Steel plate flanges, Plate Flange, Slip-On Plate Flanges Production Range Size: 12″ (15 NB) to 48″ (1200NB), Custom Sizes, Pressure Ratings: Class 150, Class 300, Class 400, Class 600, Class 900, Class1500, Class 2500 | PN6, PN10, PN16, PN25, PN40, PN64 etc.