1. WN welding neck flange;SO slip on ... 825 925 25-6mo hastelloy alloy B B-2 B-3 C-4 C-22 C-276 X C-2000 nimonic 80a 90 263 ... 309/S 316Ti etc ----------sunnyofsteel (at) gm ail c om 3. Face RF(raised face);FF(flat face ... ASME B16.47 series A, ASME B16.47 series B, MSS SP-44, API 605, API 590/ASME ... 6BX ,BS4504, ANSI B16.36 (orifice flange), DIN EN1092-1, BS3293 (26’’~48’’), API 605, API 6A, ASTM B564 ...