ISO Components

ISO-KF standard for clamp connectionsThe ISO-KF standard for clamp connections (DIN 28404, ISO 1609) is the standard connection for vacuum pipes starting from the nominal diameter DN63 and larger used in fine and high vacuum. The various possibilities of connection between two flanges are shown in the figures.

Connection with claw clampsFunctional Principle

ISO-K: Two single flanges are connected with the help of claw clamps. The flanges have a groove on the back in which the claw clamps are hooked which press the flanges together. Such as KF connections there is a sealing with centering ring and O-ring between the flanges. Mostly an additional trapped centering ring is used which produces an assembly with constant distance.

Connection with screwsISO-K flanges with holes are called ISO-F flanges and the sealing is the same as for ISO-K flanges. Both flanges can be easily combined with each other. An ISO-K flange can be transformed into a rotatable ISO-F flange by means of a rotatable bolt ring with retaining ring. Screws hold the flanges together.

Combination ISO-K / ISO-F1ISO-F flanges are commonly used for wall mounting or with gate valves. An ISO-K flange can be fastened thereon with the help of claw clamps. Claw clamps are available for tapped blind holes as well as for through bolt holes.

It is possible to connect the flanges without a centering ring if the o-ring lies in a groove on the flange. But claw clamps with mated length have to be used in this case.