A Copper Gasket is used to mate two Conflat CF vacuum flanges together. These conflat copper conflat gaskets fit a conflat flange size of 2 1 8 inches.
The gasket material sealing two flanges determines the joint s maximum temperature and, to an extent, the base pressure of the vacuum volume.
Metal gaskets are impermeable to gases and withstand moderately high temperatures indefinitely. The normal gaskets for stainless steel CF flanges are punched from 1 4 hard, high purity, oxygen free OFHC copper stock.
The gaskets are then chemically cleaned and processed to minimize scratches and burrs. ConFlat CF flanges are used for ultra high vacuum applications.
These fittings use a copper gasket and knife edge flanges to achieve the high vacuum seal and can operate down to 10 13 torr 10 11 Pa and can be heated to 450 C for bake out.