Glass-to-metal seal absorb the stresses from thermal expansion mismatches. Due to its very low vapor pressure, indium finds use in glass-metal seals used in vacuum technology. Gallium is a soft metal with melting point at 30 °C. It readily wets glasses and most metals and can be used for seals that can be assembled/disassembled by just slight heating. It can be used as a liquid seal up to high temperatures or even at lower temperatures when alloyed with other metals (e.g. as galinstan). Mercury is a metal liquid at normal temperature. It was used as the earliest glass-to-metal seal and is still
Minimum design metal temperature that is, according to the low temperature embrittlement range and the charpy impact test requirements per temperature and thickness, for each one of the vessel's components. Minimum design metal temperature MDMT is one of the design conditions for pressure vessels engineering calculations, design and manufacturing according to the ASME Boilers and Pressure Vessels Code. Each pressure vessel that conforms to the ASME code has its own MDMT, and this temperature is stamped on the vessel nameplate. The precise definition can sometimes be a little elaborate, but in simple terms the MDMT is a temperature arbitrarily selected by the user of