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Explosion-Proof Actuators: Applications in Hazardous Areas
Date:2026-03-19 17:52:52 Author:Zhejiang Kinko Fluid Equipment Co., Ltd

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)

ZoneDefinitionExample
Zone 0Explosive atmosphere present continuously or for long periodsInside storage tanks
Zone 1Explosive atmosphere likely to occur in normal operationPump rooms, loading areas
Zone 2Explosive atmosphere unlikely and only for short periodsAreas adjacent to Zone 1

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):

ClassMaximum Surface Temperature
T1450°C
T2300°C
T3200°C
T4135°C
T5100°C
T685°C

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

North American System (NEC / CEC)

ClassDivisionDescription
Class IDivision 1Flammable gases or vapors present under normal conditions
Class IDivision 2Flammable gases or vapors present only under abnormal conditions
Class IIDivision 1Combustible dusts present under normal conditions
Class IIDivision 2Combustible dusts present only under abnormal conditions
Class III-Ignitable fibers/flyings
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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:

FeatureBenefit
No Electrical ComponentsNo spark sources in the actuator itself
Operates on Compressed AirSafe in explosive gas and dust environments
Simple ConstructionFewer failure points than complex electric drives
Spring Return OptionsFail-safe operation without electricity
ATEX Certified MaterialsNon-sparking materials and coatings available

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:

FeatureBenefit for Hazardous Areas
Rack and Pinion DesignReliable, predictable operation
Double Acting and Spring ReturnFail-safe options without electricity
Anodized Aluminum BodyCorrosion resistant, non-sparking surface
Stainless Steel FastenersPrevent corrosion-induced sparking
Namur Mounting InterfaceDirect mount of pilot solenoids (which must be separately certified)

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.

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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

Application FactorRecommended Choice
Zone 0 (Continuous hazard)Specially certified pneumatic only (consult factory)
Zone 1 (Normal operation hazard)KINKO JAT-SR ATEX (pneumatic) or KK Series Ex (electric if required)
Zone 2 (Abnormal condition hazard)KINKO JAT-SR (pneumatic) or standard KK with care
Gas Group IIC (Hydrogen)Highest certification level required
Dust hazard (Zone 21/22)KINKO JAT-SR with dust ignition protection
Fail-safe requiredJAT-SR Spring Return (pneumatic - no power needed)
Modulating control neededKK Series Ex (electric)
No compressed air availableKK Series Ex (electric)

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

FeatureJAT-SR Series (Pneumatic)KK Series Ex (Electric)
CertificationATEX / IECEx (II 2G/2D)ATEX / IECEx Ex d
Gas GroupsIIA, IIB, IIC (depending on model)IIA, IIB, IIC
Temperature ClassT6 (85°C) availableT4 / T5 / T6 options
Zones1, 2, 21, 221, 2
Power SourceCompressed airElectric
Control TypeOn/Off (with solenoid)On/Off or Modulating
Fail-SafeBuilt-in spring returnBattery backup module
Best ForSimple on/off, high reliability, no power neededPrecise control, smart monitoring

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


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