1. Scope
1.1 General This Standard covers wrought steel flanges primarily intended for use in oil or gas pipeline systems.
1.2 Size, Grade, Nominal Pressure Class, and Category 1.2.1 Size This Standard covers flanges in sizes from NPS 1/2 to NPS 60, inclusive. (Refer to Appendix A, Table A1.) 1.2.2 Grade This Standard covers flanges from Grade 248 to Grade 483, in clusive. The standard grades are shown in Table
1. 1.2.3 Nominal Pressure Class This Standard covers flanges having cold working-pressure r atings designated by nominal pressure classes from PN 20 to PN 420, inclusive. The standard nominal pressure classes are shown in Table 2. (ANSI class designations are shown in Appendix B.) 1.2.4 Category This Standard covers flanges in the following categories: (a) Category I - flanges without requirements for proven notch- toughness properties; and (b) Category II - flan