CF knife edge flanges are widely used in ultra-high vacuum systems by deforming oxygen-free copper gaskets (or other soft metals) by squeezing them with the knife edge. Due to all-metal seal, CF Flange can withstand high temperature baking, and can achieve extremely high vacuum levels, ~10E-12 mbar, with proper operation.

CF welding flange includes non-rotatable flange(fixed flange) and rotatable flange. The non-rotatable flange is an integrated structure, while the rotatable flange consists of two parts, an inner weld ring and outer bolt ring,  the outer bolt ring is bolted to the flange and the inner weld ring is sealed by the knife edge .

There is CF blind flange used to insulate the neighbor systems, which is easily disassembled with bolt fixing.