Rules of Thumb

How High Altitude Affects Rubber Seals

Engineers and manufacturers who work with rubber seals for aerospace, aviation, or high-altitude applications need to understand exactly how elevation affects seal performance. As the altitude increases, several environmental factors arise that can significantly impact a rubber seal’s integrity and performance.

What Happens at High Altitudes?

At high elevations, two major factors can affect rubber seals:

1. Decreased Atmospheric Pressure: As altitude increases, atmospheric pressure decreases. This reduction in pressure may cause sealed gasses to expand, potentially compromising seal integrity.

2. Temperature Fluctuations: Extreme temperature variations are common at high altitudes, which can impact rubber’s physical properties and performance characteristics.

High Altitude Issues

Gas Expansion and Seal Deformation

When sealed systems ascend to higher altitudes, trapped gasses will expand due to lower external pressure. This expansion can cause:

  • Seal distortion
  • Increased stress on seal materials
  • Potential leak paths

Material Property Changes

Rubber compounds may experience:

  • Reduced flexibility in cold temperatures
  • Accelerated aging due to increased UV exposure
  • Changes in compression set characteristics

High Altitude Solutions 

To ensure optimal seal performance at high altitudes, consider the following:

Material Selection

Choose compounds specifically formulated for high-altitude applications, such as:

  •    Fluorosilicone for extreme temperature resistance
  •    HNBR for excellent compression set properties
  •    Specialty compounds with enhanced UV resistance

Design Considerations: Implement design features that account for altitude-related challenges:

  •    Proper groove dimensions to accommodate material expansion
  •    Adequate compression ratios
  •    Pressure-relief features where necessary

Testing Matters

You should always validate a seal’s performance by simulating high-altitude before use. This ensures a seal’s reliability and helps prevent expensive or dangerous failures in the field.

By understanding these factors and implementing appropriate solutions, engineers can ensure their rubber seals perform reliably even in challenging high-altitude environments.
For more information about high-altitude sealing solutions, please contact Apple Rubber’s engineers.