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.