ASME B16.5 Standard-Pipe Flanges and Flanged Fittings(NPS 1/2 Through NPS 24 Metric/Inch Standard) Marking

ASME B16.5 Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and methods of designating openings for pipe flanges and flanged fittings.

Haihao Group forged flanges engineering department,design,produce,inspect and supply our forged flanges according to the ASME B16.5 standard.

ASME B16.5 Standard – Pipe Flanges and Flanged Fittings(NPS 1/2 Through NPS 24 Metric/Inch Standard)

• 1. SCOPE
• 2. PRESSURE-TEMPERATURE RATINGS
• 3. COMPONENT SIZE
• 4. MARKING
• 5. MATERIALS
• 6. DIMENSIONS
• 7. TOLERANCES
• 8. PRESSURE TESTING

ANSI ASME B16.5 class 150 threaded flange

4 MARKING

4.1 General

Except as modified herein,flanges and flanged fittings shall be marked as required in MSS SP-25,except as noted in para. 4.2.

4.2 Identification Markings

4.2.1 Name. The manufacture’s name or trademark shall be applied.

4.2.2 Material. Material shall be identified in the following way:

(a) Cast flanges and flanged fittings shall be marked with the ASTM specification,² grade identification symbol(letters and numbers),and the melt number or melt identification.

(b) Plate flanges,forged flanges,and flanged fittings shall be marked with the ASTM specification number and grade identification symbol.²

(c) A manufacturer may supplement these mandatory material indications with his trade designation for the material grade,but confusion of symbols shall be avoided.

(d) For flanges and flanged fittings manufactured from material that meets the requirements of more than one specification or grade of a specification listed in Table 1.1-1,see para. 4.2.8.

4.2.3 Rating Designation. The flange or flanged fitting shall be marked with the number that corresponds to its pressure rating class designation (i.e.,150,300,400,600,900,1500 or 2500).

4.2.4 Conformance. The designation B16 or B16.5 shall be applied to the flange or flanged fitting,preferably located adjacent to the class designation,to indicate conformance to this Standard.The use of the prefix ASME is optional.

4.2.5 Temperature. Temperature marking are not required on flanges or flanged fittings;however,if marked,the temperature shall be shown with its corre-sponding tabulated pressure rating for the material.

4.2.6 Size. The NPS designation shall be marked on flanges and flanged fittings.Reducing flanges and reducing flanged fittings shall be marked with the applicable NPS designations as required by paras.3.2 and 3.3.

4.2.7 Ring Joint Flanges. The edge (periphery) of each ring joint flange shall be marked with the letter R and the corresponding ring groove number.

4.2.8 Multiple Material Marking. Material for components that meet the requirements for more than one specification or grade of a specification listed in Table 1.1-1 may,at the manufacturer’s option,be marked with more than one of the applicable specification or grade symbols.These identification markings shall be placed so as to avoid confusion in identification.The multiple marking shall be in accordance with the guidelines set out in ASEM Boiler and Pressure Vessel Code,Section Ⅱ，Part D,Mandatory Appendix 7.

² An ASME Boiler and Pressure Vessel Code,Spection Ⅱspecification number may be substituted for an ASTM specification number provided  the requirements of the ASME specification are identical to or more stringent than the ASTM specification for the Grade,Class,or Type of material.

Related:

ASME B16.5 Welding Neck Flange Dimensions (150lb-2500lb)
ASME B16.5 Slip On Flange Dimensions (150lb-1500lb)
ASME B16.5 Blind Flange Dimensions (150lb-2500lb)
ASME B16.5 Socket Welding Flange Dimensions (150lb-1500lb)
ASME B16.5 Lap Joint Flange Dimensions (150lb-2500lb)
ASME B16.5 Threaded Flange Dimensions (150lb-2500lb)