Explosion proof pneumatic actuator are critical components in hazardous environments where flammable gases, vapors, or dust may be present. These specialized actuators prevent ignition risks by eliminating electrical sparks and using compressed air or inert gases (e.g., nitrogen) as power sources. Common applications include oil refineries, chemical plants, and mining operations.
2. Key Design Features
2.1 Explosion-Proof Certification
Complies with ATEX/IECEx standards (typically Ex d IIC T6 classification)
Utilizes flameproof enclosures to contain internal explosions
2.2 Material Selection
Aluminum or stainless steel housing for corrosion resistance
Self-lubricating bearings to minimize friction-induced sparks
2.3 Safety Mechanisms
Integrated manual override for emergency operation during power loss
SIL 2/3 compliant fail-safe systems (e.g., spring-return actuators)
3. Working Principle
Explosion-proof pneumatic actuators convert compressed air pressure into mechanical motion through:
Double-acting pistons for bidirectional control
Rotary vane mechanisms for 90° valve operation
Long pneumatic tubing to isolate control electronics from hazardous zones
4. Performance Specifications
Parameter Typical Range
Torque output 830–250,000 Nm
Operating pressure 3–7 bar
Temperature range -40°C to +120°C
Protection rating IP65/IP67
5. Industrial Applications
Oil & Gas: Pipeline valve control in Class I/II divisions
Chemical Processing: Reactor feed systems with corrosive media
Mining: Ventilation damper actuation in methane-rich environments
6. Emerging Technologies
Wireless position feedback via intrinsically safe sensors
Hybrid pneumatic-electric designs for precision throttling
7. Selection Guidelines
When specifying explosion-proof actuators, consider:
Gas group classification (IIC for hydrogen, IIB for propane)
Temperature class (T6 limits surface to 85°C)
Fail-safe requirements (spring return vs. double-acting)