Markings

In hazardous locations, all three certification schemes have different markings as following.

1. North American Markings

North American certification focuses on Class, Division, and Group classifications. Equipment must be tested and approved by recognized certification bodies such as UL (Underwriters Laboratories), FM (Factory Mutual), or CSA (Canadian Standards Association).

Marking Example:

• Class I, Division 1, Group B, C, D

  • Class I: Equipment is suitable for locations with flammable gases or vapors.

  • Division 1: Hazardous conditions are present under normal operating conditions.

  • Group B, C, D: Specifies the type of gases or vapors for which the equipment is suitable. For example, Group B covers hydrogen and acetylene, while Groups C and D cover other flammable gases and vapors.

Sample Marking:

• "Class I, Division 1, Group B, C, D; T4"

  • Indicates that the equipment is suitable for use in Class I locations, Division 1, and Groups B, C, and D gases, with a temperature rating of T4 (135°C).

2. ATEX Markings

ATEX (ATmosphères EXplosibles) certification is used in the European Union and involves two main directives: Directive 2014/34/EU (for equipment) and Directive 99/92/EC (for workplace safety). Equipment is categorized into different categories based on the level of protection required.

Marking Example:

• II 2G Ex d IIB T4

  • II: Equipment intended for use in non-mining industries.

  • 2G: Equipment suitable for use in Zone 1 (gases) environments.

  • Ex d: Flameproof protection.

  • IIB: Equipment suitable for gases classified as Group IIB (e.g., ethylene).

  • T4: Temperature classification, with T4 indicating a maximum surface temperature of 135°C.

Sample Marking:

• "II 2G Ex d IIB T4 Gb"

  • Gb: Equipment suitable for Zone 1, offering a higher level of protection compared to Category 2G.

3. IECEx Markings

IECEx (International Electrotechnical Commission System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres) provides a globally recognized certification system. It follows the IEC 60079 series of standards and uses Zones for classification.

Marking Example:

• Ex d IIB T4 Gb

  • Ex d: Flameproof protection.

  • IIB: Equipment suitable for gases classified as Group IIB.

  • T4: Temperature classification, with T4 indicating a maximum surface temperature of 135°C.

  • Gb: Equipment suitable for Zone 1 environments.

Sample Marking:

• "Ex d IIB T4 Gb"

  • The marking indicates that the equipment is certified for use in Zone 1 environments, with a flameproof protection concept, suitable for gases in Group IIB, and a temperature classification of T4.

Comparison of Markings

• North American Markings: Focus on Class, Division, and Group. The marking indicates the type of hazardous environment and the type of hazardous materials. It often includes temperature classifications (e.g., T4).

  • Example: "Class I, Division 1, Group C, T4"

• ATEX Markings: Use a combination of category, protection type, and temperature class. The marking includes the equipment category and zone suitability, with specific protection methods (e.g., Ex d for flameproof).

  • Example: "II 2G Ex d IIB T4"

• IECEx Markings: Employ a similar system to ATEX but with international standardization. The marking includes the Ex code for protection concepts and zone classifications.

  • Example: "Ex d IIB T4 Gb"

Conclusion

Understanding the differences between North American, ATEX, and IECEx markings is crucial for ensuring compliance and safety in hazardous environments. Each system provides a unique way of classifying and marking equipment, tailored to regional standards and regulations. By familiarizing yourself with these marking systems and their implications, you can ensure that equipment meets the necessary safety requirements and is suitable for its intended application.