These half nipple bolted weld on stubs follow International Standards Organization (ISO) standards and have a flange size of NW-100. ISO flanged vacuum fittings are commonly used to build process vacuum plumbing and systems for industrial applications. These fittings use 8 nuts and bolts to attach to other vacuum hardware. The centering ring is also needed and contains a rubber/elastomeric o-ring. The ISO standard sizes for large flanges are NW-63, NW-80, NW-100, NW-160, NW-200, NW-250, NW-320, NW-400, NW-500, NW-630. These vacuum flanges are made of stainless steel.

Nipple Half Weld Bolted Stub, NW-100 Vacuum Fittings, ISO-LF Large Flange Size NW-100, 8 bolt, Stainless Steel 

ISO-LF Flange Size: NW-100

Common Dimensions: A = 6 1/2" (165mm), B = 4" (102mm), C = 3.15/16" (100mm)