Every day, millions of passengers travel between intercity rail and subway lines – they may never notice that the gaps in the carriage connections, rooftop air conditioning vents, driver’s cab wiring conduits, and substation wall penetrations are all silently protected by a precision component called the TST SEAL sealing module. It’s silent and inconspicuous, yet it’s a versatile “all-rounder” providing fire, water, smoke, vibration, and electromagnetic interference protection, truly an “invisible armor” in the rail transit safety system.

1. 1. Why do intercity rail systems have higher sealing requirements?

Compared to traditional subways, intercity rail (such as regional railways and intercity express lines) operates in a more complex environment:

Higher speeds: 160–200 km/h, leading to significant aerodynamic pressure fluctuations;

Longer lines: Frequent switching between tunnels, elevated sections, and underground sections, resulting in large temperature and humidity variations;

Fewer stops, heavier loads: Equipment operates continuously under high load, increasing the challenges of heat dissipation and vibration;

Interconnectivity: Requires compatibility with different signal systems, leading to stringent EMC (electromagnetic compatibility) requirements.

In this context, traditional sealants, foaming agents, and single rubber rings can no longer meet safety standards, making the TST SEAL modular sealing system the new industry standard.

1. 1. Core Application Scenarios and Functional Value of TST SEAL Sealing Modules

✅ 1. Carriage Connections (Gangways)

Risks: Wind noise, rainwater, and dust intrusion at high speeds; smoke spread during a fire.

Solution: EPDM peelable sealing module + stainless steel pressure frame

Effects:

IP65 protection, blocking rainwater and dust;

A-60 fire rating, preventing flame spread across carriages;

Vibration damping design reduces mechanical fatigue and extends gangway lifespan.

📌 Case Study: After adopting modular sealing, a certain intercity train in the Yangtze River Delta saw a 70% reduction in gangway failures, and passenger complaints about “leaks” dropped to zero.

✅ 2. Rooftop Equipment (HVAC, pantograph, antenna)

Risks: Rainwater infiltration leading to electrical short circuits; surge introduction from lightning strikes. Solution: Silicone sealing module + integrated grounding terminal

Effect:

IP68 waterproof, resistant to heavy rain and strong winds;

Built-in copper braided strap for equipotential connection, lightning protection;

Supports later installation of 5G antennas or monitoring sensors.

✅ 3. Underbody cable troughs and junction boxes

Risks: Impact from track ballast, oil corrosion, cable swing and wear.

Solution: High-hardness EPDM module + armored cable clamp

Effect:

Impact resistance (IK10 rating);

Clamps cables to eliminate swinging, extending service life;

Rodent-proof (meets EN 45545-2 HL3).

✅ 4. Underground substation and signal room wall penetrations

Risks: Groundwater leakage, fire spread, rodent and insect damage.

Solution: Ceramicized silicone module + A-60 stainless steel frame

Effect:

0.5MPa watertight, resistant to heavy rain backflow;

Fire resistant for 120 minutes, blocking the “chimney effect”;

Smooth surface prevents rodent pathways.

III. Technical Advantages: Why is modularization becoming mainstream?

Traditional Sealing Methods | TST SEAL Modular Sealing System

Putty/Cement: Prone to aging and cracking | EPDM/Silicone: Lifespan ≥ 30 years

Fixed aperture: Cannot be expanded | Peelable design: Supports later addition of cables

Installation relies on craftsmanship | Standardized components, ±1mm self-compensation for errors

No fire protection certification | Entire system certified by EN 45545, TB/T 3237, and multiple national classification societies

💡 Taking a 16-car intercity train as an example: After using the modular system, the sealing installation time per train was reduced from 120 hours to 40 hours, and it supports full lifecycle maintenance and upgrades.

1. 1. Key Selection Points for Rail Transit Sealing Modules

Material Matching:

Exterior of the vehicle body → UV-resistant, ozone-resistant EPDM;

Interior of electrical cabinets → Low-smoke, halogen-free silicone;

High oil contamination areas → Fluororubber (FKM). Complete Certifications:

Must meet:

EN 45545-2 (Railway Fire Protection) HL2/HL3 standards;

TB/T 3139 (Chinese Railway Standard);

RoHS/REACH environmental requirements.

Supports BIM and Digital Delivery:

Provides 3D models and installation torque parameters, compatible with intelligent manufacturing processes.

1. 1. Future Trends: Smarter, Greener, More Integrated

Intelligent Seals: Embedded strain sensors to monitor seal aging status;

Bio-based Materials: Over 30% renewable raw materials, reducing carbon footprint;

Lightweight Design: PEEK engineering plastic frame reduces weight by 40%, contributing to energy saving and consumption reduction;

Full Lifecycle Service: TST SEAL provides “Sealing-as-a-Service,” including installation, maintenance, and recycling.

On the speeding intercity train, safety is not an accident, but the inevitable result of countless details.

The TST SEAL sealing module, though small, carries the immense responsibility of fire protection, waterproofing, disaster prevention, and uninterrupted operation. It is unseen, yet omnipresent; it is silent, yet it safeguards every on-time departure and safe arrival.

As a railway engineer said: “We don’t build trains, we build trust. And trust begins with a leak-proof seal.”