AUMA GK Bevel Gearbox (Multi-Turn)
Overview
The AUMA GK is a range of bevel gearboxes for motor or manual operation of valves such as gate valves and globe valves. According to ISO 22153, a multi-turn gearbox transmits torque to the valve for at least one revolution and must withstand thrust; the GK range does this while displacing the effective direction by 90 degrees and considerably multiplying the output torque. The range covers sizes GK 10.2, GK 14.2, GK 14.6, GK 16.2, GK 25.2, GK 30.2, GK 35.2 and GK 40.2 with maximum valve torques from 120 Nm up to 16,000 Nm.
In Oman and the GCC, Seven Star LLC proudly supplies the AUMA GK to customers across the Sultanate of Oman and the wider GCC. We assist customers in Oman and the GCC with sizing, from valve torque and reduction ratio to flange and input shaft.
Working Principle of the AUMA GK
Inside the AUMA GK, a pair of bevel gears with face-hobbed Palloid teeth transmits the rotation of the input shaft to the output drive sleeve at a right angle. Reduction ratios between 1:1 and 22:1 are available, and each ratio has a conversion factor from output torque to input torque that is used to size the motor or handwheel; for new gearboxes AUMA recommends adding 15 % to the input torque because of the lower efficiency of the run-in gear set. Sizes GK 10.2 to GK 25.2 use a single stage, while GK 30.2 to GK 40.2 use a double-stage design for the higher reduction ratios.
Because the Palloid tooth geometry is manufactured for smooth meshing, the AUMA GK runs with low noise and high efficiency, and AUMA multi-turn gearboxes meet or exceed the lifetime requirements of EN 15714-2. In potentially explosive atmospheres the AUMA datasheet lists the T4 / T130 °C marking for ambient ranges of −40 °C to +40 °C, −40 °C to +60 °C and −60 °C to +60 °C, while the −40 °C to +80 °C range quoted for the standard version corresponds to an optional T3 / T190 °C marking when used in hazardous areas. The output drive is designed for the thrust loads of rising-stem valves and can be fitted with a stem nut to work as a screw jack, a stem protection tube for rising stems, and optional position and end position signalling during manual operation.
Engineering Design of the AUMA GK
The AUMA GK input shaft is made of stainless steel and is cylindrical with a parallel key to DIN 6885.1 as standard; a tapered or cylindrical square for power tool adapters is an option. Valve attachments follow EN ISO 5210 with flanges F10 to F40 (DIN 3210 G0 to G7), and output drive types A, B1, B2, B3 and B4 are available, along with several special attachments. The gearbox can be mounted in any position, withstands ambient temperatures of −40 °C to +80 °C as standard, and has low-temperature and high-temperature versions for −60 °C to +60 °C and 0 °C to +120 °C.
Enclosure protection is IP68 (up to 8 m head of water for a maximum of 96 hours), the double-layer iron-mica powder coating provides KS corrosion protection with KX available for extremely saline or polluted environments, and the standard colour is AUMA silver-grey. For motor operation the gearbox accepts SA and SAR multi-turn actuators through standard input flanges up to a permissible actuator weight of 300 kg, with a maximum input speed of 240 rpm. For manual duty an aluminium handwheel with ball handle in sizes up to 800 mm is available, with a lockable version and a WSH limit switching device as options.
Key Features
The AUMA GK combines robust mechanics with flexible mounting:
- Right-angle bevel gearing that moves the operating axis by 90 degrees and multiplies the torque of an actuator or handwheel.
- Sizes from GK 10.2 to GK 40.2 cover maximum valve torques from 120 Nm to 16,000 Nm with reduction ratios from 1:1 to 22:1.
- Face-hobbed Palloid gearing delivers low-noise, efficient operation and long service life.
- Stainless steel input shaft and double-layer powder coating resist corrosion in coastal and industrial atmospheres.
- Valve attachments according to EN ISO 5210 with output types A, B1 to B4 and several special forms.
- Suitable for manual operation with handwheels or electrical operation with AUMA SA multi-turn actuators.
- Options include stem nut for screw jack use, stem protection tube, position signalling during manual operation, high and low temperature versions and an oxygen-service version.
- ATEX approval (II2G Ex h IIC T4 Gb, II2D Ex h IIIC T130 °C Db) and functional safety up to SIL 2 in selected configurations.
Industrial Applications
Bevel gearboxes are used wherever an actuator or handwheel must be placed beside the valve rather than above it, or where more torque is needed than a multi-turn actuator can supply directly. The AUMA GK is therefore common on large gate valves and globe valves in water transmission lines, desalination plants and pump stations around Muscat, on isolation valves in refineries and gas facilities at Sohar and Duqm, and on valves in confined pipe galleries or pits where a vertical stem would collide with structure or equipment. Its ATEX approval makes it suitable for classified areas.
In Oman and the GCC, Seven Star LLC supplies the AUMA GK with matching SA multi-turn actuators, handwheels, stem protection tubes and floor pedestals for projects across the Sultanate of Oman and the GCC, including power plants and utility networks in the Salalah and Sohar economic zones. When reviewing the AUMA GK against the rest of the AUMA range, engineers often also look at the AUMA SA and GK, the AUMA GST spur gearbox and the AUMA GP.
Technical Specifications
The table lists the principal data of the AUMA GK range from the AUMA technical data sheet, which can be downloaded from this page.
| Parameter | Specification |
|---|---|
| Model | AUMA GK 10.2, GK 14.2, GK 14.6, GK 16.2, GK 25.2, GK 30.2, GK 35.2, GK 40.2 |
| Max. valve torque | 120 Nm (GK 10.2) up to 16,000 Nm (GK 40.2) |
| Reduction ratios | 1:1 to 22:1 depending on size |
| Valve attachment | EN ISO 5210 flanges F10 to F40 (DIN 3210 G0 to G7); output types A, B1–B4 |
| Weight | Approx. 8.5 kg (GK 10.2) to 250 kg (GK 40.2) |
| Stages | Single stage GK 10.2–25.2; double stage GK 30.2–40.2 |
| Type of duty | Short-time duty S2 – 15 min; intermittent duty S4 – 25 % (modulating) |
| Motor operation | AUMA SA/SAR multi-turn actuators; max. input speed 240 rpm |
| Ambient temperature | −40 °C to +80 °C; options −60 °C to +60 °C and 0 °C to +120 °C |
| Enclosure / corrosion protection | IP68 / KS (KX optional) |
| Explosion protection | II2G Ex h IIC T4 Gb; II2D Ex h IIIC T130 °C Db (ATEX option) |
Request a Quote for AUMA GK
Request a formal quotation for the AUMA GK by submitting an RFQ with the maximum valve torque, the EN ISO 5210 flange, the reduction ratio you need and the SA or SAR actuator, or handwheel, you plan to mount. Seven Star LLC will confirm the GK size and ratio from the valid combinations in the technical datasheet that you can download from this page. In Oman and the GCC, we supply gearboxes on request with local technical support from Muscat.
- Datasheet AUMA GK 10.2 - GK 40.2 Technical Data Sheet Download
AUMA actuator and gearbox types
SA multi-turn actuators handle open-close duty on gate and globe valves, and SAR is the modulating version; the listing includes the SA 07.2, SA 10.2 and SA 25.1. SAEx and SAREx are the explosion-proof equivalents. Part-turn duty on ball and butterfly valves is covered by SQ and the modulating SQR, or by an SA actuator combined with a GS part-turn gearbox. LE linear thrust units convert multi-turn output to thrust, and GHT multi-turn gearboxes extend the torque range up to 120,000 Nm. PROFOX is the compact actuator line. Special items include the seawater-resistant SGM and SGMR part-turn actuators with bronze housings, the SVC and SVCR globe valve actuators and the FQM fail-safe unit. Integral controls come as AM or AC versions.Where AUMA electric actuators are used
AUMA actuators are found in water, power, oil and gas, marine and general industry. In practice that means isolation and control valves in water treatment and pumping stations, power plant steam and cooling systems, tank farms and pipelines, and sluice gates and dampers.Ordering AUMA actuators and parts: what we need
For a replacement send photos of the actuator, motor and controls nameplates: type, order number, serial number and wiring diagram number. For a new actuator we need:- valve type, required torque or thrust, and turns or stroke
- valve mounting flange and stem or shaft details
- output speed, duty (open-close or modulating)
- supply voltage and frequency, control signals or fieldbus
- enclosure protection, ambient temperature, Ex requirement
Browse AUMA products by category: Valve Actuator, Industrial Communications.
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