Fluoroelastomer O-rings, our fluoroelastomer (VIT) Viton O-rings are manufactured from a copolymer of vinylidene fluoride and hexafluoro-propylene. Fluoroelastomer O-rings should be used in systems operated below 10-6 mbar. Fluoroelastomer O-rings take up a set as their operating temperature increases, but this does not affect their sealing properties in vacuum applications. A fluoroelastomer ‘O’ ring will restore to its normal shape after uncompressed exposure to atmosphere: accelerate this process by heating to 150 °C in air. The baking temperature of fluoroelastomer need not exceed 150 °C, since a higher temperature will not, after cooling; further reduce the outgassing rate of the fluoroelastomer. Fluoroelastomer O-rings have wider tolerances than those specified in BS1806.

They offer Very low outgassing rate (especially after baking) Chemical stability at high temperatures up to 200 °C, High resistance to oils and many chemical. A circumferential clamp and centering ring form the vacuum seal between the connecting flanges (please see top right figure - click to enlarge). The centering ring contains a rubber elastomer o-ring. The standard sizes for quick flange fittings are KF-10, KF-16, KF-25, KF-40, and KF-50 with flange sizes NW-10, NW-16, NW-25, NW-40, and NW-50, respectively. They are made of corrosive resistant stainless steel with Viton® O-Ring. Viton® is well known for its excellent resistance to heat (400°F/200°C) and to aggressive fuels and chemicals. Viton® is a registered trademark of DuPont Performance Elastomers.