Published October 1, 2021

MSS revises standards SP-6 and SP-129

The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry has revised and published standards SP-6 and SP-129, announced in two press releases on Sept. 30.


The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry has revised and published standards SP-6 and SP-129, announced in two press releases on Sept. 30.

The first is the seminal SP-6-2021, Standard Finishes for Contact Faces of Pipe Flanges and Connecting-End Flanges of Valves and Fittings. For more than 91 years, SP-6 for standard contact face finishes has served as an industry norm and is referenced in many other technical documents. As one of MSS’s first standards developed, it continues to define a standardized finish for gasket contact faces of pipe flanges and connecting-end flanges of valves and fittings. This Standard Practice is also intended for applications to products for which ASME B16 Standards do not contain complete facing finish requirements or for which there are no such standards.

SP-6 continues to be maintained under the consensus of MSS Technical Committee 102, Iron Flanges & Flanged Fittings (primary), Technical Committee 110, Steel Flanges & Flanged Fittings (secondary), and Technical Committee 201, Non-Ferrous Fittings and Flanges (secondary).

The second revised standard is SP-129-2021, Copper-Nickel Fittings. SP-129 has served the industry for more than 18 years—establishing requirements for copper-nickel fittings from Nominal Pipe Size (NPS) 1/4 through NPS 12 (or as noted), for use with pipe manufactured to one of the following standards: MIL-T-16420K, ASTM B466/B466M, ASTM B467. SP-129 continues to be maintained under the consensus of MSS Technical Committee 201, Non-Ferrous Fittings and Flanges.

The revised Standard Practices are now available from authorized U.S. and global distributors. They have been published in an electronic version (PDF) and in book format.

VMA Valve Forum 2026 banner - April 13-15 The Woodlands Texas annual event
Valve Careers banner - connect top talent with top positions at valvecareers.vma.org
VMA Valve Industry Buyers Guide banner - find U.S. and Canadian valve companies for your project
Baker Hughes Optimize Service banner - proactively manage valve maintenance with VLM Cloud
Baker Hughes Optimize Service ad - track valve maintenance and identify spare parts with VLM Cloud