In a major fire, 90% of casualties are not from burns, but from smoke inhalation. Even more terrifying, modern high-rise buildings are like chimneys. During a fire, flames and toxic smoke can spread vertically at a speed of 3-5 meters per second through cable holes in walls and floors, as well as gaps in pipes. In just three minutes, they can reach from the first to the 30th floor!

Traditional methods of sealing holes with fireproofing putty and fireproofing bags are time-consuming, labor-intensive, and ineffective. Now, a new, powerful tool, like Lego bricks, is emerging, offering fireproofing performance comparable to the Great Wall of Steel. The TST SEAL wedge-shaped fireproof sealing module is quietly changing the landscape of fire protection in high-rise buildings, subways, and nuclear power plants.

What is it? An “expanding fireproof brick”
Imagine: a cable passes through a firewall, leaving an irregular hole. Previously, workers had to manually insert fireproofing putty, bit by bit. This was laborious and could cause cracking and falling off over time. The TST SEAL wedge-shaped fireproof sealing module is a wedge-shaped block made of flexible fire-resistant materials (such as ceramic fiber and expanded graphite). During installation, it’s hammered into the hole like a wedge. The further it goes, the tighter it expands, automatically adapting to gaps of all sizes and shapes.

But its most impressive feature is its “superpower”—expansion when exposed to fire!

When the temperature reaches 200°C, the intumescent material inside the module instantly activates, expanding 5-10 times its volume, completely sealing all gaps like a rising dough bun. Even after a fire lasts for 120 minutes (reaching its 3-hour fire resistance limit), it forms a solid carbonized layer, insulating against flames and high temperatures.

Real battlefields: These are where it becomes a “life-saving module.”

Super-high-rise residential buildings: Blocking the “chimney effect”

In a 500-meter landmark residential building in Shenzhen, numerous cables and pipes run through every floor. The developer used TST SEAL prefabricated wedge-shaped sealing modules, which were pre-installed in the floor casing at the factory. This required only one final touch on-site, increasing installation efficiency fivefold.

Result: During fire inspection, the back-of-fire surface temperature remained below 180°C during simulated fire tests, fully meeting the requirements of GB50016, the “Code for Fire Protection Design of Buildings.”

Subway Tunnels: Making Escape Routes Truly “Safe”
Subway tunnels are densely populated with cables, and traditional fireproofing can easily loosen under vibration. A new Beijing Metro line uses seismic-resistant wedge-shaped modules, whose unique snap-fit ​​structure can withstand earthquake vibrations of magnitude 8.

Case Study: During a fire drill in a section, sealing modules near the fire point rapidly expanded, successfully preventing the fire from spreading to adjacent sections and buying passengers valuable escape time.

Nuclear Power Plants: The “Last Line of Defense” for Nuclear-Grade Safety
Nuclear power plants have extremely stringent fire protection requirements. A nuclear power project employed nuclear-grade wedge-shaped sealing modules that meet RCC-E standards when cables pass through fire compartments. Not only does it withstand three hours of fire, it also resists radiation, moisture, and chemical corrosion, ensuring continuous power supply to safety systems in the event of an accident.

Industry Trends: From “Manual Hole Plugging” to “Smart Fire Prevention”

Modularization and Prefabrication Become the Mainstream

The traditional “on-site construction” model is becoming obsolete. The current trend is to prefabricate wall bushings with sealing modules in the factory and install them directly on-site. This offers controlled quality and a fast schedule, perfectly aligning with the trend of prefabricated buildings.

Multifunctional Integration: Fireproof + Waterproof + Explosion-Proof + Small Animal Repellent
High-end wedge-shaped modules are no longer just “single-function players.”

Waterproof: Suitable for underground garages and civil air defense projects, with IP68 waterproofing.

Explosion-Proof: Suitable for petrochemical plants, capable of withstanding explosion shock waves.

Rodent-Proof: Built-in metal mesh prevents small animals from gnawing and causing short circuits.

Green and Sustainable: TST SEAL’s new generation modules are made of halogen-free, low-smoke, and non-toxic materials. They do not release corrosive gases during combustion, reducing secondary harm to personnel and equipment and meeting LEED green building standards.

Why is it so popular? Three Core Advantages

Fast: Installation speed is 3-5 times faster than traditional methods, allowing one worker to drill a hole in 10 seconds, significantly shortening construction time.

Secure: Mechanical wedge tightening plus fire expansion provide dual protection, ensuring earthquake resistance and durability, with a 10-year lifespan.

Economical: While the unit price is slightly higher, this solution reduces labor and repairs, resulting in lower lifecycle costs.

Selection Tips: Don’t be fooled by “fake expansion” claims.

Some “pseudo-wedge” modules on the market:

Poor-quality materials: Using ordinary foam instead of expanded graphite, which can burn through directly in fire.

Falsely labeled expansion ratio: Claimed expansion ratio is 10 times, but measured expansion ratio is less than 3 times.

Uncertified: Failed to pass fire tests such as UL1479 and GB 23864.

The Right Approach: Verify the third-party test report, review key data such as fire resistance time, temperature rise on the back-fired side, and expansion ratio, and choose a reputable brand (such as TST SEAL or TST CABLE).

In an era where life is paramount, fire prevention is no longer a post-event fix, but a proactive approach. The TST SEAL wedge-shaped fireproof sealing module, though as small as a brick, is a critical link in a building’s fire protection system.

It utilizes the simplest mechanical principles to achieve the most reliable passive fire protection. From skyscrapers to underground utility tunnels, from hospitals and schools to nuclear power equipment, this “expanding fireproof brick” silently protects the lives of hundreds of millions of people. In the future, with the development of smart buildings and resilient cities, the role of this “invisible hero” will only grow in importance.