Vacuum flange
Vacuum flanges are used for releasable connection of vacuum vessels. Depending on the requirements with respect to tightness, bakeout, stability, corrosion resistance and diameter are different standardized parts.
Types of flanges
Small flanges
Small flange - speed connections ( "ISO -KF " ) are available in nominal sizes 10, 16, 20, 25, 32, 40 and 50 and the compounds most commonly used in the rough and medium vacuum range. The nominal diameters of 10, 16, 25 and 40 are the so-called preferred nominal sizes according to ISO recommendation. The dimensions are set in DIN 28403 and ISO 2861/1. The two small flanges to be joined are sealed by an O- ring with outer or inner centering ring and pressed together by a clamping ring or quick release clamp. As sealing material usually an elastomer such as Nitrile, Neoprene or Viton is used for special requirements and metal seals can be used.
Clamping flanges
Clamp flange connections (" ISO - K") are similarly used as KF connections, but here the compressibility is achieved by clamping screws or Collar flanges. They are used for larger diameter than KF and are compatible with the ISO Schraubenflanschsystemen -F. The dimensions are set in DIN 28404.
CF Flanges
CF flanges are based on the Conflat flanges from Varian. They are used for connections from ultra-high vacuum ( UHV) components, flanges made of stainless steel, the sealing material is usually copper. The flanges are equipped with cutting edges, which are pressed in one piece in the sealing material when tightening the connection, and thereby sealed. Metallic seals may be used by the permanent set only once. However, elastomeric seals may be used as temporary structures. Advantage of the CF connections is the high bakeout temperatures and good sealing values .
A selection of conventional CF flange sizes ( all dimensions in mm ):
Penetrations
A frequently used type of (blank ) flange is the implementation. This is used to build several more necessary for the process or experiment, compounds such as power supply, power supply with gases, coolants, the implementation of measurement signals from the vacuum vessel, or mechanical manipulation of bodies in a vacuum.