KF (QF) Flanges & Components

KF flanges (QF) are a type of flange system commonly used in vacuum applications. They come in sizes 10, 16, 25, 40, 50 and are widely used in both rough and fine vacuum environments. KF flanges have flat sealing surfaces and conical flange sides. They are connected using O-rings with centering rings and secured with clamping chains, clamping rings, or quick-release clamps. Elastomers like NBR or FKM (Viton®) are commonly used as sealing materials. For special requirements, edge seals made of PTFE or aluminum can also be used.

KF flanges provide reliable vacuum seals with a leak rate typically specified at 1·10−9 mbar·l/s. They are suitable for various vacuum applications but have pressure limitations due to gas permeation through elastomer seals.