Three Sealing Materials to Make Your Aircraft Sustainable Aviation Fuel Ready
The aviation industry’s commitment to Sustainable Aviation Fuels (SAF) to reduce carbon emissions is clear, but there’s a catch. What’s good for the planet can be tough on the aircraft fueling systems and their sealing technologies.
The unique chemistry of SAF raises questions about how it interacts with seal materials. That’s why Greene Tweed has begun testing a range of its Fluorocarbons (FKM) and Fluorosilicone (FVMQ) materials in select SAF types under various temperature and aging conditions. “Solving our customers' toughest problems is what drives us every day. That’s why, when we saw the need for sealing solutions that can handle SAF, we set out to test and innovate to help the aviation industry take flight toward sustainability,” says Elizabeth Sassano, Director, Strategy and Business Development at Greene Tweed.
With this in mind, Greene Tweed’s Advanced Technology Group, a team of scientists and engineers dedicated to developing new sealing and thermoplastic composite solutions for demanding applications, set out to conduct effective tests to uncover the materials that can withstand the chemical, thermal, and mechanical conditions that SAF presents. “We evaluated compatibility in multiple SAF formulations, and resistance to fuel switching recovery,” explains Ronald Campbell, Technology Manager at Greene Tweed.
After extensive testing, here are the three FKM materials that stood up to the challenges of SAF:
- Fusion® 731: Trusted for Legacy Aerospace Platforms
Fusion® 731, a black Type1 FKM polymer, demonstrated compatibility with SAF while maintaining durability at high temperatures. Originally engineered for Aerospace Material Specification (AMS) 7276 specifications, it has a proven track record in several existing aerospace fuel systems. Its key features include:
- Operating Temperature Range: From -22°F to 450°F (-30°C to 232°C).
- SAF Compatibility Finding: It showed exceptional results during fluid switching evaluations, maintaining integrity in SAF and blended fuels.
- Fusion® 772: Optimized for Modern Fuel Systems
Engineered for modern aerospace fuel systems, Fusion® 772 is a type 3 FKM seal, meeting AMS 7287 standards. Unlike traditional materials, this elastomer excels under the demanding thermal and chemical stresses introduced by SAF. It offers:
- Expanded Temperature Range: From -40°F to 450°F (-40°C to 232°C).
- SAF Compatibility Finding: It excelled in both 100% SAF and 50/50 fuel blends.
- Fusion® 665: Designed for Ultra-Low-Temperatures
Fusion® FKM 665, an ultra-low-temperature and chemical-resistant elastomer, is specifically formulated to meet and exceed the requirements of AMS 7379 and AMS 7410. It has an extremely low compression set, broad chemical compatibility, and good abrasion resistance, thus overcoming the limitations of existing NBR, standard FKM, and FVMQ solutions. With a wide operating temperature range, it performs well at low temperatures with zero leakage. Its key features include:
- Outstanding low-temperature sealing: From -70°F/-57°C to 450°F/232°C
- SAF Compatibility Finding: The favorable compression set performance of 665 compound is not impacted when used with 100% SAF and associated blends.
The results of the testing showed that the three FKM elastomers performed remarkably well in three different Synthetic Paraffinic Kerosene and one Synthetic Aromatic Kerosene, when exposed to elevated temperatures during simulated "dry-out" conditions, maintaining their integrity and functionality. This highlights their durability, adaptability, and suitability for challenging conditions.
“Our tests and their results speak volumes about the robustness of Fusion® 731, 772, and 665. As our customers adopt SAF to slash emissions, our materials are well prepared to to future-proof their aerospace systems,” sums up Sebastian Dubois, Sales Director, Aerospace and Defense at Greene Tweed.
Partnering for the Future of Sustainable Aviation
Are you ready to future-proof your aerospace systems? Greene Tweed’s expert team has tested the compatibility of its FKM seals with SAF and is here to guide you by integrating SAF-ready sealing solutions tailored to your requirements. Contact us today to learn how Greene Tweed can support your SAF projects.