Air brake systems are a core component of many heavy vehicles, such as trucks, buses, and construction machinery. In these systems, air brake hoses play a vital role, responsible for delivering compressed air to trigger the brake operation. Air brake hoses must not only withstand the delivery of high-pressure air, but also maintain reliable performance in extreme temperatures. This article will explore how the design of air brake hoses affects their performance in high pressure conditions and extreme temperatures, and explain why these designs are critical.

1. Design requirements under high pressure conditions

The operating pressure of air brake systems is usually high, especially in the case of heavy vehicles, long-term operation or frequent braking. Brake hoses need to be able to withstand this high pressure without rupture or leakage. Therefore, the design of air brake hoses must include the following key elements:

Strength of inner wall material: The inner wall of air brake hoses is usually made of high-strength synthetic rubber or polymer materials, which can effectively withstand the high pressure of internal airflow. The material of the inner layer must not only be pressure-resistant, but also have excellent anti-aging, anti-wear and chemical corrosion properties.

Reinforcement layer design: To further enhance the pressure resistance of the hose, many high-performance air brake hoses have added reinforcement layers outside the inner layer. These reinforcement layers are usually made of high-strength fiber braided or wire braided materials, which can greatly improve the hose's tensile and pressure resistance. The braided layer effectively disperses the internal pressure and reduces the risk of damage caused by pressure concentration.

Wall thickness: The thickness of the hose directly affects its pressure resistance. Thicker hose walls can provide better pressure resistance, but it is also necessary to find a balance between flexibility and weight. In hose design, the appropriate wall thickness is usually determined based on the pressure requirements of the actual use environment.

Strength of the connection interface: The connection end of the hose is the part where the pressure is most concentrated. When designing, ensure the sealing and strength of the interface. The interface usually uses high-quality metal materials and adopts a tightening design to prevent leakage or breakage under high pressure.

2. Design requirements under extreme temperatures
In addition to high pressure conditions, air brake hoses also need to maintain stable performance under extreme temperature environments. The temperature adaptability of air brake hoses is mainly reflected in the following aspects:

High temperature resistance: In the case of long-term driving or frequent braking, the air temperature in the air brake system may rise rapidly. In order to prevent the high temperature from softening or aging the hose, materials with good heat resistance are needed in the design. Common high temperature resistant materials include silicone, fluororubber and polyurethane, which can maintain structural stability at high temperatures and prevent the hose from losing function due to thermal expansion and contraction.

Low temperature resistance: In cold environments, air brake hoses need to maintain flexibility to avoid hardening, cracking or brittle fracture of the material due to low temperature. Therefore, the outer and inner materials of the air brake hose must have low temperature resistance. In particular, synthetic rubber and polymer materials usually use additives to improve their flexibility at low temperatures to ensure that the hose can work smoothly under low temperature conditions.

Temperature change adaptability: In actual use, air brake hoses may experience rapid temperature changes. The hose material needs to have good thermal stability and thermal shock resistance to prevent expansion or contraction under large temperature fluctuations, thereby affecting the sealing performance and overall structure of the hose.

3. Advantages of multi-layer composite structure
In order to provide better protection under high pressure and extreme temperature conditions, many air brake hoses adopt a multi-layer composite structure design. This design usually includes multiple composite layers of different materials, each of which can play a different role:

Inner layer: responsible for resisting the high pressure of compressed air, and has anti-aging and anti-corrosion functions.
Reinforcement layer: improves the hose's pressure resistance and enhances its tensile strength.
Outer layer: provides additional protection against external environmental influences such as wear, UV radiation and chemical erosion. The outer layer material generally uses synthetic rubber or polymer materials that are resistant to high temperature, cold, oil and UV to ensure the long-term service life of the hose in various harsh environments.
4. Environmental adaptability and durability
The design of air brake hoses must not only adapt to high pressure and extreme temperatures, but also have good durability and adaptability. The following aspects are often considered in hose design:

Abrasion resistance: Since air brake hoses may rub against vehicle components or the ground during use, abrasion resistance is an important consideration in the design. Highly wear-resistant materials can extend the service life of the hose and reduce the frequency of replacement.

UV resistance: If the hose is exposed to sunlight for a long time, UV rays may cause material aging and performance degradation. Therefore, the outer material usually needs to have UV resistance to ensure the stability of the hose after long-term use.