AUMA SAR 14.6 Modulating Multi-Turn Actuator

Overview

AUMA SAR 14.6 is an AUMA NORM multi-turn actuator for modulating duty (class C, ISO 22153) with a tripping-torque window of 250 to 500 Nm and 10 output speeds from 4 to 90 rpm. SAR 14.6 extends the F14 modulating range to 250 to 500 Nm tripping torque and up to 200 Nm of modulating torque at S4-25 percent. It is fitted with a 400 mm handwheel and quoted at 46 to 53 kg.

Seven Star LLC supplies the SAR 14.6 as trusted AUMA supplier across Oman and the GCC, with genuine factory documentation and technical support from Muscat.

Operating Principle

The SAR 14.6 is driven in short pulses by an AM or AC positioner. Modulating torque is 200 Nm (S4 – 25 percent) at 4 to 22 rpm, 175 Nm at 32 to 45 rpm and 150 Nm at 63 to 90 rpm, and the actuator holds position by self-locking.

Engineering Design of the AUMA SAR 14.6

Starts per hour are limited to 1,200 at the lowest speeds, falling through 900 and 600 to 400 at the highest speeds, with a minimum pulse of 70 ms and reversal times of 80 to 280 ms. Check the valve’s running torque against the modulating column, not against the tripping torque.

Key Features

Points to weigh when specifying the AUMA SAR 14.6:

• Modulating F14 multi-turn actuator, 250 to 500 Nm.
• The setting range runs from 250 to 500 Nm, so the largest setting is 2.0 times the smallest.
• Rated S4 – 50 percent torque of 360 Nm corresponds to 72 percent of the 500 Nm tripping maximum.
• Weight-specific torque comes to roughly 9.4 to 10.9 Nm/kg.
• An illustrative stroke of 35 turns takes about 95.5 seconds at 22 rpm.
• Its closest relatives in the range are the SAR 14.2 and the SAR 16.2.
• Request the separate AUMA dimension and electrical data sheets when planning the installation.

Selecting the AUMA SAR 14.6

Against the SAR 14.2, the SAR 14.6 offers the same F14 flange and 58 mm stem capacity but a larger handwheel, a doubled torque class and a modulating torque of 200 Nm instead of 120 Nm. Modulating torque is 200 Nm (S4-25 percent) and 180 Nm (S4-50 percent) at the lower speeds, falling to 150 Nm and 105 Nm at the highest speeds, so the usable torque margin for loop-controlled positioning should be read from the actual speed selected. The minimum tripping torque of 250 Nm excludes light valves.

Typical partners are large control globe valves, modulating wedge-gate valves, steam conditioning and attemperation valves with high differential pressure, and large rising-stem valves in feed-water control.

Heavy control valves for steam and high-pressure water develop strongly varying torque over the stroke, and the highest running torque often appears near the seat where the plug is throttling at high differential pressure. For the AUMA SAR 14.6 the 200 Nm modulating limit at S4-25 percent applies to the average load during modulation, while the torque switches protect against peaks up to 500 Nm. If the valve data sheet lists a maximum running torque near 200 Nm, consider S4-50 percent derating or the next frame size, because continuous operation near the limit shortens motor life in hot plant rooms. Verify during commissioning that the position feedback is calibrated over the whole travel and that the torque switches are set above the highest running torque observed, which keeps nuisance trips away while still protecting the valve from a jammed condition.

Sizing example for the AUMA SAR 14.6

Consider an illustrative valve that needs 170 Nm running torque and 420 Nm at the seat. The running torque is below the 200 Nm modulating limit at S4-25 percent for the lower speeds, and the seat torque is inside the 250 to 500 Nm window of the AUMA SAR 14.6. At the highest speeds the modulating limit drops to 150 Nm, which would be exceeded, so a moderate speed is again the right choice. A 30-turn stroke at 16 rpm takes about 113 seconds and at 32 rpm about 56 seconds. These numbers are an illustrative calculation and not AUMA data.

Installation and Mounting of the AUMA SAR 14.6

At 46 to 53 kg the AUMA SAR 14.6 needs a hoist for installation on elevated valves. The F14 flange and 58 mm stem match the SAR 14.2 and the SA 14.6, but the 400 mm handwheel needs more space than the smaller one. Specify AUMA MATIC AM or AUMATIC AC controls, and an analogue position transmitter if the plant control system needs a position feedback signal.

Industrial Applications

Common Omani uses are boiler feed-water control at power and desalination plants, high-pressure water-injection flow control and large seawater flow-control valves. The AUMA SAR 14.6 is also a typical replacement choice when an older SAR 14.5 type with a 250 to 500 Nm range has to be exchanged.

For related projects, a trusted supplier of AUMA products Seven Star LLC offers the AUMA SAR 14.1 multi-turn actuator, the AUMA MATIC AM/AC integral actuator controls and the AUMA SAREx explosion-proof modulating actuator in Oman and the GCC.

Neighbouring sizes and counterparts: AUMA SAR 14.2 modulating actuator, AUMA SAR 16.2 modulating actuator and AUMA SA 14.6 multi-turn actuator.

Technical Specifications

Data of the AUMA SAR 14.6 from the AUMA technical data sheet for 3-phase AC motors.

Setpoint guide for the SAR 14.6 (illustrative calculation, not AUMA data)

Stroking time for 35 turns at the SAR 14.6 (illustrative calculation, not AUMA data)

Request a Quote for AUMA SAR 14.6

Ask Seven Star LLC for a quotation on the AUMA SAR 14.6, naming valve, torque and controls. The AUMA datasheet can be downloaded from this page.