Heater Burner Ex Rating Requirements.

[S.G]

Hello All,

Would you agree with the below:

In an oil and gas plant, the decision to use an explosion-proof (Ex) rated dual-fuel burner (for gas and diesel) depends on the classification of the hazardous area where the burner will be located. The Ex rating is often required for equipment in potentially explosive atmospheres to prevent ignition of flammable gases or vapors.

Standards and Guidance​

1. Hazardous Area Classification:
   • For oil and gas facilities, refer to IEC 60079-10-1 ("Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas atmospheres") or NFPA 497 ("Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas").
   • These standards provide guidance on determining whether the area where the burner will be located is classified as a hazardous zone (Zone 0, Zone 1, or Zone 2) due to the presence of flammable gases or vapors.
2. Burner Equipment Certification:
   • If the area is classified as a hazardous zone, IEC 60079-1 ("Explosive atmospheres – Part 1: Equipment protection by flameproof enclosures 'd'") and IEC 60079-2 ("Explosive atmospheres – Part 2: Equipment protection by pressurized enclosures 'p'") provide the requirements for equipment certification.
   • API 556 ("Instrumentation, Control, and Protective Systems for Gas Fired Heaters") and NFPA 86 ("Standard for Ovens and Furnaces") also include guidance on dual-fuel burner safety, focusing on proper controls, monitoring, and interlocks to prevent ignition risks.
3. Safety and Design:
   • Ensure the burner’s design has suitable flame arrestors, gas detectors, and safety interlocks to control fuel switching between gas and diesel and to manage potential leaks.
   • The burner must also meet ATEX or IECEx certification requirements if located in a hazardous zone, indicating it is suitable for explosive atmospheres.

Given that gas and diesel fuel could create a hazardous area under certain conditions, an Ex-rated burner may be necessary if the area is classified as hazardous by IEC 60079-10-1 or NFPA 497 standards.