api5000Rev. 4. 0 2018. 07. 27 FLANGES - 87 API 6A FLANGES Size OD C E1 G K T J1 J4 R BC N H Ring Number BX 13 58˝ 675 6 14.3 408.00 457 112.8 481.0 23.9 16 590.60 16 45API flanges standard is American petroleum institute. API 6a6b6bx flanges dimensions are desned to handle hher rated pressure. We are an API 6a flanges manufacturer. Visit now!