These LF100 TEES follow ISO-LF standards and have a flange size of NW-100. Large Flange fittings are commonly used to build foreline vacuum plumbing and process systems. The fittings are quick to assemble with a double claw clamp or a single claw clamp for tapped bored flanges and a centering ring forming the vacuum seal between the connecting flanges. The  centering ring contains a rubber/elastomeric o-ring. The standard sizes for Large Flanges are LF63, LF80, LF100, LF160, LF200, LF250, LF320, LF400, LF500, LF630. LF is an ISO standard but is often called LF, NW, or Large Flange. 

TEE NW-100 Vacuum Fittings, ISO-LF Large Flange Size NW-100, Stainless Steel

ISO-LF Flange Size: NW-100

Common Dimensions: A = 8.25" (216mm), B = 3.875" (108mm),