Provac offer a range of Conflat® flanges which are compatible with flanges made by other leading manufacturers. All CF flanges are manufactured from specially specially selected, high quality stainless steel and are individually processed through our cleaning facilities. Only 304L (1.4306) or the higher performance 316LN (1.4429) stainless steels are used in the manufacture of CF flanges. These materials begin the accepted standards throughout the UHV/vacuum industry. Both stainless steels are low carbon varities designed to avoid inter-granular corrosion after welding. 316LN has the additional advantages of a lower magnetic permeability, harder knifedge, and high temperature H2 degassing at up to 950°C.
Full traceability is available on all materials used. Protective moulding and vacuum skin 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 450°C and is suitable for vacuum applications to 10-12 mbar.
