Manufacturers Standardization Society of the Valve and Fittings Industry (MSS)
MSS (Manufacturers Standardization Society) plays a key role in developing standards that ensure the quality, safety, and performance of valves, fittings, flanges, and piping systems used across various industries.
Nimonik provides seamless access to official MSS standards in both PDF and print formats through our Standards Store, as well as through a subscription service available to your entire team. We take pride in our strong relationships with standards development organizations (SDOs) and the customers we serve.
Popular MSS Standards
| Standard Code | Title | Format Available |
|---|---|---|
| MSS SP-87 | Factory-Made Butt-Welding Fittings for Class I Nuclear Piping Applications | PDF, Print |
| MSS SP-91 | Guidelines for Manual Operation of Valves | PDF, Print |
| MSS SP-110 | Ball Valves Threaded, Socket-Welding, Solder Joint, Grooved and Flared Ends | PDF, Print |
| MSS SP-72 | Ball Valves with Flanged or Butt-Welding Ends for General Service | PDF, Print |
| MSS SP-55 | Quality Standard for Steel Castings for Valves, Flanges, Fittings, and Other Piping Components–Visual Method for Evaluation of Surface Irregularities | PDF, Print |
What Are MSS Standards?
The Manufacturers Standardization Society of the Valve and Fittings Industry (MSS) is a leading industry association that develops and maintains technical standards for valves, fittings, flanges, pipe hangers, and related components. Since its founding in 1924, MSS has been committed to creating standardized specifications that improve product quality, compatibility, and safety in various industries, including oil and gas, water treatment, and power generation.
MSS standards cover essential areas such as valve design, materials, testing, and performance, ensuring products meet the rigorous demands of industrial applications. By following MSS guidelines, manufacturers and engineers can enhance reliability, safety, and efficiency in piping systems while reducing maintenance costs and downtime.
One of the core goals of MSS is to promote the global harmonization of standards, reducing technical barriers to trade and simplifying the integration of valves and fittings across different regions and industries. Compliance with MSS standards allows manufacturers to meet international expectations and maintain competitiveness in a global market.
