US Patent 7819382 Temperature and pressure responsive seal

A seal for a vessel is disclosed which militates against a leakage of fluid during expansion and contraction of the vessel due to changes pressure and temperature. Inner sealing surfaces of the seal form substantially fluid-tight seals in response to at least one of temperatures below a predetermined temperature and pressures below a predetermined pressure and outer sealing surfaces of the seal form substantially fluid-tight seals in response to at least one of temperatures above the predetermined temperature and pressures above the predetermined pressure.