MSS SP-25-2008
1. SCOPE
1.1 This marking system applies to valves,fittings, flanges, and unions used in pipingconnections which include (but are not limited to)flanged, soldered, brazed, threaded, or weldedjoints.
1.2 These specified markings serve to identify themanufacturer, the rating designation, materials ofconstruction and special service limitations imposedby the manufacturer. They are used for productidentification and to assist in proper application.