... 3.Standard:ANSI,DIN,EN1092-1 ASTM standard flange NameASTM standard flange Range½” (15 NB) to 64” (1200NB) in 150 LBS ... 10,16,25, 40,64,100,160 ETC. Available with NACE MR 01-75 material stainless steel , carbon ... long tapered hub and gentle transition of thickness in the region of the butt weld joining them ... of a butt welded joint between pipes, which, in practice, is the same as that of unwelded pipe ...