Connection. It is what human beings crave. For pipes, it is more than a desire. It is essential. Without connectors, pipes would struggle to transfer substances. Valves, fittings, flanges, and unions are all devices that provide these significant connections. Within the pages of ANSI/MSS SP-25-2018: Standard Marking System for Valves, Fittings, Flanges, and Unions, the Standard Marking System for these apparatuses can be found. This document revises the 2013 edition of the same American National Standard.
The scope of ANSI/MSS SP-25-2018 covers the marking systems for parts essential to pipe connection. Valves, flanges, fittings, and unions employed in piping connections that incorporate soldered, flanged, brazed, threaded, or welding joints fall under the scope of the standard. The ability to identify the manufacturer, the rating designation, materials of construction, and special service limitations levied by the manufacturer are helpful in projects pertaining to piping. The marking system in ANSI/MSS SP 25-2018 was created to manage this need. The system is also important for the identification of products and the correct use of the devices. It is important to note that valves, fittings, flanges, and unions that have been remanufactured and refurbished are not covered under the standard.
The beginnings of ANSI/MSS SP-25 started in 1934. Developed by the Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry, earlier editions of this standard helped establish the basics of the Standard Marking System. However, the document was thought to need more detail and has evolved into what it is today. The latest edition of the standard has made changes from the 2013 one. They are:
- Products with rating designations that are constant throughout a certain temperature range have a new section.
- Guidelines involving the marking of a manufacture’s name, trademark, logo, or symbol have been revised.
- Two material designation subsections that involve standard reference for marking nameplates and bodies have been revised.
- Tables 1 and 2 that refer to examples of common symbols for metallic/non-metallic materials were updated.
- Terminology has been updated.
- For specific non-ferrous flanges, flanged fittings, and flanged unions, extra material designations have been included.
- Annex B was updated to include modified and new examples.
- References in Annex C were updated.
ANSI/MSS SP-25-2018: Standard Marking System for Valves, Fittings, Flanges, and Unions is available on the ANSI Webstore.