STANDARD · ASME-B16-47-A

ASME B16.47 Series A Flange Dimensions

ASME B16.47-2025 · ASME B16.47 Series A

ASME B16.47-2025North America, Middle Eastpressure class

ASME B16.47 covers large-diameter flanges from NPS 26 to NPS 60. Series A preserves the former MSS SP-44 dimensions and is the series most often specified for large-bore oil and gas, water and process piping.

Series A and Series B use different outside diameters and bolt patterns for the same size and class, so the series must be stated on the purchase order. A Series A flange will not bolt to a Series B flange, and neither will bolt to an ASME B16.5 flange of the same nominal size. B16.47 covers weld-neck and blind flanges only — slip-on flanges above NPS 24 are made to drawing — and Class 900 is published up to NPS 48.

Base materialASTM A105
Size notationNPS (inch)
Material options5 groups
Reference data5 topics

DIMENSIONS

Dimension tables

One row per specification. Open a size for the drawing, pressure ratings and printable A4 sheet.

Weld Neck: Butt-welded to the pipe with a tapered hub; used for high pressure, high temperature and cyclic service. 84 specifications.

84 specifications
SizeRatingOutside Ø DThickness CRaised face D2Bolt circle KBoltingHub ALength HWeight
60″DN1500 Class 150 1854130.316761759 52 × Ø47.61559238 928 kg Spec sheet
60″DN1500 Class 300 1810162.116261701.8 32 × Ø60.31565272 1120 kg Spec sheet
60″DN1500 Class 400 1886185.716351752.6 32 × Ø731584319 1733 kg Spec sheet
60″DN1500 Class 600 1994233.416571822.4 28 × Ø92.11610389 2268 kg Spec sheet

How to read the pressure class

Series A follows the former MSS SP-44 dimensions. Ratings are ASME classes 150, 300, 400, 600 and 900, with allowable pressures read from the B16.47 pressure–temperature tables for the material group and design temperature.

Edition and verification

Dimension values on this page have been checked against ASME B16.47-2025 (SI tables, cross-checked against the U.S. Customary tables). The 2025 edition prints exact metric equivalents of the inch dimensions rather than the old 5 mm-rounded values (for example 36.50 in is printed as 927 mm, not 925 mm), and defines flange thickness as excluding the raised face. Both corrections are reflected here; Series B NPS 38 and above follows Series A per the standard’s General Note (h).

Data imported 2026-11-05 08:05.