AT Stainless Steel Piston-Type Rack-and-Pinion Pneumatic Actuator

AT Stainless Steel Piston-Type Rack-and-Pinion Pneumatic Actuator
I. Product Overview
The AT stainless steel piston-type pneumatic actuator is a high-end, corrosion-resistant rack-and-pinion pneumatic drive unit. Featuring all-stainless-steel pistons and a precision rack-and-pinion transmission structure, it differs from standard aluminum-piston actuators by offering advantages such as complete corrosion resistance, moisture resistance, acid/alkali resistance, long service life, and stable operation. Driven by clean compressed air, it converts linear piston motion into 90° rotary torque. It is specifically designed for quarter-turn valves—such as ball valves, butterfly valves, and plug valves—to enable automated on/off switching and proportional control.
Available in two configurations—double-acting (AT-D) and single-acting spring-return (AT-S)—this product fully complies with ISO5211 and NAMUR international standards. It supports the direct mounting of solenoid valves, limit switches, smart positioners, and manual override mechanisms. It is widely used in demanding environments characterized by high humidity and high corrosion, such as chemical processing, coastal areas (salt spray exposure), and wastewater treatment, as well as in explosion-proof applications.
II. Model Designation and Structure
2. AT: Rack-and-pinion piston-type pneumatic actuator
2. D: Double-acting (air pressure drives both opening and closing actions)
2. S: Single-acting (spring return; automatic reset upon air supply loss for safety protection)
2. Stainless Steel Piston Version: Pistons, drive gears, and fasteners are all made of stainless steel for enhanced corrosion resistance.
III. Key Structural Features
2. All-Stainless-Steel Piston Corrosion-Resistant Structure: Pistons, racks, gears, and fastening screws are all constructed from stainless steel. This eliminates issues such as rusting, jamming, corrosion, and material degradation, making it suitable for humid, salt-spray, and mildly acidic or alkaline environments, while offering durability far superior to standard aluminum pistons.

1. Symmetrical Dual-Piston Rack-and-Pinion Drive: Delivers symmetrical force in both directions, resulting in uniform torque output, smooth opening and closing, no impact or vibration, and high repeatability in positioning. • Precision-adjustable mechanical stops: Mechanical limit adjustments at both ends with ±5° fine-tuning ensure precise sealing at full-open and full-closed positions, eliminating issues such as incomplete closing or opening.

• High-strength anodized cylinder body: Constructed from high-quality aluminum alloy with a hard-anodized finish, the cylinder is wear-, scratch-, and aging-resistant; the low-friction inner wall ensures smooth, effortless operation.
• High-quality sealing components: Utilizes imported seals resistant to extreme temperatures and aging, ensuring excellent airtightness, zero leakage, and a long service life—even with frequent, long-term cycling.
• Standard universal interfaces: The output shaft, mounting flange, and air connections fully comply with ISO5211, NAMUR, and DIN3337 standards, offering excellent versatility and interchangeability.
• Safe, explosion-proof, and maintenance-free: Features a purely pneumatic design with no electrical sparks, ensuring intrinsic safety and explosion protection; requires no routine lubrication and boasts an extremely low failure rate. IV. Material Specifications

1. Cylinder Body: Extruded aluminum alloy, hard-anodized finish

• Piston, Rack, Pinion: All stainless steel (corrosion-resistant upgrade)
• Output Shaft: High-strength stainless steel, forged as a single piece

2. Fasteners: All stainless steel
3. Seals: NBR, HNBR, FKM (Fluoroelastomer) (options available for high/low temperatures)
4. Springs: High-toughness precision springs (for single-acting models)
   V. Technical Parameters

• Operating Air Supply: 0.4–0.8 MPa clean, dry compressed air
• Output Angle: 0°–90° (adjustable ±5°)

2. Actuation Type: Double-acting (AT-D) / Single-acting (AT-S) spring return
3. Operating Temperature: -20°C to +80°C (customizable seals available for -40°C to +120°C)
4. Protection Rating: IP65
5. Output Torque: Full range coverage from 3 Nm to 10,000 Nm
6. Mounting Standards: ISO5211, NAMUR, DIN3337
7. Control Method: On/Off control / 4–20mA proportional control
8. Accessories: Solenoid valves, air preparation units (FRL), limit switches, valve position feedback, smart positioners, emergency handwheels
   VI. Suitable Operating Conditions
   ✅ Scenarios suited for stainless steel pistons
9. Coastal environments: Salty sea air/mist, high humidity, rust-prone conditions
10. Valves for corrosive pipelines in sewage treatment, chemical wastewater, and desulfurization/denitrification systems
11. Clean, corrosion-resistant workshops in pharmaceutical, food, and fine chemical industries
12. Long-term outdoor exposure, wet/rainy conditions, and unmanned operation
13. Automation systems requiring high durability, low failure rates, and prevention of rust-induced valve jamming
    ❌ Unsuitable Operating Conditions
14. Direct immersion of the actuator body in highly corrosive liquid media
15. Operating conditions involving extreme temperatures (ultra-high or ultra-low) exceeding rated limits
    VII. Standards

• Design and manufacturing: ISO 5211, DIN 3337, NAMUR standards
• Protection rating: IP65

2. Explosion-proof rating: Ex d IIC T6 (explosion-proof configuration optional)
   VIII. Installation and Operating Instructions
3. Before installation, verify that the valve’s open/closed status aligns with the actuator’s rotation direction and ensure the torque specification matches the valve load.

• The air supply must be clean and dry; install a filter-regulator upstream. Air supplies containing water, oil, or impurities are prohibited.

2. Before supplying air, manually adjust the limit screws at both ends to allow for fine-tuning clearance, then slowly supply air to test the full-stroke operation.

• Double-acting models: Alternating air supply to the two ports controls opening and closing; single-acting models feature automatic spring return upon loss of air pressure, ensuring process safety.
• For outdoor or corrosive environments, the stainless steel piston model is recommended to eliminate rust and jamming issues common with standard aluminum pistons.
• Regularly check air supply cleanliness and seal integrity; during prolonged shutdowns, perform no-load cycling maintenance once a month.
  IX. Summary of Product Advantages
  The AT stainless steel piston pneumatic actuator features upgraded, fully stainless steel transmission components, thoroughly resolving common issues found in standard actuators such as rusting, jamming, air leakage, and short service life. Its rack-and-pinion transmission delivers high torque, stable operation, high precision, and broad compatibility. With IP65 protection and intrinsic safety/explosion-proof capabilities, it is the optimal actuation solution for pneumatic automated valves in harsh environments involving high humidity, salt spray, corrosion, or outdoor exposure.