AUMA GS 100.3 Part-Turn Worm Gearbox (4,000 Nm)

Overview

AUMA GS 100.3 is the first GS size that offers five distinct reduction ratios, from 52:1 to 208:1, and it handles up to 4,000 Nm of valve torque in open-close duty. That makes it the workhorse for large butterfly valves, ball valves and plug valves in water transmission and process plants, where a 4,000 Nm quarter-turn valve is common but a 28,000 Nm one is not. The same casting carries two different internal builds: the two lower ratios are plain worm gearings weighing 33 kg, while the three higher ratios add primary reduction or planetary gearing to cut the torque that the actuator must supply, at a weight of 39 kg.

Seven Star LLC, the official trusted supplier and regional supplier for AUMA, supplies the AUMA GS 100.3 across the Sultanate of Oman and the GCC.

Operating Principle of the AUMA GS 100.3

The AUMA GS 100.3 uses a worm and worm wheel set whose output coupling rotates the valve through a swing of up to 90 degrees. The standard housing is cast iron with a spheroidal cast iron worm wheel, and the output has an integrated spigot flange for EN ISO 5211 attachment from GS 160.3 upward, while on the AUMA GS 100.3 spigots are realised through spigot rings. The gearbox is self-locking at standstill, and positive end stops formed by a travelling nut let the swing angle be set precisely at the gearbox rather than only by actuator limit switches.

The 52:1 ratio needs 13 turns for 90 degrees and has a conversion factor of 18.7; at 107:1 the factor is 22.6 with 26.8 turns and a 2,800 Nm limit because of the toothing. The primary-reduced ratios use factors of 42.8 (126:1), 54.0 (160:1) and 71.0 (208:1) with 31.5, 40 and 52 turns, so a 4,000 Nm valve needs only 93, 74 or 57 Nm of input torque instead of 214 Nm at 52:1. End stop strength for input side operation follows the same pattern, at 1,350 Nm for 52:1, 625 Nm for 126:1, 500 Nm for 160:1 and 250 Nm for 208:1.

Engineering Design of the AUMA GS 100.3

Valve attachment is by flanges F14 and F16 according to EN ISO 5211 with a maximum shaft diameter of 80 mm, and the input shaft is 30 mm or 20 mm depending on the ratio. The input mounting flange is F14 (F10 optional) for the direct ratios and F10 for the primary-reduced ratios, which means a multi-turn actuator with an F14 input flange can drive the 52:1 version while an F10 actuator such as the SA 10.2 drives the 126:1, 160:1 and 208:1 versions. The gearbox may be mounted in any position, and a 90-degree deflection of the input shaft is possible through a GK bevel gearbox mounted directly on the GS or on the planetary stage.

Protection is IP68 with KS corrosion protection and a double-layer powder coating in AUMA silver-grey, and the ambient range is -40 to +80 degrees Celsius with low-temperature and high-temperature options. Duty class 2 raises the permissible valve torque to 5,000 Nm for infrequently operated valves, and duty class 3 for manual operation reaches 6,000 Nm with handwheel diameters from 250 to 800 mm. For ATEX service the mean output torque over three OPEN-CLOSE-OPEN cycles is 2,000 Nm, or 1,400 Nm on the 107:1 ratio.

Reduction Ratio Options of the AUMA GS 100.3

Each ratio of the AUMA GS 100.3 trades operating time against input torque, and the table summarises the duty class 1 values from the AUMA data sheet.

The 107:1 ratio is limited to 2,800 Nm, every other ratio supports 4,000 Nm, and the 126:1, 160:1 and 208:1 ratios are flagged by AUMA as equipped with primary reduction gearing.

Key Features

The AUMA GS 100.3 is selected where valve torque approaches 4,000 Nm and the choice of ratio decides the actuator size:

• Maximum valve torque of 4,000 Nm in duty class 1, 5,000 Nm in duty class 2 and 6,000 Nm for manual operation.
• Five reduction ratios from 52:1 to 208:1 with factors from 18.7 to 71.0 for fine matching of actuator torque.
• Primary reduction or planetary gearing on the 126:1, 160:1 and 208:1 ratios cuts input torque to 93, 74 and 57 Nm.
• Valve flanges F14 and F16 to EN ISO 5211 and output shafts up to 80 mm diameter.
• Fastest operating times from 7 seconds at 52:1 up to 19 seconds at 208:1 based on AUMA’s permitted input speeds.
• Weight of 33 kg for the direct ratios and 39 kg for the primary-reduced ratios.
• Lifetime of 5,000 cycles at maximum torque in duty class 1, shared with the GS 80.3.
• Optional 90-degree input shaft deflection with a GK bevel gearbox for restricted installation space.

Industrial Applications

Large-diameter butterfly valves on seawater intake lines, cooling water circuits and fire-water ring mains frequently need the 4,000 Nm range of the AUMA GS 100.3. At a coastal desalination plant in the Sultanate of Oman, the 126:1 or 160:1 version lets a mid-sized SA 10.2 operate a heavily seated valve without moving to the next actuator frame, while the 52:1 version suits large ball valves that must close in under ten seconds. Gas-processing skids and refinery utility headers around Sohar use the same size on plug valves where fast, repeatable positioning is required.

In Oman and the GCC, Seven Star LLC supplies the AUMA GS 100.3 and its matching SA or SAR multi-turn actuators to EPC contractors and municipal utilities across Oman and the GCC, including projects in Salalah and Duqm. See also the AUMA GS part-turn gearbox range, the AUMA SAR 14.1 modulating actuator for modulating duty and the AUMA GST spur gearbox family for multi-turn valves.

Related pages on our site: AUMA GS 63.3, AUMA GS 160.3 and AUMA GK bevel gearbox.

Technical Specifications

AUMA publishes the GS 50.3 to GS 250.3 data as one multi-size sheet, so only the AUMA GS 100.3 rows are reproduced here, with the primary-reduced ratios flagged as AUMA does.

Only the 52:1 ratio and the primary-reduced ratios carry the full 4,000 Nm, while 107:1 stops at 2,800 Nm, so settle the ratio first and size the multi-turn actuator from the 214 Nm input torque of the 52:1 ratio downward.

Request a Quote for AUMA GS 100.3

To order the AUMA GS 100.3, submit an RFQ listing the maximum valve torque, the required closing time, the EN ISO 5211 flange and the supply frequency of the actuator. Seven Star LLC will propose the ratio, confirm the actuator pairing and attach the AUMA technical data sheet, which you can also download from this page. Our instrumentation division in Muscat handles quotation, delivery to site and technical advice as a supplier of AUMA products in Oman and the GCC.