Pneumatic Rack And Pinion Actuator For Valve Automation

Pneumatic Rack and Pinion Actuator for Valve Automation

OVERVIEW

This rack-and-pinion pneumatic actuator features a high-strength aluminum alloy cylinder body with a hard-anodized surface finish, offering a compact structure, lightweight design, and stable output torque. It is widely used to actuate ball valves, butterfly valves, and other quarter-turn valves, utilizing compressed air to achieve 90° on/off switching or modulating control.

Available in both double-acting (DA) and spring-return (SR) configurations, the unit includes external travel adjustment screws for precise fine-tuning of the switching position within the 0–90° range. Standard NAMUR air supply interfaces and ISO 5211 bottom mounting flanges facilitate the installation of solenoid valves and limit switches, as well as direct connection to valves. With reliable sealing and a long service life, it is suitable for applications in petrochemicals, water treatment, energy, metallurgy, and general industrial automation systems.

FEATURES OF ELECTRIC ACTUATORS

•Extruded aluminum (ASTM 6005) cylinder body with a precision-honed internal surface; both internal and external surfaces feature advanced anti-corrosion treatment, ensuring low friction, a long service life, and superior corrosion resistance.

•Dual-piston rack-and-pinion design featuring a compact structure, symmetrical mounting, easy output shaft rotation reversal, long service life, and rapid operation.

•Modular pre-loaded coated springs designed for a long service life.

•Composite bearings and guide rings fitted to the back of the piston racks ensure precise movement, low friction, and extended service life.

•High-precision gears and racks with minimal backlash and high accuracy, delivering high output torque.

•Stainless steel fasteners offer safety, an attractive appearance, and strong corrosion resistance.

•Compliant with international dimensional standards: output shaft slots and screw holes; top mounting holes meet NAMUR standards; air supply ports meet NAMUR standards; and bottom mounting holes comply with ISO 5211 and DIN 3337 standards, facilitating the installation of accessories such as solenoid valves and limit switches.

MAIN FUNCTIONS

Explosion Proof

Based on your specific hazardous area classification and medium type (Group IIA/IIB/IIC gases or dusts), custom-engineer explosion-proof mini‑type electric flanged ball valve consists of an electric actuatorthat fully comply with international and domestic standards, including IECEx, ATEX, and GB 3836.

Colors

You can provide your own color code or choose special coatings for corrosion resistance, weather resistance, or high-temperature warning. Using advanced spraying technology and high-quality coatings, we ensure a durable, uniform finish. This gives your equipment a personalized look while maintaining long-term durability in industrial environments.

Protection grade

Based on your installation environment - outdoor rain, coastal salt spray, desert dust, or food/pharma workshops needing high-pressure washing. We provide sealing solutions from basic dust/water protection (IP65/IP67) to ultra-high protection (IP68/IP69K).

Low-temperature

For the specific operating conditions in extremely cold regions, we offer professional, deeply customized low-temperature environment services for Manual Worm‑gear PTFE‑Lined Butterfly Valve . By employing special low-temperature resistant materials, wide-temperature-range lubricants, and intelligent heat tracing systems, we ensure that the equipment can reliably start and operate accurately even in extremely low-temperature environments. We also comprehensively optimize the cold resistance of seals, electronic components, and display screens to effectively prevent problems such as lubrication freezing, sluggish displays, or start-up failures caused by low temperatures.

Parts and Materials

Double-acting actuator

When air enters through port A, compressed air drives the pistons outward, causing the actuator output shaft to rotate counter-clockwise (0° to 90°), while air exhausts through port B.

When air enters through port B, compressed air drives the pistons inward, causing the actuator output shaft to rotate clockwise (90° to 0°), while air exhausts through port A.

When air enters through Port A, compressed air drives the pistons outward, causing the actuator output shaft to rotate clockwise (0–90°), while air exhausts through Port B.

When air enters through Port B, compressed air drives the pistons inward, causing the actuator output shaft to rotate counter-clockwise (90–0°), while air exhausts through Port A.

Output Torque of FRYG Series Double-Acting Pneumatic Actuators (Unit: N·m)

Single-acting actuator

Output Torque of FRYG Series Single-Acting Pneumatic Actuators (Unit: N·m)

Selection of Single-Acting Actuators

Under normal operating conditions, a safety factor of 30%–50% is applied to single-acting actuators.

Example:

Required valve torque = 80 N·m

Safety torque = 80 × (1 + 30%) = 104 N·m

Air supply pressure = 5 bar

Consulting the output torque table for single-acting actuators, we find the following for the SR140K7:

Air stroke 0° = 308 N·m

Air stroke 90° = 247 N·m

Spring stroke 90° = 180 N·m

Spring stroke 0° = 120 N·m

All output torque values ​​exceed the requirements.

Note:

During the spring return process of a single-acting actuator, supplying air to Port B does not affect the actuator's output torque; instead, it assists the spring return actio

Spring mounting configuration for single-acting actuators

Technical conditions for operation

1. Operating media: Compressed air, non-corrosive gases, and oil;

2. Pressure range: Double-acting 2–8 bar; Single-acting 2–8 bar;

3. Operating temperature: -20°C to +80°C (Standard type, using NBR O-rings); -40°C to +80°C (Low-temperature type, using silicone rubber O-rings); -20°C to +150°C (High-temperature type, using FKM O-rings);

4. Travel adjustment: ±4° adjustment range at the 90° position;

5. Lubrication: No additional lubrication required under normal operating conditions;

6. Installation: Suitable for indoor or outdoor installation;

7. Maximum operating pressure: Input air pressure must not exceed 8 bar.

COMPANY INTRODUCTION

Founded in 2014, Freya mainly deals in valves, actuators, electric valve actuators, electric valves and other fluid control products and services. It focuses on the process industry field and has long been committed to providing professional fluid control solutions for process industries such as electricity, steel, building materials, and water treatment. According to actual working conditions, through necessary field surveying and technical disclosure, it provides customers with safe, economical, and environmentally friendly selection and design, strictly supplies and guides installation and commissioning in accordance with contract requirements, and hands over for use when the standards are met. The company has always focused on improving its innovation capabilities, and has achieved a series of innovative results by increasing R&D investment and introducing technology. In the past few years, the company has successfully applied for non-invasive appearance patents and utility model patent certificates. These innovative achievements have improved the company's core competitiveness.

APPLICATIONS

CERTIFICATES

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