KF (QF) Flanges

Manufactured using 304L stainless steel, KF flanges, commonly known by International standards Organization as Klein Flansche (KF) fittings, are used in vacuum piping and high vacuum chambers (10-8 Torr). The 304L stainless steel material makes the flanges ideal for systems with extreme temperatures and corrosive environments. Flanges operate in temperature from 0°C through 180°C and pressures from 760 Torr (103mbar) to less than 1 x 10-8 Torr (1 x 10-8 mbar). Generally, KF (QF) flanges are considered a commodity; and the vacuum industry has all but standardized these flanges. Therefore, most manufacturers’ flanges mate and seal with competitors.

KF Flanges are genderless by design and use a rubber/elastomeric o-ring in a centering ring to seal the connecting flanges. The flanges are held together by a clamp that surrounds the joined flanges. By tightening the wing-nut, lever, bolt or thumbscrew, the clamp creates a leak-tight connection sealing the flanges. Flanges are sized by the largest nominal ID tube welded to it.  KF (QF) flanges are also available in Aluminum or Brass for general applications.