Z245.12-01

(It includes Update #1 and #2)

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, inclusive.  The standard grades are shown in Table 1.

1.2.3  Nominal Pressure Class
This Standard covers flanges having cold working-pressure ratings designated by nominal pressure classes from PN 20 to PN 420, inclusive.  The standard nominal pressure classes are shown in Table 2.  (ASME class designations are shown in Appendix B.)

1.2.4  Category
This Standard covers flanges in the following categories:

Category I - flanges without requirements for proven notch-toughness properties; and
Category II - flanges with requirements for proven notch-toughness properties.

1.3  Assemblies
This Standard does not cover assemblies.*
*An assembly means a grouping of fittings or flanges, or both, joined by one or more circumferential welds.