bulb seals

These Heroes of Flight Keep Things Tight: Bulb Seals for Aerospace 

John StoneTransportation

How does the cabin of a colossal aircraft remain pressurized at dizzying altitudes? What keeps critical fluids contained within complex onboard equipment? The answer might not be what you expect. The bulb seal, a simple but crucial component, is the humble hero that helps keep airplanes flying and equipment running.  

Are bulb seals the right products for your application? Keep reading to learn more and contact The Rubber Group for more information. 

Bulb Seals: The Shape of Success 

Some gaskets are flat. Bulb seals, as their name suggests, have a bulbous profile instead. The bulb, a seemingly simple feature, packs a powerful punch in the world of aerospace. That’s because the design of the bulb supports the formation of a tight seal between mating surfaces under minimal sealing force, or compression. Plus, bulb seals can handle variations in mating surfaces and thermal expansion and contraction of the larger system. 

Sealing at Extreme Temperatures 

From the scorching heat generated by jet engines to the extreme cold of high altitudes, aircraft operate across a wide temperature range. That’s why aerospace bulb seals are typically made from resilient materials, such as silicone, that can withstand these temperature extremes without losing their sealing properties. Silicones can handle consistent temperatures up to 500°F (260°C) and will retain their flexibility at temperatures as low as –120°F (48.9°C). 

Three Aerospace Applications 

The aerospace industry uses bulb seals for environmental sealing, contamination management, and noise reduction.  

Environmental Sealing 

Bulb seals help ensure cabin pressurization by preventing air from escaping the aircraft at high altitudes. Importantly, they also support sealing the radiused corners on airplane doors. 

Contamination Management  

These environmental seals also keep substances outside the aircraft from infiltrating critical systems. This includes the cabin where passengers sit and onboard equipment.   

Noise Reduction  

By dampening vibrations, bulb seals contribute to a quieter, more comfortable cabin. You can enjoy watching your movie, listening to your favorite music, or just relax while flying high.  

Bulb Seals and Material Science 

It’s not just the shape of the seal that determines its effectiveness. The material that’s behind the geometry plays an equally critical role. From materials that allow various sealing forces to materials that can withstand extreme conditions, The Rubber Group has formulations for demanding applications. These materials can also meet aerospace industry, Boeing, and other specifications to ensure the long-term quality of your sealing system.  

Humble Heroes Take Flight 

Bulb seals might not be among an aircraft’s flashiest components, but their importance is undeniable. These seals are silent guardians, helping to ensure the smooth operation and safety of every flight.  The next time you fasten your seatbelt aboard an airplane, take a moment to consider how these humble heroes help keep you safe and comfortable in the skies. 

To learn how The Rubber Group can provide you with aerospace bulb seals, contact us