What does CF mean in reference to vacuum chambers?

Question

I'm seeing this on a lot of the vacuum chambers, some say they have "Multi-CF fittings"

Answer 1

*ConFlat, a type of vacuum flange .

*For ultra-high vacuum applications, there are ConFlat (CF) flanges that use a copper gasket and knife-edge flange to achieve the vacuum seal.[3] Conflat flanges operate down to 10-13 torr (10-11 Pa) pressure and can be heated to 450 °C for bake-out. North American flange sizes are given by flange outer diameter in inches: 1⅓ ("mini"), 2¾, 4½, 6, 8, 10, 12, 13¼, 14 and 16½. In Europe and Asia, sizes are given by tube inner diameter in millimeters:

DN16

DN40

DN63

DN100

DN160

DN200

DN250

Answer 2

It is used to signify "ConFlat" flange...

CF

For ultra-high vacuum applications, there are ConFlat (CF) flanges that use a copper gasket and knife-edge flange to achieve the vacuum seal.[3] Conflat flanges operate down to 10-13 torr (10-11 Pa) pressure and can be heated to 450 °C for bake-out. North American flange sizes are given by flange outer diameter in inches: 1⅓ ("mini"), 2¾, 4½, 6, 8, 10, 12, 13¼, 14 and 16½. In Europe and Asia, sizes are given by tube inner diameter in millimeters:

DN16

DN40

DN63

DN100

DN160

DN200

DN250