Flange Assembly

The CF flange (originally called ConFlat) is a sexless design where both flanges are identical. Typical flange materials are austenitic stainless steel types 304L, 316L, 316LN, and surface hardened aluminum (made from a weldable Al alloy). The seal mechanism is a knife-edge that is machined below the flange's flat surface. As the bolts of a flange-pair are tightened, the knife-edges make annular grooves on each side of a soft metal gasket. The extruded metal fills all the machining marks and surface defects in the flange, yielding a leak-tight seal (Figure 1). The CF seal operates from 760 Torr (1013 mbar) to < 1 x 10-13 Torr (