the valve type, required torque, supply voltage and control interface and we will respond with a formal quotation. Seven Star LLC can advise on availability, lead times and the technical dimension sheet linked on this page, and our instrumentation division is available to support commissioning questions. In Oman and the GCC, we supply the devices on request to utilities, EPC contractors and plant operators. Contact us to submit your RFQ.