Vacuum flanges are semi-permanent connections to join together parts of a vacuum system.   Several vacuum flange standards exist, and the same flange types are called by different names by different manufacturers and standards organisations.

Our sizing guide (see Reference Tables) will help to understand the nomenclature and usage of the main standards:

Klein Flange (KF) or Quick Flange (QF), also known as DN are characterised by their chamfered back and O-ring sealing.

CF Flanges (originally known as ConFlat®) use a copper gasket and knife-edge flange to achieve an ultrahigh vacuum seal.

ISO Flanges are generally larger sized flanges sealed by O-ring.