MSS SP-44-2026

Abstract

This Standard Practice covers pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for steel pipeline flanges. The welding neck type flanges shall be forged steel, and the blind flanges may be made from either forged steel or from steel plate. Dimensional and tolerance requirements for NPS 10 and smaller are provided by reference to ASME B16.5. When such flanges are produced from materials meeting Table 2 requirements, and meet all other stipulations of this Standard Practice, then they shall be considered as complying therewith. This Standard Practice covers two Product Specification Levels (PSL). If no PSL is specified, material shall be supplied as PSL1 with the standard requirements as are contained in the body of this Standard Practice. If PSL2 is specified, the material shall meet the additional requirements specified in Supplementary Requirement SR-18 (see Annex E).