Explosion-Proof Actuators: Applications in Hazardous Areas

1. What Is an Explosion-Proof Actuator?

An explosion-proof actuator is a device designed to operate in hazardous environments without igniting flammable substances in the surrounding atmosphere.

The Principle of Explosion-Proof Enclosure:

Contrary to what the name might suggest, explosion-proof actuators are not designed to prevent explosions inside the housing. Instead, they are engineered to:

1. Contain the explosion: If flammable gases enter the enclosure and ignite, the housing is strong enough to withstand the pressure without rupturing.

2. Cool escaping gases: Any flames or hot gases that escape must pass through specially designed flame paths (tightly controlled gaps) that cool them below the ignition temperature of the external atmosphere.

Result: An internal explosion is contained and safely extinguished before it can ignite the surrounding hazardous area.

2. Hazardous Area Classifications

To select the right explosion-proof actuator, you must understand the hazard classification of your facility.

International System (IECEx / ATEX)

Gas Groups:

• Group I: Mining (methane)

• Group IIA: Propane (typical industrial gases)

• Group IIB: Ethylene (chemical plants)

• Group IIC: Hydrogen, Acetylene (most explosive)

Temperature Classes (T-Ratings):

The actuator's surface temperature must never exceed the ignition temperature of the surrounding gases.

North American System (NEC / CEC)

3. Why Pneumatic Actuators Are Preferred for Hazardous Areas

Electric actuators contain components (motors, switches, circuit boards) that can spark during normal operation. Making them explosion-proof requires heavy, expensive enclosures and specialized design.

Pneumatic actuators, like the KINKO JAT-SR Series, offer a simpler solution:

Advantages of Pneumatic Actuators in Hazardous Areas:

The KINKO JAT-SR Advantage:

• ATEX-certified models available for Zone 1 and Zone 2 applications.

• Optional stainless steel construction for corrosive hazardous environments.

• Conductive coatings to prevent static buildup.

• Spring return models provide fail-safe operation without electrical power.

4. KINKO JAT-SR Series for Hazardous Areas

The JAT-SR Series pneumatic actuators are ideal for explosion-proof applications when properly specified with the right options.

Standard Features Relevant to Hazardous Areas:

ATEX Certification Options:

KINKO offers JAT-SR variants certified for use in:

• II 2G Ex h IIC T6 Gb (Gas, Zone 1)

• II 2D Ex h IIIC T85°C Db (Dust, Zone 21)

• Temperature Class T6 (85°C max surface temperature)

5. Applications Across Hazardous Industries

A. Oil & Gas Upstream (Wellheads, Platforms)

Applications:

• Emergency shutdown valves (ESD)

• Wing and master valves on Christmas trees

• Flow control manifolds

• Separator inlet/outlet valves

Why KINKO JAT-SR:

• Spring return models provide fail-safe closure on air loss.

• ATEX Zone 1 certification for wellhead areas.

• Corrosion-resistant options for offshore environments.

B. Refineries and Petrochemical Plants

Applications:

• Burner management systems

• Isolation valves on process units

• Loading arms and truck racks

• Flare gas recovery systems

Why KINKO JAT-SR:

• Fast stroking speeds for emergency isolation.

• SIL 3 capable for safety instrumented systems.

• Wide temperature ranges for process heat.

C. Chemical Processing

Applications:

• Reactor feed isolation

• Solvent transfer systems

• Hazardous material storage

• Batch processing with flammable chemicals

Why KINKO JAT-SR:

• Non-sparking materials prevent ignition.

• Compatible with corrosive atmospheres.

• Simple maintenance reduces exposure risk.

D. Pharmaceutical Manufacturing

Applications:

• Solvent handling systems

• Reactor isolation

• Clean-in-place (CIP) systems with flammable cleaning agents

Why KINKO JAT-SR:

• Clean design with minimal crevices.

• Options for cleanroom compatibility.

• Reliable operation in classified pharmaceutical areas.

E. Mining and Mineral Processing

Applications:

• Coal handling (dust explosion risk)

• Slurry valves in processing

• Ventilation controls

• Dewatering systems

Why KINKO JAT-SR:

• Dust ignition protection (ATEX for dust).

• Robust construction for harsh mining environments.

• High torque for large valves.

F. Paint and Coating Facilities

Applications:

• Solvent delivery systems

• Mixing vessel isolation

• Ventilation dampers

Why KINKO JAT-SR:

• Conductive options prevent static discharge.

• Reliable operation with frequent cycling.

• Compact design for tight spaces.

G. Grain Handling and Food Processing

Applications:

• Dust collection systems

• Grain transfer valves

• Bin isolation gates

Why KINKO JAT-SR:

• Dust ignition protection.

• Food-grade lubricants available.

• Washdown-capable options.

6. Electric Options for Hazardous Areas

While pneumatic is preferred, some applications require electric actuation. KINKO offers KK Series electric actuators with explosion-proof enclosures for specific needs.

When to Choose Explosion-Proof Electric (KK Series Ex):

• No compressed air available on site.

• Precise modulating control required.

• Remote monitoring and IIoT connectivity essential.

• Battery backup fail-safe needed.

KK Series Ex Features:

• Flameproof enclosure (Ex d) certified.

• ATEX/IECEx for Zone 1 and Zone 2.

• IP66/IP68 protection.

• Integrated position feedback.

• Modbus and PROFINET communication.

7. Selection Guide: Choosing the Right Explosion-Proof Actuator

8. Critical Considerations for Explosion-Proof Installations

A. Entire System Must Be Certified

The actuator alone is not enough. All components in the hazardous area must be suitably rated:

• Solenoid valves (must be ATEX-rated for the zone)

• Limit switch boxes (must be explosion-proof)

• Positioners (must be certified)

• Cabling and conduits (must meet installation standards)

B. Installation Matters

Even certified equipment can become unsafe if improperly installed:

• Conduit seals must be installed correctly.

• Cable glands must be appropriate for the zone.

• Grounding and bonding must be verified.

C. Regular Inspection

Explosion-proof equipment requires periodic inspection to ensure:

• Flame paths are not damaged or corroded.

• Gaskets and seals are intact.

• No unauthorized modifications have been made.

9. KINKO Explosion-Proof Product Comparison

Conclusion

Explosion-proof actuators are not optional in hazardous areas—they are a critical safety requirement. Whether you are automating valves on an offshore platform, a chemical reactor, or a grain handling facility, choosing the right certified actuator protects both your personnel and your facility.

KINKO offers comprehensive solutions for hazardous area actuation:

• JAT-SR Series Pneumatic Actuators: The preferred choice for most hazardous areas—simple, reliable, ATEX-certified, with fail-safe spring return options.

• KK Series Ex Electric Actuators: For applications requiring precise control or where compressed air is unavailable.

Have a hazardous area application?
Contact KINKO today with your zone classification, gas group, and valve details. Our engineers will recommend the right certified solution for your safety requirements.

Ivan (Mobile:+86-18968769287)
          WhatsApp：+86-13579991606

Wechat:+86-18968769287

Website：www.kinko-flow.com
ZHEJIANG KINKO FLUID EQUIPMENT CO.,LTD