AT Series
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Quarter-turn Worm Gear Operators for Manual Operation Description • Lean design whilst optimizing robustness and strength • Used for less critical applications • 27 models up to a torque of 350,000 Nm and F-60 mounting base • Grease filled for life • Fully sealed gearbox and completely enclosed gearing • Cast iron casing and ductile iron quadrant • Stroke 0-90° (+5° adjustable) • Zinc plated fasteners • High performance axial bearings • Epoxy primer coating is standard for gearbox • Powder coated handwheels for smooth and easy operation Features • Housing material options (ductile iron / carbon steel / stainless steel) • Worm shaft, fasteners and hand wheel material option available in stainless steel • Worm wheel material option available in aluminum bronze • High temperature variant up to +200°C (+392°F) & low temperature variant up to -52°C (-61.6°F) available • Marine application (all exposed shafts and fasteners in stainless steel) • Finish painting is available on request • IP-67 standard enclosure (IP-68 available on request) • Padlock arrangement option available • Namur mounting option available for limit switch box fitment • Extension shaft for buried service available Options • Top mounted / top operated version (“handwheel, chainwheel or electric actuator” to be mounted / operated from the top of the gearbox and not from the side) of AT-IS, CW and IS-EA series (all models) • Twin-shaft version available for some models of AT and AT-IS series to reduce no. of turns to close for manual operation (for models above AT-300/2/S3 and AT-300/1/S3-IS) • Stainless steel version of gearboxes available for applications in highly corrosive environments as well as food and beverage, pharmaceutical and sanitary facilities. Option available for all models of AT, AT-IS, IS-EA and CW series • Gearbox options as per API 6D specifications available for torques up to 3500 Nm • Part

1. SPUR PINION AISI 4140G SR. 7. SPUR COVER FG 200 JO REFER FIG (2) FOR MODELS ABOVE- 3. W THRUST BEARING STD B G 2. G ASTM A536 SPUR GEAR View From Top At Close Position Note: Refer to Figure (1) for Models up to “AT-90” Refer to Figure (2) for Models above “AT-90” H REFER FIG (2) FOR MODELS ABOVE-AT 90 F 46 20 176 ATIONS 'AT SERIES' (Quarterturn Manual Operation) Ø600 APPROX RECOMMENDED UNIT HANDWHEEL WEIGHT (mm) (Kg) RATED OUTPUT TORQUE (Nm) Quarter-turn Worm Gear Operators for Manual Operation EMERSON MODEL REFER FIG (2) FOR MODELS ABOVE PERFORMANCE SPECIFICATIONS 'AT SERIES'...