CF Flange 2.75" (DN 40 CF), Bored for 1.5" Tube with Through Holes, Rotatable 304L

CF flanges are perfect for ultra-high vacuum (UHV), corrosive environments, and high temperature applications. These knife-edge flanges can be used with a metal gasket (typically copper) to create a leak-tight UHV capable seal that can operate down to 10^-13 Torr (10^-11 Pa). Ideal Vacuum CF flanges are made of corrosion-resistant stainless steel and can be heated to 842° F (450°C) for bake-out.

Metal gaskets are considered single-use and must be replaced after a disassembly to achieve optimal performance. For pressures around 10^-8 Torr and higher, CF flanges may also be sealed with reusable seals such as Viton™ FKM* for convenience. Below 10^-8 Torr, permeation leakage through elastomer seals will have a significant negative effect on ultimate pressure.

CF flanges are available in fixed and rotatable configurations with tapped or through holes for bolted assembly. Flanges with through holes are typically assembled with fine pitch thread 12-point bolts into a flange with tapped holes. A through-hole flange may also be secured to a second through-hole flange using plate or hex nuts on the backside of the interface.

Common Dimensions:

• Flange Size CF 2.75" / DN 40 CF
• Outer Diameter (Ø OD) = 2.75" (69.9 mm)
• Bolt Circle Diameter (Ø BC) = 2.31" (58.7 mm)
• Ø Through Bore = 1.38" (35.05 mm)
• Ø Counterbore = 1.5" (38.1 mm)
• Tube Size = 1.5" (38.1 mm)
• Bolt Hole Size (A) = 1/4"-28
• Thickness (B) = 0.49" (12.5 mm)

Flange Specs:

• Six 1/4"-28 Through Holes
• 304L Stainless Steel
• Rotatable

*Viton™ is a registered trademark of The Chemours Company.