Components that degrade in fuel exposed environments, when located inside of the fuel tank, may break off and create FOD that clogs fuel pumps. Thus, it is necessary to verify the performance of any secondary support product prior to use in these environments.
For the fuel immersion test, the specimen are tightened around a mandrel and submerged in fuel for 1080 hours. After immersion, a visual inspection is performed for any cracks, distortions, breaks or separation of the fastener head from the lace. Additionally, for MIL-DTL-32554 components, the locking device is also examined for any releasing of the lace. The specimen are then subjected to the tensile strength test.
Parameters that can be adjusted for this procedure include but are not limited to:
- Elevated temperature
- Fuel type
- Post fuel exposure assessment method
- Exposure duration
See here for other fuel immersion type tests.