VTD and A&N are aware of the stringent standards that ultra-high vacuum applications require and select raw materials with this in mind. Flanges up through 4.5″ diameter are made from 304-L stainless steel – a low carbon grade stainless steel noted for high purity and hardness. Low carbon levels mean less inclusions, fewer microscopic leak paths and results in flanges which aid in rapid pump down times in UHV applications. Flanges over 4.5″ and up to 16.5″ are manufactured from cross-forged 304 stainless steel plate. The orientation of the grain of the material in plate is perpendicular to the flange face, which reduces the possibility of leakage from atmosphere to the vacuum side of the flange. The hardness of all material used is constantly monitored to ensure hard, durable knife edges that will not ‘roll over’, and can be used repeatedly.
A complete array of hardware necessary for the assembly of CF flanges and fittings is also available. The copper gasket, which is captured between mating CF flanges, is made from high purity, oxygen free 1/4 hard copper. These gaskets are precisely punched, de-burred, chemically treated and individually packed to eliminate marring the sealing surface prior to use. Re-useable Viton gaskets are also available for leak check use and in unbaked applications. Nuts, bolts and washers are all high tensile stainless steel assemblies and are also available silver plated for applications featuring repeated high temperature baking.
Whatever your application, you can be assured of consistent performance from VTD / A&N components!