ISO KF quick release connections are available in sizes NW10/16 up to NW50 according to ISO. KF NW63 is an additional size, which is only being offered by EVAC with appropriate seals (elastomer, aluminium) and chain clamps.
Generally, an inner- or outer centered elastomer seal (Aluminium seal for special applications) is placed between two flanges and the sealing is achieved via a chain clamp.
Flanges are available in stainless steel as well as in glass (Duran® , quartz).
KF standard is most frequently used for rough- to high vacuum, up to 10E-9 mbar (100 nPa), or peak pressure up to 20 bar (2 MPa), depending on flange diameter and seal material, as well as on geometry of the center ring. While inner center rings are used for vacuum applications, outer center rings are used for overpressure. Combinations of both are available, where both conditions are likely to occur.
Using steel KF flanges, with aluminium edge type seals, vacuum and peak pressure range can be well expanded to 10E-11 mbar (1 nPa) and 50 bar (5 MPa), respectively.