Solenoid Valve Selection Guide for Rail Transit: How to Choose a Highly Reliable Solenoid Valve for Harsh Vibration and Extreme Temperature Environments

As the lifeblood of modern urban and intercity transportation, the safe, efficient, and punctual operation of rail transit is paramount. This relies on countless highly reliable automation components working tirelessly behind the scenes. The pneumatic system plays a key role in rail transit—from door control and braking systems to pantograph lifting, precise control by a solenoid valve is indispensable.

Facing the severe challenges of continuous vibration, shock, wide temperature fluctuations, and electromagnetic interference during train operation, the solenoid valve is no longer a simple actuation component. It is a "silent guardian" that ensures passenger safety and normal train operation. This article will provide a detailed guide on how to choose the most suitable AirTAC solenoid valve products based on the unique demands of rail transit, helping you build a robust and reliable automation solution.

 

The Unique Demands of the Rail Transit Industry

Rail transit places extremely stringent requirements on the performance, reliability, and environmental adaptability of solenoid valves:

  • Extreme Reliability and Safety: The failure of any component can trigger a chain reaction, directly threatening passenger safety. Solenoid valves must have an extremely low failure rate and a long service life.

  • Vibration and Shock Resistance: High-speed train travel involves continuous vibration and track shock. Solenoid valves must have a specially reinforced structure that can withstand high-intensity mechanical stress.

  • Wide Temperature Adaptability: Rail vehicles operate in various climates worldwide, requiring solenoid valves to function stably in a wide temperature range, from -40°C to +70°C or even wider.

  • Electromagnetic Compatibility (EMC/EMI): With the high density of electronic devices on a train, electromagnetic interference generated by the solenoid valve coil must be effectively suppressed to ensure the normal operation of other sensitive electronic systems.

  • Long Life and Low Maintenance: Due to high maintenance costs and limited downtime, solenoid valves must have a cycle life of tens of millions of cycles and be maintenance-free or require minimal maintenance.

 

Key Technical Parameters for Rail Transit Solenoid Valves

To address these challenges, when selecting a solenoid valve, you must focus on the following key technical parameters:

  • Vibration and Shock Resistance: Must meet industry standards such as EN 61373 to ensure valve connections do not loosen or performance does not degrade in a vibrating environment.

  • Protection Class (IP): For solenoid valves installed under the carriage or on the exterior, the protection class must be at least IP65 or higher to prevent dust and water ingress.

  • Operating Temperature Range: Ensure the product's rated operating temperature covers the actual environment in which the vehicle operates.

  • Coil Technology and Voltage: A safe voltage of DC24V is commonly used, and the coil is required to have excellent electromagnetic compatibility (EMC) and low power consumption.

  • Long-Lasting Seals: Seals must be made of special materials that are resistant to low temperatures and wear to adapt to wide temperature differences and high-frequency actions.

  • Compactness and Modularity: Space inside vehicles is limited, so compact and modular valve manifold systems are the ideal choice.

 

Recommended AirTAC Solenoid Valve Models for Rail Transit

With its stringent manufacturing standards and excellent quality, AirTAC offers several ideal solenoid valve products for the rail transit industry.

1. AirTAC 4V/4A Series (Specially Customized Models)

This series is an outstanding representative of general-purpose solenoid valves that can be specially customized to meet the high demands of rail transit.

  • Reason for Recommendation: AirTAC can provide customized services for the 4V/4A series, such as reinforced anti-vibration coils, special seals, and wide-temperature coils. This allows a general-purpose product to be perfectly adapted to the extreme operating environment of rail vehicles while maintaining high reliability. Its robust structure and reliable performance make it an ideal choice for systems like doors and steps.

  • Typical Applications:

    • Subway and high-speed train door control

    • Train step and pneumatic handrail control

    • Pneumatic control inside the carriage

 

2. AirTAC 4M Series Valve Manifold System

The valve manifold is a perfect solution for complex automation systems that require centralized control.

  • Reason for Recommendation: In rail transit, there are numerous actuators to control. The 4M series valve manifold can integrate multiple valves onto a single module, greatly simplifying wiring and tubing connections. This system can be installed in a dedicated anti-vibration control cabinet, making maintenance easier and providing excellent electromagnetic compatibility, making it the preferred solution for centralized control.

  • Typical Applications:

    • Pneumatic control modules for train braking systems

    • Pantograph lifting system control

    • Pneumatic control of bogie and suspension systems

 

3. AirTAC VFS Series Solenoid Valve (High Flow and Reliability)

This series is known for its powerful flow capacity and outstanding reliability.

  • Reason for Recommendation: For applications that require driving high-power actuators or rapid charging/discharging of airflow, such as pantographs or certain braking systems, the VFS series is the ideal choice. It provides a larger effective area than standard valves, ensuring a fast and accurate response to control commands.

  • Typical Applications:

    • Main valves for train braking systems

    • Emergency lifting and lowering control of pantographs

 

Building a Complete Rail Transit Solution

Selecting the right solenoid valve is a critical step, but to ensure the system operates continuously and efficiently in the harsh environment of rail transit, you also need a complete solution. This includes: using AirTAC Air Preparation Units (F.R.L.) with wide-temperature and anti-vibration characteristics; using highly durable, low-friction AirTAC cylinders; and choosing high-protection-class fittings and tubing that meet industry standards.

AirTAC solenoid valves, with their exceptional robustness, high reliability, and adaptability to extreme environments, have earned widespread trust in the rail transit sector. By making the correct selection, you can inject powerful momentum into your trains, ensure operational safety, and achieve a dual increase in efficiency and lifespan.

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