Fireproof partitions are installed on fire cable trays

Fireproof partitions (fire-blocking sections) are essential for isolating cable tray sections, preventing fire spread, and ensuring safe operation in industrial and power facilities.

Purpose and Importance

Fireproof partitions, also known as fire-blocking sections, are installed along cable trays to prevent the propagation of fire, protect critical equipment, and reduce casualties and property damage in case of fire incidents. They are particularly important in high-risk environments such as power plants, substations, industrial facilities, and high-rise buildings, where aging equipment or external fire sources can trigger fires .

Materials and Types

Common materials used for fireproof partitions include:

• Fireproof boards: Provide strong fire resistance but are heavy and occupy space, which may affect cable maintenance .
• Fireproof coatings and paints: Easy to apply, offer good heat dissipation, and are convenient for adding or replacing cables .
• Fireproof bags and mud: High strength and durable, but may have variable fire resistance and complex installation .
• Intumescent caulks and moldable putty: Products like 3M Fire Barrier Moldable Putty+ or IC 15WB Caulk expand under heat to seal openings, block heat penetration, and are suitable for retrofitting or new installations . Each material has trade-offs in terms of installation complexity, durability, fire resistance, and maintenance requirements.

Installation Guidelines

• Partition dimensions: The width of the fireproof partition should be at least equal to the width of the cable tray to effectively block fire spread .
• Slab penetrations: Provide 20–30 mm of firestopping at floor or slab penetrations, with waterstops of at least 50 mm in height .
• Tray openings: Use UL-listed firestop systems for openings, ensuring proper sealing around trays with pillows, putty, or caulk as specified by manufacturers .
• Segregation: Power and signal cables should be separated to reduce fire risk and electromagnetic interference .
• Periodic inspection: Fireproof partitions and coatings require regular inspection to ensure integrity, especially in outdoor or corrosive environments .

Standards and Ratings

Fireproof partitions should comply with national and international fire safety standards, including UL ratings for fire resistance. Typical ratings include:

• Concrete walls: 3-hour F-rating, 3/4-hour T-rating
• Gypsum walls: 1–2-hour F-rating, 0–1/2-hour T-rating The firestop system's hourly rating should match or exceed the wall assembly's rating to ensure effective fire containment.

Practical Considerations

• Choose materials based on environmental conditions, such as exposure to moisture, UV, chemicals, or rodents .
• Consider ease of maintenance and the ability to add or replace cables without compromising fire protection.
• For high-density or critical installations, intumescent coatings or moldable putty offer a balance of fire resistance, flexibility, and long-term performance . By selecting appropriate materials and following proper installation practices, fireproof partitions can significantly enhance the safety and reliability of cable tray systems in industrial and commercial facilities.