In industrial environments such as refineries, chemical plants, or gas processing facilities, flammable gases, vapors, or dusts can create hazardous locations, areas where a single spark or overheated surface could ignite an explosion. Explosion-proof (or “hazardous location rated”) heat trace products are engineered to operate safely in these environments by containing any potential ignition source within sealed, certified components.
For electrical heat tracing systems, this means that all power connections, splices, and terminations must be designed to prevent the ignition of surrounding flammable atmospheres. These ratings are defined under the National Electrical Code (NEC) and Canadian Electrical Code (CEC) using a system of Class and Division designations.
Understanding Class and Division Ratings
- Class I– Areas where flammable gases or vapors are present in the air in quantities sufficient to produce explosive or ignitable mixtures.
- Division 1 (continuously hazardous) – Hazardous gases or vapors are present under normal operating conditions (e.g., inside process units, pump skids, or enclosed pipe racks).
- Division 2 (occasionally hazardous) – Hazardous gases or vapors are only present under abnormal conditions, such as a leak or equipment failure.
Electrical engineers and installers must design systems so that each component used in these areas carries the appropriate certification for its environment. Improper ratings can result in unsafe installations or code violations.
Drexan Explosion-Proof Heat Trace Solutions
Drexan’s PipeGuard self-regulating heat trace cables are rated for Class I, Division 1 applications. They are engineered and certified for continuous operation in the most hazardous gas environments.
All system components, including Drexan’s heat shrink family of connection kits, are rated for Class I, Division 2 locations. However, metallic connection components (such as junction boxes, fittings, and glands) can also be used in Class I, Division 1 environments when installed with Drexan’s DIV1-ADP (DREX0019) Class I, Div 1 Adapter Kit for each cable entry.
This adapter kit ensures that the mechanical and electrical interfaces maintain explosion-proof integrity and meet certification standards for Div 1 zones.
Installation Considerations
In many industrial installations, electrical designers and installers will locate connection points or junction boxes at least 3 meters (10 feet) outside the Division 1 hazardous area. This effectively reclassifies those components to a Division 2 zone, allowing the use of less costly Div 2-rated accessories while maintaining full compliance and safety.
Proper classification, component selection, and installation practices help ensure:
- Regulatory compliance (CSA, UL, or FM-certified for hazardous locations)
- Worker and facility safety
- System reliability even in explosive atmospheres
Summary for Engineers and Installers
| Component | Rating | Notes |
| PipeGuard Cable – PipeGuard Hot, PipeGuard Warm | Class I, Div 1 | Safe for continuous use in explosive gas environments |
| Heat Shrink Family | Class I, Div 2 | Safe for normally non-hazardous operation or Div 2 zones |
| Metallic Components (with DIV1-ADP kit) | Class I, Div 1 | Must use DIV1 adapter kit for each cable entry |
| Connection relocation (3 m outside Div 1) | — | Allows reclassification to Div 2 zone for safer, simpler installation |
For more information, read our Zone Information Guide.