Centering Ring Assembly KF-25 with Screen, ISO-KF Flange Size NW-25, 4 micron Extreme Vacuum Protection

These KF-25 Centering Rings with screen vacuum fittings follow ISO-KF standards and have a flange size of NW-25. These centering rings with screen mesh are useful in many situations in which a vacuum system or instrument needs to be protected from contamination by particulate generated from outside the system or from within. They are commonly used to build foreline vacuum plumbing and process systems. They are often called quick flange fittings because they are quick to assemble. 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.