CANGZHOU YICHENG STEEL PIPE MANUFACTURE CO., LTD could provide you all forged steel flanges correspond to the requirements of the American Standards Association (ANSI Standard B16.5), and the two governing ASTM Specifications ASTM A181 for Class 150 (PN 20) and Class  300 (PN 50) pressure rating, and ASTM A105 for Class 400 (PN 64) through Class 2500 (PN 400) pressure ratings.