Measured Leak Rate of Ammonia Through an Epoxy/Stainless-Steel Patch
Abstract
A program has experienced pitting corrosion in anhydrous ammonia-charged loop heat pipes. Areas of each loop heat pipe with increased risk of pitting corrosion were previously identified with X-ray image analysis and patched with a formed stainless-steel cap, bonded with a space-approved epoxy. To assess the lifetime of the patch and sensitivity to manufacturing variation, simulated leaks in circular aluminum discs were patched with several different variants on the same epoxy-stainless materials system. The patches were aged at elevated temperature to accelerate degradation phenomena. No gross failures of the patches were observed in four weeks of testing. No significant difference was observed between the aged bonded material at 353K, 393K, or a freshly prepared patch. Infrared detection of ammonia leaking through the patch suggests that a loss rate of 0.16 +/- 0.04 mg of ammonia per year will occur through the simulated leaks with primed patches.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 10, 2007
- Accession Number
- ADA474731
Entities
People
- B. B. Brady
- J. D. Desain
- T. J. Curtiss
Organizations
- The Aerospace Corporation