AUMA GS Part-Turn (Quarter-Turn) Gear Boxes

Overview: High-Torque Solution for Large Part-Turn Valves

The AUMA GS Part-Turn Gearbox is a worm gear reducer used for the operation of part-turn and special valves – butterfly valves, ball valves, dampers, and flue gas dampers – where torque requirements exceed what the standard SQ part-turn actuator range can deliver on its own. Combined with an AUMA SA multi-turn actuator, the GS gearbox forms a high-torque electric part-turn actuator reaching nominal torques up to 675,000 Nm, complementing the SQ range (limited to 2,400 Nm) for the largest part-turn valve applications.

As an authorized supplier of AUMA valve gearboxes, Seven Star LLC sources and supplies the GS part-turn gearbox to power plants, large water infrastructure projects, and heavy process industries across Oman and the wider GCC. Because large-diameter butterfly and ball valves in major pipelines and dampers demand torque levels far beyond typical part-turn actuators, Seven Star LLC helps engineering teams specify the correct GS gearbox size and reduction ratio for these demanding applications.

Working Principle: Worm Gear Torque Multiplication with Self-Locking

The GS gearbox uses a worm wheel and worm shaft as its core components, providing high gear reduction within a single gear stage while delivering an important self-locking effect that prevents valve position displacement if external forces act upon the closing element – a critical safety characteristic for large valves subject to flow-induced torque reversal. The worm wheel is made of spheroidal cast iron as standard, with certain applications requiring alternative materials depending on duty and environment.

End stops use a traveling nut principle in accordance with AWWA C504, providing precise, adjustable limits for the swing angle, which can range from 0° to 190° or be configured for multi-turn operation without end stops entirely. The gearbox can be operated either manually via handwheel directly, or by motor operation using a combined AUMA electric multi-turn actuator, giving plant operators both emergency manual control and automated electric operation from the same gearbox platform.

Engineering Design of the GS Gearbox

The GS gearbox housing is made of cast iron as standard, with AUMA recommending spheroidal cast iron housings where extreme external loads must be considered. All parts within the power drive are subjected to thermal hardening treatment, and the gearbox output drive conforms to ISO standard flange dimensions for compatibility with standard valve mounting. The gearbox is available with or without primary reduction gearing, and features a 360° worm wheel to support the full range of swing angle and multi-turn configurations.

Rated to IP68 protection with high-quality corrosion protection, the GS gearbox operates across an exceptionally wide ambient temperature range of -60°C to +120°C, supporting installations from arctic to extreme desert climates. When combined with an SA multi-turn actuator, the assembly is supplied in enclosure protection IP68-3, and reduction ratios spanning 39:1 to 3,328:1 allow the gearbox to be matched precisely to the actuator size and valve torque requirement.

Key Features

The AUMA GS Part-Turn Gearbox delivers high-torque quarter-turn valve automation beyond standard actuator limits. Key characteristics include:

• Torque capacity up to 675,000 Nm when combined with an AUMA SA multi-turn actuator.
• Reduction ratios from 39:1 to 3,328:1 to match actuator size and valve torque requirement.
• Swing angle from 0° to 190°, or configurable for multi-turn operation without end stops.
• Self-locking worm gear design prevents valve position displacement from external forces.
• IP68 protection with high-quality corrosion protection across -60°C to +120°C ambient range.
• End stops with traveling nut principle per AWWA C504; ISO-standard output drive.
• Manual handwheel operation or motor operation via combined AUMA multi-turn actuator.

Industrial Applications

The GS gearbox is deployed wherever large butterfly valves, ball valves, or dampers require torque beyond the reach of standard part-turn actuators, including major pipeline isolation valves, power plant flue gas dampers, water infrastructure projects with large-diameter valves, and industrial process lines with high-torque quarter-turn valve requirements. Its self-locking characteristic makes it particularly suited to applications where flow-induced torque reversal must not be allowed to displace valve position.

Seven Star LLC supports power generation engineering teams, water authorities, and heavy industrial plant operators across Oman, Muscat, Sohar, and the broader GCC region with sourcing of AUMA GS part-turn gearboxes, helping projects automate their largest, most demanding quarter-turn valves.

Technical Specifications

The table below summarizes the core specifications of the AUMA GS Part-Turn Gearbox as supplied by Seven Star LLC.

Call To Action

Seven Star LLC supplies the AUMA GS part-turn gearbox with full manufacturer documentation and regional technical support. Contact our instrumentation and valve automation division for a formal RFQ, to confirm the correct gearbox size and reduction ratio for your large-torque valve 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.