These KF-16 vacuum fitting Red Silicone O-ring replacements are designed for ISO-KF standards with a size of NW-16. 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.

Silicone is a popular O Ring which is commonly red in color. The Red O Ring is made of elastomeric materials made from silicone, oxygen, hydrogen and carbon. Description: Excellent material for static service at extreme (hot or cold) temperatures. Outstanding flex and fatigue life. Very good for ozone and UV radiation service as well as for resistance to fungal and biological attack. Limitations: Avoid chlorinated solvents, aliphatic and aromatic hydrocarbons and petroleum oils. Silicones are generally very permeable to gases and have poor physical strength and abrasion resistance. Temperature Range: –51° to 232°C (–60° to 450°F) Typical Uses: LPCVD/Oxidation, Dry Etch, Resist Stripping.