CF Flanges and Fabrications
All CF flanges are manufactured from specially selected, high quality stainless steel - 304L (1.4306) or the higher specification 316LN (1.4429). These materials being the accepted standards throughout the UHV vacuum industry. Both stainless steels are low carbon varieties designed to avoid inter-granular corrosion after welding. 316LN has the additional advantages of a lower magnetic permeability, harder knife edge, and high temperature H2 degassing at up to 950ºC. Full traceability is available on all materials used. Protective mouldings and suitable packing ensures that the flanges reach the customer in perfect condition for use on UHV equipment. The product range includes blank, bored and rotatable flanges in all of the internationally approved sizes. Other sizes and special flanges are available to order.
The CF series flange utilise the well proven captured copper gasket sealing principle which is now almost universally used in the UHV industry. The seal - an OFHC copper gasket - is held between the knife edges of a pair of CF flanges. On tightening the retaining bolts, the knife edges cut into the gasket and force the copper both axially as well as radially outwards to the flange. The material is thus enclosed and cannot flow, even at high bakeout temperatures. This sealing method has a maximum bakeout temperature of 450ºC and is suitable for vacuum applications to 10-12 mbar.
