Patent ID: 7581765

Claim:
A seal assembly comprising: (a) a first seal element having a first face, a second face generally parallel to the first face, and an axis orthogonal to the first and second faces, wherein the first seal element is made of a first material having a first coefficient of thermal expansion; (b) a second seal element having a first face, a second face generally parallel to the first face, and an axis orthogonal to the first and second faces that is parallel with or coincident with the axis of the first seal element, wherein the second seal element is made of a second material having a second coefficient of thermal expansion, and wherein the first face of the second seal element is in forcible contact with the second face of the first seal element, the second material is selected from the group consisting of aluminum oxide, zirconium oxide, cerium oxide, magnesium oxide, silicon carbide, silicon nitride, mixed metal perovskites, (La x Sr 1-x ) y CoO 3-z (wherein 1.0 >×>0.4, 1.02≧y>1.0, and z is a number which renders the composition of matter charge neutral), and (La x Ca 1-x ) y FeO 3-z (wherein 1.0 >×>0.5, 1.1≧y>1.0, and z is a number which renders the composition of matter charge neutral); and (c) a clamping element adapted to urge the first seal element axially toward the second seal element, wherein the clamping element has a first segment in forcible contact with the first face of the first seal element, a second segment in forcible contact with the second face of the second seal element, and a connecting segment between and attached to the first and second segments, wherein the connecting segment has a central portion extending between planes formed by the first face of the first seal element and the second face of the second seal element, is generally parallel to the axes of the first and second seal elements, and is made of a third material having a third coefficient of thermal expansion; wherein the third coefficient of thermal expansion is intermediate the first and second coefficients of thermal expansion.