1. Scope
1.1 General This Standard covers wrought steel buttwelding fittings, including extruded headers and factory-produced bends, primarily intended for use in oil or gas pipeline systems.
1.2 Size, Grade, and Category 1.2.1 Size This Standard covers fittings in sizes from NPS 1/2 to NPS 60, inclusive. (Refer to Appendix A, Table A1.) 1.2.2 Grade This Standard covers fittings from Grade 207 to Grade 550, inclusive. The standard grades are shown in Table
1. 1.2.3 Category This Standard covers fittings in the following categories: (a) Category I - fittings without requirements for proven notch- toughness properties; and (b) Category II - fittings 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.