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Special ATEX Flanged Immersion Heaters


Designed for hazardous areas, special ATEX-compliant flanged immersion heaters provide superior safety, efficiency, and long-term reliability for heating liquids, air, and gases.Rely on an highly secure cloud storage.

ATEX EX


ATEX Industrial Fluid Circulation Heaters

Caldor Heat designs and manufactures ATEX-certified industrial fluid circulation heaters engineered to meet precise heating requirements for water, fuel oil, and thermal oil across a wide range of industrial applications.

Our industrial fluid heaters are developed to deliver maximum thermal efficiency, stable heat transfer, and accurate temperature control, ensuring reliable performance even in the most demanding operating conditions.

We offer multiple fluid circulation heater models, each custom-engineered according to the customer’s technical specifications, process requirements, and site conditions. As a result, every heater we produce is fully customized, application-specific, and optimized for long-term operation.

Safety is a core design principle. Our heaters can be equipped with advanced explosion-proof protection systems and are fully compliant with ATEX directives, making them ideal for use in hazardous and potentially explosive environments.

If you are looking for a reliable, custom ATEX heating solution, our engineering team is ready to support your project.

Contact us today to discuss your specific application requirements.

Technical Information

Caldor Heat Engineering designs and manufactures ATEX-compliant flanged immersion heaters for the safe and efficient heating of liquids and gases in hazardous areas.

Our immersion heaters are suitable for use in ATEX Zones 1, 2, 21, and 22, covering both gas and dust explosive atmospheres. Required conformity and documentation can be provided upon request.

Design and Protection Concept

ATEX flanged immersion heaters are engineered using flameproof enclosure (Ex d) and increased safety (Ex e) concepts, combined with ingress protection up to IP66.

Each heater can be supplied with the appropriate temperature class compliance, selected according to process conditions, installation environment, and customer specifications.

Suitable protection, monitoring, and control systems ensure accurate temperature regulation and protection against overheating.

Terminal Enclosure

The terminal enclosure is designed according to Ex e (increased safety) principles, providing secure electrical connections and ease of maintenance in hazardous locations.

Materials
Heating Element Sheath
  • Stainless steel (321, 316Ti, 316L)
  • Nickel-based alloys
  • Other materials upon request
Flange Connection
  • Carbon steel
  • Stainless steel
  • Customer-specified materials
Connection Enclosure (Ex)
  • Carbon steel or cast construction with protective coating
  • Stainless steel for corrosive or offshore environments
Pressure-Rated Design

Pressure-rated immersion heaters can be designed and manufactured in accordance with applicable pressure equipment standards, based on customer-defined requirements. Final design parameters are determined during the engineering phase.

Specific Surface Load

The specific surface load defines the heat transfer rate to the heated medium and is selected based on fluid properties, flow rate and pressure, installation conditions, and maximum allowable surface temperature.

Typical Surface Load Ranges
  • Heavy oils, gear oils, bitumen: 0.8 – 1.0 W/cm²
  • Hydraulic oil, thermal oil: 1.5 – 2.3 W/cm²
  • Water / glycol mixtures: 2 – 4 W/cm²
  • Circulating gases: 0.5 – 3 W/cm²
  • Anti-condensation heating: 0.25 – 0.4 W/cm²
Immersion Heater Types
DHF Type – Liquid Heating

Designed for heating lubrication oil, fuel oil, and process fluids. A level control system is required to ensure continuous liquid coverage of the heating elements.

DHG Type – Gas and Air Heating

Designed for air or gas heating under stagnant or circulating conditions. Temperature class compliance is selected according to operating conditions and ATEX zone requirements.

Additional Components

Explosion-Proof Level Switch – Horizontal or vertical mounting options for safe level monitoring.

Thermal Limiter – Reliable monitoring of heater surface temperature and integration into safety systems.

Power and Temperature Control – Customized control solutions from on/off panels to advanced power regulation.

Applications and Industries 


Typical Applications for ATEX Flanged Immersion Heaters – Gas or Air

  • Motor anti-condensation heating

  • Heating of hot boxes and instrumentation cabinets

  • Heating elements for gas heater systems

    (Depending on the application, a flow monitoring device may be required to prevent overheating)

  • Lubrication oil heating systems
  • Thermal oil heating applications
  • Tanks containing water or process fluids
  • Heat exchangers

Quality and Excellence

With extensive experience and deep industry knowledge, we provide insights and solutions that keep you ahead of the curve.

Industries Served

ATEX-compliant flanged immersion heaters are widely used across a broad range of industrial sectors, including:

  • Petrochemical, chemical, and pharmaceutical industries

  • Oil and gas extraction, production, and distribution

  • Mechanical engineering and industrial plant construction

  • Paint, coating, and surface treatment industries

  • Energy generation and environmental technologies

  • Laboratory, testing, and analytical applications

  • Plastics processing and textile manufacturing

  • Packaging and material handling

  • Industrial gas processing and distribution