- Wide range of Imperial and Metric standard sizes.
- All flanges manufactured on computer controlled CNC machines for accuracy.
- Available in 304 or 316LN as standard from stock.
- Low outgassing rates.
- Available with optional tapped holes in most sizes including metric and UNC.
- Special flanges can be made to order.
Introduction
The VG Scienta range of UHV flanges is world renowned both for its quality and range of sizes and materials. The complete range of flanges is fully compatible with the internationally agreed ISO/Pneurop standards and will connect to any other flange that also complies with this standard. For flanges with a diameter greater than 300mm no such standards exist at present. All flange OD dimensions are nominal, actual values are tabulated on page01_02.
The UHV seal is made by trapping a copper gasket between two of these sexless flanges. The flanges have a sharp knife-edge profiled onto their operating face. When joined together with a set of stainless steel connecting bolts these knife-edges cut into the surface of the copper gasket to make a seal that is UHV leak tight. When exposed to bakeout temperatures the shape of the knife-edge ensures that the seal remains leak tight by resisting any differential movements between the copper gasket and the stainless steel flange parts.
Flanges are bolted together with a copper gasket between the knife edges.
‘Fixed’ and ‘Rotatable’
To aid the construction of UHV chambers and components, our flanges are available in both fixed and rotatable notations. Fixed flanges are a single piece machined item with the bolt hole orientation fixed into position once they are welded onto a chamber port or component. Rotatable flanges are made from two pieces with the knife-edge part and external bolt hole ring being separate. Once the knife-edge part is welded in position it is easy to change the orientation of the bolt holes relative to the axis of the port. This makes rotatable flanges ideal for the situations where alignment of a component to a chamber (or another component) needs to be set accurately before the flange mounting bolts are tightened. (Note: Do not match two rotatable flanges at the same joint.)