A Unique Metal-to-Metal Seal for Separable Joints

Environmental conditions in aerospace systems demand the use of metallic seals and the complete absence of leakage. A unique metal-to-metal seal called the Bobbin seal utilizing the elastic and plastic response characteristics of the seal structure is described. Experimental evaluations with 250 specimens, with 99% sealing helium at leakage rates less than 7 × 10⁻⁷ atm cc/sec, indicate that the Bobbin seal can overcome almost any problem of leaking joints in missile, aerospace, or aircraft systems. Results obtained with various materials, in a broad environmental spectrum, with tube sizes up to 16 in. are described.