AUMA SA 14.2 Multi-Turn Actuator

Overview

AUMA SA 14.2 is an AUMA NORM multi-turn actuator for open-close duty with a tripping-torque window of 100 to 250 Nm and 12 output speeds from 4 to 180 rpm. SA 14.2 is the first SA size on the F14 flange. With a tripping-torque window of 100 to 250 Nm it covers the valves that are too stiff for the SA 10.2 but do not yet justify the 200 to 500 Nm SA 14.6, and its 315 mm handwheel gives the operator real leverage for emergency manual operation.

Seven Star LLC supplies AUMA products across Oman and the GCC, and supplies the AUMA SA 14.2 with technical support from Muscat.

Operating Principle

Motor turns are counted by a limit mechanism in the SA 14.2, which stops the stroke at OPEN and CLOSED and trips independently on torque in either direction, adjustable from 100 to 250 Nm. Duty is S2 – 15 min as standard, S2 – 30 min as an option, and the unit is self-locking up to 90 rpm.

Engineering Design of the AUMA SA 14.2

At 180 rpm the S2-15 min torque drops to 200 Nm and the S2-30 min value to 140 Nm, so very short stroking times cost torque. If the valve needs close to 250 Nm, select a speed of 125 rpm or lower, and remember that the actuator is self-locking only up to 90 rpm at 50 Hz.

Key Features

What stands out on the SA 14.2:

• Mid-range multi-turn actuator for medium gate and globe valves.
• Torque switches can be set from 100 up to 250 Nm, giving a 2.5:1 adjustment span.
• At 180 Nm the S2 – 30 min figure sits at 72 percent of the highest tripping torque.
• Dividing the top torque by the quoted weight gives 5.2 to 5.7 Nm/kg.
• An illustrative stroke of 30 turns takes about 56.2 seconds at 32 rpm.
• Smaller loads belong to the SA 10.2; larger ones move up to the SA 14.6.
• Separate AUMA documents list the dimensions and the electrical data.

Selecting the AUMA SA 14.2

Moving from the SA 10.2 to the SA 14.2 changes several things at once: the flange grows from F10 to F14, the rising-stem capacity from 40 mm to 58 mm, the handwheel from 200 mm to 315 mm, and the weight from about 22 to 25 kg to about 44 to 48 kg. Plan lifting and bracket design accordingly. Within the 100 to 250 Nm window the lower limit matters as much as the upper: valves whose seating torque is only 60 to 80 Nm should stay on the SA 10.2, because the AUMA SA 14.2 cannot be set below 100 Nm.

Typical partners are medium gate valves, large globe valves and stop-check valves, pump-discharge isolation valves, cooling-water and fire-water header valves, and rising-stem sluice gates of moderate size. Wedge-gate valves at higher differential pressure usually land in this torque class once packing friction is added.

Medium gate valves in cooling-water service often look simple but hide two torque peaks: unseating at the start of the opening stroke and wedging at the end of the closing stroke. On the AUMA SA 14.2 the torque switch for each direction is set independently, so the opening switch can be set close to the unseating peak while the closing switch protects the wedge. Where the valve is a wedge gate, ending the closing stroke on torque rather than on the limit switch is normally the right choice, and the limit switch is then set slightly earlier to signal the closed position to the control system.

Sizing example for the AUMA SA 14.2

Take an illustrative wedge-gate valve with a measured breakaway torque of 150 Nm and a running torque of 90 Nm. A 25 percent allowance on the breakaway value gives about 190 Nm, which sits within the 100 to 250 Nm window of the AUMA SA 14.2. A 30-turn stroke at 16 rpm takes about 113 seconds and at 45 rpm about 40 seconds. If the same valve were fitted with the SA 14.6, the minimum tripping torque of 200 Nm would already exceed the 190 Nm target, which is why the smaller frame is the more precise match. These numbers are an illustrative calculation and not AUMA data.

Installation and Mounting of the AUMA SA 14.2

At 44 to 48 kg the AUMA SA 14.2 is a two-person lift at most, but a lifting eye or hoist is advisable on elevated valve platforms. The F14 flange and 58 mm stem bore accept most medium valve yokes without adapters. The 315 mm handwheel needs swing clearance, so check the distance to pipework and cable trays before fixing the valve orientation, and orient the cable entries downward to stop water running along the cable into the housing.

Industrial Applications

Applications in the Sultanate include seawater cooling circuits at power and desalination plants, pump-station discharge valves on the water-transmission network, process-water headers in refineries and LNG-related utilities, and chilled-water risers in large commercial and hospital developments. In the Salalah free zone and the Duqm industrial area the AUMA SA 14.2 is a common choice for utility isolation valves that must be remotely operated yet remain manually operable during a power cut.

For pump stations and cooling circuits, Seven Star LLC can combine the SA 14.2 with the AUMA SA 10.2 multi-turn electric actuator, the AUMA MATIC AM/AC integral actuator controls and the AUMA SAEx explosion-proof actuator.

Neighbouring sizes and counterparts: AUMA SA 10.2 multi-turn actuator.

Technical Specifications

Data of the AUMA SA 14.2 from the AUMA technical data sheet for 3-phase AC motors.

Setpoint guide for the SA 14.2 (illustrative calculation, not AUMA data)

Stroking time for 30 turns at the SA 14.2 (illustrative calculation, not AUMA data)

Request a Quote for AUMA SA 14.2

Send Seven Star LLC your valve torque, the F14 interface details and the controls you prefer, and a quotation for the AUMA SA 14.2 follows. The AUMA datasheet is available through the download link on this page.