Aircraft Seals and Gaskets: Their Materials and Applications

Seals are used to join components together to prevent the passage of materials, gaskets seal the gap between two or more mating surfaces to prevent the entrance or exit of fluids, contaminates, and other substances. Despite having very similar applications, seals and gaskets are separate components that are used for different reasons. In this blog, we will discuss aircraft seals and gasket designs in more detail, allowing you to better understand the materials that make such components up and how they are implemented on assemblies.

In order to optimally fill the gaps and openings of various structures while preventing any leakage or passage of materials, most seals and gaskets are made from elastomers. Elastomers are rubber substances that maintain elasticity while stretching, and they are often made under various standards for aviation use. Typically, the most common types of elastomers used include silicones, fluorosilicones, FKM, neoprene, EPDM, urethanes, and polyurethanes. In some instances, a different material may be needed, such as airframe structures taking advantage of fiber-reinforced plastic parts to ensure ample vibration control.

Aircraft rubber gaskets are commonly produced under the ASTM D2000 standard, that of which was originally made for the automotive industry. While being a common classification for rubber, some aviation and aerospace materials may be constructed to meet more rigorous standards and specifications, such as Aerospace Materials Specifications (AMS) by SAE International or the MIL-DTL-25988 military specification. Whether an aircraft is to be used for commercial, civil, or military applications, determines the unique specifications of seals and gaskets. Furthermore, certain assemblies may require specifications like oil or fuel resistance as well.

Original equipment manufacturers (OEMs) may also have their own established standards for the materials used to create seals and gaskets, especially when there is potential exposure to flames, toxic materials, or smoke. For instance, Boeing has established a number of specifications for their aircraft, and gaskets/seals dealing with smoke will need to be made under BSS 7238 while those in dealing with toxicity will be made under BSS 7249. As aircraft become increasingly electrified with more and more powered instruments and systems, some aircraft need EMI gaskets with certain levels of shielding.

While sharing many of the same specifications and materials, gaskets and seals serve different roles in an assembly. With a gasket, a flat surface gap between two or more components can be sealed. Generally, the gasket is placed between the components, compressing to fill any irregularities while providing a static seal. Standard seals, meanwhile, are placed between engine parts, shafts, and pumps that are in motion, rather than being static. While gaskets are shaped in different ways to accommodate an assembly, seals are often flat and rounded. Seals also often have a slightly tilted lip, ensuring that any drips that make it past the first barrier are met with a second barrier. To install a gasket, it will often be placed between the components, while a seal can be installed by being pressed and tapped with a hammer, and lubrication is required in certain instances.

Whether you find yourself in need of aircraft rubber gaskets or seals, Aviation Domain 360 is your sourcing solution with an unmatched catalog of top-quality items. Explore our various part catalogs as you see fit, and our team is always at the ready to assist you through the purchasing process however necessary. Even if you happen to be facing a time constraint and require parts fast, our supply chain network ensures expedited shipping times for domestic and international orders alike. Experience the future of part procurement today when you get in contact with an Aviation Domain 360 representative. 

1. nortan ted
2. Posted on April 6, 2022
aerospace