The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry recently announced that ANSI/MSS SP-55-2025, Quality Standard for Iron and Steel Castings for Valves, Flanges, Fittings, and Other Piping Components | Visual Method for Evaluation of Surface Irregularities has been approved by the American National Standards Institute (ANSI) as a revised American National Standard (ANS) and published by MSS.

When introduced, the scope of SP-55 was for steel castings, and it was adopted as a requirement into ASTM and ASME standards, according to MSS Board Member David Woollums. For the 2025 edition, the scope of the standard was increased to include iron castings.  Many of the members of MSS also produce valves, fittings, and other pressure containing piping components made from iron and ductile iron castings. 

“The technical committee responsible for SP-55 noticed that the iron casting industry did not have a similar standard that harmonized what is acceptable and not acceptable for surface defects,” Woollums said. “Discussions with casting experts from MSS and iron foundries confirmed that SP-55 can also be applied to iron castings, ensuring common acceptable criteria between foundries and customers.”

For more information or to purchase actual-size, laminated defect photos, visit www.msshq.org.