ISO Flange

SO flange is sometimes called LF, LFB or MF flange. The ISO flange is a large-sized soft-sealing flange similar to the KF flange.

They also use a centering ring with a rubber O-ring between the two flanges to achieve vacuum sealing. ISO flange has two different structural types, they are ISO-K/ISO-LF and ISO-F/ISO-LFB. When the KF flange is called the ISO-KF flange, we should note that it is different from the ISO-K or ISO-F flange.

There is a circular groove on the tubing side of the ISO-K flange, and two identical flanges are fixed together through a claw clamp. The ISO-F looks completely different, it has bolt holes in it. After aligning the two ISO-F flanges with the bolt holes, pass the bolts through the two flanges, add gaskets, and connect them with nuts.

There is also a special case where need to connect ISO-K and ISO-F that look completely different. In this case, you need to use a half-claw clamp.

ISO flange sizes range from ISO63 to ISO500, and all sizes are ISO63, ISO80, ISO100, ISO160, ISO200, ISO250, ISO320, ISO400, ISO500 and ISO630. The size of the ISO flange depends on the nominal inner diameter of the vacuum flange.

ISO flanges are suitable for pressure ranges from atmospheric pressure to 1 × 10-8 Torr or mbar, and temperature ranges from 0 to 180 degrees Celsius.

The most commonly used materials for ISO flanges are stainless steel 304 and 316L.

Of course, we also provide some other materials for customers to choose from.