AUMA SA+GS Multi-Turn Actuator and Part-Turn Gearbox Combination

Overview

The AUMA SA+GS is the combination of an AUMA SA multi-turn actuator with a GS part-turn gearbox, and together they act as an electric part-turn actuator for much higher torque requirements than a standalone SQ can deliver. AUMA describes these combinations as the complement to the SQ part-turn actuators, whose range ends at 2,400 Nm. With the GS gearbox stage, the torque range extends from 250 Nm to 675,000 Nm, which brings very large butterfly valves, ball valves and plug valves within reach of the AUMA electric actuation concept, including pipeline and dam valves that were historically automated with hydraulics.

In Oman and the GCC, Seven Star LLC proudly supplies the AUMA SA+GS combination to water transmission, power generation, desalination and oil and gas operators in the Sultanate of Oman and across the GCC. The AUMA GS part-turn gearbox is also available as a stand-alone product on this site; this page covers the complete motorised assembly of SA actuator plus GS gearbox, including the selection of the correct SA size, gearbox size, controls and valve interface for the valve torque, so that buyers receive a matched, ready-to-install drive.

Operating Principle

In the AUMA SA+GS the SA multi-turn actuator provides the motor, the control unit with limit and torque sensing and the handwheel, and its output drives the input shaft of a GS part-turn gearbox. The worm gear inside the GS converts many input turns into a 90 degree output movement and multiplies the torque by the gear ratio, so a moderately sized multi-turn actuator can generate the very high torques required by large valves. The operating time for 90 degrees ranges from 9 s to 392 s, depending on the actuator speed and the gearbox ratio selected.

The worm gear of the GS is self-locking, which means that the valve position cannot be altered by the process medium or by vibration when the actuator is stationary. End stops in the gearbox define the swing angle of 100 degrees and can be modified, and for particular tasks the combination can be provided with a swing angle greater than 100 degrees, or as a multi-turn version without end stops. Because all signalling and torque or limit switching is carried out in the SA actuator, the AUMA SA+GS is operated and integrated like any other AUMA multi-turn actuator with its controls.

Engineering Design of the AUMA SA+GS

The AUMA SA+GS is a modular assembly: SA multi-turn actuator, GS gearbox and, when required, AUMA actuator controls such as AM or AC. The electrical connection uses the AUMA plug/socket connector with terminals optional, cable entries are available in different versions, and valve attachments conform to DIN and ISO standards. The handwheel is retained for manual operation, which is especially valuable on large valves where emergency manual operation must still be practical. Optional chainwheels, couplings, spigot rings and valve mounting flanges are covered by AUMA dimension sheets for the GS series.

Service conditions are demanding. Enclosure protection is IP68, corrosion protection is KS, and the ambient temperature range is −40 °C to +80 °C. The ATEX marking listed for the assembly is II 2G Ex h IIC T4 Gb and II 2D Ex h IIIC T130 °C Db, covering both gas and dust atmospheres, subject to confirmation of the exact configuration. Gearboxes can also be supplied in IP68, and for buried service or high immersion levels AUMA offers special versions on request, so the AUMA SA+GS can be specified for the chambers and underground installations common in water networks.

Key Features

The AUMA SA+GS combination is designed for valves whose torque exceeds the SQ range. Its key features are the following.

• Torque range from 250 Nm to 675,000 Nm, extending electric actuation far beyond the 2,400 Nm limit of SQ actuators.
• Operating time for 90 degrees from 9 s to 392 s for matching valve speed to the process.
• Self-locking gearbox keeps the valve position stable without power or brake.
• End stops that can be modified, with a 100 degree standard swing angle and options for larger angles or multi-turn operation.
• Handwheel for manual operation on very large valves.
• IP68 enclosure protection, KS corrosion protection and an ambient temperature range of −40 °C to +80 °C.
• ATEX explosion protection marking II 2G Ex h IIC T4 Gb and II 2D Ex h IIIC T130 °C Db.
• Electrical connection via AUMA plug/socket connector and valve attachments to DIN and ISO standards.

Industrial Applications

The AUMA SA+GS is the option for the largest valves on a site: main isolation butterfly valves on raw water and seawater intake lines, cooling-water valves in power stations, large ball and plug valves on pipelines, and dam, penstock and reservoir outlet valves. Where a project would otherwise need a large hydraulic power pack, the electric combination reduces auxiliary equipment and maintenance. The self-locking worm gear is useful on pumped and gravity systems, since the valve will not drift under flow loads once the motor stops.

In Oman and the GCC, Seven Star LLC distributes the AUMA SA+GS to customers in the Sultanate of Oman and the GCC, including large infrastructure in the Sohar and Salalah economic zones and national water projects supplying Muscat. We assist with the torque calculation, the selection of SA and GS sizes and the selection of AM or AC controls, and we can supply the AUMA GS gearbox alone for customers who already own suitable SA actuators. For projects that combine the AUMA SA+GS with other drives or controls, Seven Star LLC also supplies the AUMA GS part-turn gearbox, the AUMA SQ part-turn actuator and the AUMA MATIC AM/AC integral actuator controls.

Technical Specifications

The following table lists the key data published by AUMA for the AUMA SA+GS combination. The downloadable AUMA modular range brochure describes the SA/GS part-turn combinations in detail.

Request a Quote for AUMA SA+GS

To request a quotation for the AUMA SA+GS, send us the valve type and size, maximum torque, operating time, supply voltage and control requirement. Seven Star LLC will return a formal RFQ response covering the SA actuator, GS gearbox and controls, with stock and lead-time information and the brochure linked on this page. In Oman and the GCC, we supply the equipment on request, and our instrumentation division supports torque calculations and commissioning questions.