Overview

The document details the AT Series quarter-turn worm gear operators designed for manual valve actuation and industrial applications. It covers technical specifications, materials, design features, performance data, and customization options, emphasizing robustness, reliability, and adaptability to various environments.

Material Options and Environmental Adaptations

• Housing materials: ductile iron, carbon steel, stainless steel.
• Corrosion-resistant components: stainless steel worm shaft, fasteners, handwheel.
• Worm wheel options include aluminum bronze for enhanced durability.
• Temperature range suitability: from -52°C (-61.6°F) to +200°C (+392°F).
• Marine-grade versions with all exposed parts in stainless steel.
• Protection standards: IP-67 standard enclosure, IP-68 available on request.
• Additional options: padlock arrangements, Namur mounting for limit switch boxes, extension shafts for buried service.
• Finish options: painting and powder coating for corrosion protection and aesthetics.

Design Features

• Robust, lean design optimized for less critical applications.
• Available in 27 models with torque ratings up to 350,000 Nm and F-60 mounting base.
• Grease-filled, fully sealed gearing for maintenance-free operation.
• Cast iron casing and ductile iron quadrant for durability.
• Adjustable stroke from 0-90° plus an additional +5°.
• Standard zinc plated fasteners with epoxy primer coating; powder coated handwheels for smooth manual operation.
• Top-mounted and top-operated versions for handwheel, chainwheel, or electric actuator integration.
• Twin-shaft versions reduce manual turns on larger models.
• Stainless steel versions for corrosive and sanitary environments.
• API 6D compliant gearboxes available up to 3500 Nm torque.
• Part-turn 180° gearboxes available up to 15,000 Nm torque.

Performance Specifications and Model Data

• Output torque range: 250 Nm to 350,000 Nm.
• Mechanical advantage ratios: 8:1 to 11,284:1 depending on model.
• Turns to close: from 8.25 to over 2800 turns for largest models.
• ISO 5211 mounting flange sizes: F05 to F60.
• Drive bore diameters: 20 mm to 260 mm.
• Unit weights: 2.7 kg to over 385 kg.
• Recommended handwheel diameters: 20 mm to 80 mm.

Figures categorize models by size (up to AT-90 and above AT-90) with dimensional and mounting details.

Materials and Components

• Housing and covers: Cast iron ASTM A48-83 (FG 200).
• Worm: AISI 1040 carbon steel.
• Worm wheel: Ductile iron ASTM A70-50-05 or aluminum bronze option.
• Input shaft: Carbon steel A576-1045.
• Spur gears and pinions: Carbon steel and ductile iron.
• Thrust bearings: Special steel ASTM A295 52100.

Additional Options and Customizations

• Stainless steel versions for corrosive and sanitary environments.
• Padlock arrangements for enhanced security.
• Namur mounting for limit switch box integration.
• Extension shafts for buried service applications.
• Finish painting and powder coating for protection and aesthetics.

Performance Specifications - Detailed Technical Data

• Component materials: Worm wheel (AISI 1040), input shaft (AISI 1040 / AISI 5120), gearbox housing and covers (FG 200 cast iron), worm (AISI 4140 steel), spur gear components (ASTM A536 80-55-06 cast iron), thrust bearings (standard industrial bearings).
• Gearbox sizes: Ø250, Ø350, Ø500, Ø600, Ø750, Ø900, Ø1000.
• Output torque range: 10 Nm to 50,000 Nm depending on model.
• Gear ratios: Approximately 22:1 up to 11,284:1.
• Mechanical advantage tolerance: ±10%.
• Turns to close: 2.7 to 75 turns depending on size and ratio.
• Unit weights: Approximately 20 kg to over 250 kg.
• Mounting: ISO 5211 compliant flanges and drive bores (12 mm to 45 mm).
• Handwheel sizes recommended per model.
• Design emphasizes durability with alloy steels and cast iron, standard thrust bearings for axial loads, and efficient worm/worm wheel torque transmission.
• Includes detailed dimensional data and performance curves for assembly and installation.
• References Emerson model numbers and part codes for ordering.
• Document revision dated April 9, 2015.

Summary

The AT Series quarter-turn worm gear operators provide a comprehensive range of manual gearboxes suitable for diverse torque requirements and environmental conditions. Their robust construction, material versatility, and compliance with industry standards make them ideal for manual valve operation in industrial, marine, and sanitary settings. Detailed performance and dimensional data facilitate precise selection, installation, and maintenance by engineers and technicians.