There are 13 or 19mm short weld stubs with a NW10 to NW50 size ISO-KF vacuum flange. They are used to with butt weld fitting to get ISO-KF flange accessories, such as elbow, tee, reducer etc to make stainless steel tubing.
13 or 19 mm butt-weld stub
304 Stainless Steel construction or aluminum
NW10 to NW50 flange sizes
The International Standards Organization (ISO) has defined the interface dimensions, allowing the interchanging of components that conform to the ISO-KF standard’s dimensions. The ISO-KF system is a modular, building block method of creating a vacuum piping system. There are several advantages in the use of ISO components. Since component dimensions are standardized, elbows, tees, crosses or valves for a given size may be interchanged. By using ISO components, system assembly is quick and cost effective. The Series 31 component line also includes a few components in NW 80 (3'') and NW 100 (4'') sizes. There is no international standard for these sizes in the KF style.