FIXED & EXPANSION CONNECTORS FOR COMPOSITE CRYOPIPE

This Phase II research eill remove the two major barriers to converting metal alloy rocket engine lines and ducts to polymer matrix composites (PMC). These barriers are (1) unreliable composite flange joints, and (2) heavy, expensive metal alloy bellows.The objectives are to cut both launch weight and cost by half. Dynamic Polymer Composite (DPC) connectors clamp fixed pipe joints with a large prestress when heated. They eliminate flanged joints adn join dissimilar materials with a smooth stress flowthat is stronger than the pipe itself. DPC expansion joints replace alloy bellows. In Phase I both were validated by actual cryogenic pressure tests using prototypes not optimize for low temperature. Prestress was found to eliminate cryo delamination.Fixed joints were tested to 4,500 psi. Expansion joints demonstrated an axial travel of three inches (75mm). Using existing space quailified materials, Phase II will develop and cryo test a series of DPC connections designed and scaled for one of theseven current rocket engines in a cyclical, cryogenic enviroment. Test and modeling data will be integrated for transfer of the technology to contractors in preparation for PhaseIII flight-testing. A large composite pipe producer is a commercial partenerfor use in oil and gas fields. $300,000 has been committed. Eight market segements with a potential of $200 milliona year have been identified. Alloy rocket fuel systems are $1.6 billion a year worldwide.