Gold wire seal

Exhibit no. 620

Gold wire seals (O-ring style) are used in ultra-high vacuum regions of mass spectrometers to connect flat flanges that need to be occasionally heated. Gold is very soft, ductile, and can be baked because it does not oxidize at high temperatures. During assembly, gold adapts to the microstructure of flange surfaces to create an ultra-high vacuum-tight connection. The gaskets are usually fabricated from 0.5 or 1.0 mm high-purity wire by fusing its ends. Since the seals can be used only once, gold gaskets are most suitable for semipermanent seals that do not need to be opened too often.