• Component Type
    Weld Stub Flange with Weld Prep
  • Series
    Series 88
  • Flange Type
    CF Ultra High Vacuum
  • Flange Size
    1.33 in.
  • Rotatable Flanges
  • Bolt Hole Type
    Thru Hole
  • Material
    304 Stainless Steel
  • Tube OD
    0.5 in.


Standard Flange for UHV Applications

CF-style ConFlat flanges are the standard for ultra high vacuum (UHV) applications. They use a flat gasket placed between two knife edges to provide a vacuum tight seal. Mating flanges have identical profiles, eliminating the need to store two types or worry about compatibility.

Made with very high purity stainless steel and meticulous cleaning procedures, our CF components are suitable for use in the ultra high vacuum applications to below 10-13 Torr and in temperatures from -196° to 500°C. The material characteristics of the flanges, seals, screws, and nuts are selected to provide high performance throughout a wide temperature range. Rotatable and nonrotatable flanges in sizes from 1-1/3 to 4-5/8 in. are available with several bore sizes to fit a range of tube diameters.

Joining CF Flanges

ConFlat flange components are joined by inserting a gasket seal between the two CF flange faces, then securing the assembly with bolts. Flange bolts should be tightened diagonally for a secure vacuum seal. The foolproof CF design provides leak tight joints consistently.

A variety of sealing hardware is available, such as plate nuts, dodecagon bolts, Viton® seals, and individually wrapped copper and silver-plated copper gaskets protected from corrosion and mechanical damage.

CF flanges remain leak tight even after repeated cycling of the temperature over a wide range. The availability of both tapped and clearance bolt holes gives great flexibility.

The rotatable versions simplify alignment with the bolt holes of other system components and give infinitely rotatable joints. All fittings have at least one rotatable flange for easy alignment. Nonrotatable flanges provide better knife edge protection.

CF Flange Gasket Options

Flange gaskets make these CF flanges self-centering and the standard leak grooves simplify troubleshooting and gasket removal.

OFHC copper gaskets are cleaned, insured to be scratch free, individually sealed, and ready for use. Individual packaging protects flange seal surfaces.

The Viton CF gasket feature a unique notching in the design, allowing less outgassing than most elastomer seals.

Flange Size Gasket OD Gasket ID Maximum Torque
1 1/3 inch 0.84 in. (21 mm) 0.64 in. (16 mm) 5 ft⋅lbf
2 1/8 inch 1.29 in. (33 mm) 1.01 in. (26 mm) 16 ft⋅lbf
2 3/4 inch 1.90 in. (48 mm) 1.45 in. (37 mm) 16 ft⋅lbf
3 3/8 inch 2.43 in. (62 mm) 2.01 in. (51 mm) 26 ft⋅lbf
4 1/2 inch 3.24 in. (82 mm) 2.51 in. (64 mm) 26 ft⋅lbf
4 5/8 inch 3.60 in. (91 mm) 3.01 in. (76 mm) 26 ft⋅lbf