COMPLIANT HIGH TEMPERATURE SEALS FOR DISSIMILAR MATERIALS

摘要

A high temperature, gas-tight seal is formed by utilizing one or more compliant metallic toroidal ring sealing elements, where the applied pressure serves t o activate the seal, thus improving the quality of the seal. The compliant nature of the sealing element compensates for differences in thermal expansion between the materials to be sealed, and is particularly useful in sealing a metallic member and a ceramic tube a rt elevated temperatures. The performance of the seal may be improved by coating the sealing element with a soft or flowable coating such as silver or gold and/or by backing the sealing element with a bed of fine powder. The material of the sealing eleme nt is chosen such that the element responds to stress elastically, even at elevate d temperatures, permitting the seal to operate through multiple thermal cycles .