# ASME B16.47-2025 marking requirements (Section 4)
# Standard: ASME B16.47-2025
# Verified: 2026-11-04
# Source: ASME B16.47-2025, Section 4, Marking, paras. 4.1-4.2.9, pp. 3-4 (PDF pp. 18-19); ASME B16.47-2025, Table 1 and para. 4.2.8 (multiple material marking), pp. 11 and 4 (PDF pp. 26 and 19); ASME B16.47-2025, footnote to para. 4.2.2 on ASME BPVC Section II specifications, p. 3 (PDF p. 18); ASME B16.47-2025, para. 4.1 reference to MSS SP-25, p. 3 (PDF p. 18)
# Reference data only. The purchased standard edition governs.

# Section 4, para. 4.2 (pp. 3-4) — identification markings required by B16.47-2025
Marking element,Requirement,Clause
Manufacturer,Manufacturer's name or trademark applied to the flange.,4.2.1
Material — castings,"ASTM specification, grade identification symbol, and the melt number or melt identification.",4.2.2(a)
Material — forgings and plate,ASTM specification number and grade identification symbol.,4.2.2(b)
Trade designation (optional),"The manufacturer may add a trade name for the grade, provided the symbols cannot be confused.",4.2.2(c)
Pressure class,"The class number: 75, 150, 300, 400, 600 or 900.",4.2.3
Standard conformance,"The designation B16 or B16.47, preferably adjacent to the class designation. The prefix 'ASME' is optional.",4.2.4
Size,The NPS identification number.,4.2.6
Ring-joint flange,The letter R and the corresponding ring-groove number on the edge (periphery) of the flange.,4.2.7
Temperature (optional),"Not required; if marked, the temperature must be shown with its corresponding tabulated pressure rating.",4.2.5
Multiple material grades (optional),"If the material meets more than one specification or grade, more than one may be marked, following ASME BPVC Section II, Part D, Appendix 7.",4.2.8
Case number,"When the flange meets an ASME Case, the marking includes 'Case ##'.",4.2.9