STANDARD · ASME-B16-47-A
ASME B16.47 Series A Flange Dimensions
ASME B16.47-2025 · ASME B16.47 Series A
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.
DIMENSIONS
Dimension tables
One row per specification. Open a size for the drawing, pressure ratings and printable A4 sheet.
Blind: A solid disc bolted over a line end or vessel opening for isolation, testing and future tie-ins. 84 specifications.
| Size | Rating | Outside Ø D | Thickness C | Raised face D2 | Bolt circle K | Bolting | Hub A | Length H | Weight | |
|---|---|---|---|---|---|---|---|---|---|---|
| 26″DN650 | 1016 | 125.4 | 749 | 914.4 | 28 × Ø50.8 | — | — | 798 kg | Spec sheet | |
| 28″DN700 | 1073 | 131.8 | 800 | 965.2 | 28 × Ø54 | — | — | 935 kg | Spec sheet | |
| 30″DN750 | 1130 | 139.7 | 857 | 1022.4 | 28 × Ø54 | — | — | 1099 kg | Spec sheet | |
| 32″DN800 | 1194 | 147.6 | 914 | 1079.5 | 28 × Ø60.3 | — | — | 1296 kg | Spec sheet | |
| 34″DN850 | 1245 | 154 | 965 | 1130.3 | 28 × Ø60.3 | — | — | 1468 kg | Spec sheet | |
| 36″DN900 | 1314 | 162.1 | 1022 | 1193.8 | 28 × Ø66.7 | — | — | 1724 kg | Spec sheet | |
| 38″DN950 | 1270 | 155.4 | 1054 | 1162 | 28 × Ø60.3 | — | — | 1544 kg | Spec sheet | |
| 40″DN1000 | 1321 | 162.1 | 1111 | 1212.8 | 32 × Ø60.3 | — | — | 1741 kg | Spec sheet | |
| 42″DN1050 | 1403 | 171.5 | 1168 | 1282.7 | 28 × Ø66.7 | — | — | 2080 kg | Spec sheet | |
| 44″DN1100 | 1454 | 177.8 | 1226 | 1333.5 | 32 × Ø66.7 | — | — | 2316 kg | Spec sheet | |
| 46″DN1150 | 1511 | 185.7 | 1276 | 1390.6 | 32 × Ø66.7 | — | — | 2612 kg | Spec sheet | |
| 48″DN1200 | 1594 | 195.3 | 1334 | 1460.5 | 32 × Ø73 | — | — | 3056 kg | Spec sheet | |
| 50″DN1250 | 1670 | 203.2 | 1384 | 1524 | 28 × Ø79.4 | — | — | 3490 kg | Spec sheet | |
| 52″DN1300 | 1721 | 209.6 | 1435 | 1574.8 | 32 × Ø79.4 | — | — | 3822 kg | Spec sheet | |
| 54″DN1350 | 1778 | 217.5 | 1492 | 1632 | 32 × Ø79.4 | — | — | 4233 kg | Spec sheet | |
| 56″DN1400 | 1854 | 225.6 | 1543 | 1695.4 | 32 × Ø85.7 | — | — | 4776 kg | Spec sheet | |
| 58″DN1450 | 1905 | 231.6 | 1600 | 1746.2 | 32 × Ø85.7 | — | — | 5177 kg | Spec sheet | |
| 60″DN1500 | 1994 | 242.9 | 1657 | 1822.4 | 28 × Ø92.1 | — | — | 5946 kg | Spec sheet |
REFERENCE
Pressure ratings, materials and tolerances
Transcribed from ASME B16.47-2025 with table and page references.
ASME B16.47-2025 pressure–temperature ratings (Group 1.1)
Table 3 (SI, bar) and Table 3C (U.S. customary, psig) of ASME B16.47-2025 give the maximum working pressure o…
Open reference Material groupsASME B16.47-2025 material groups (Table 1)
ASME B16.47-2025 sorts every permitted flange material into a numbered group, and the group number — not the …
Open reference TolerancesASME B16.47-2025 flange tolerances (Section 7)
Section 7 of ASME B16.47-2025 sets the permissible manufacturing deviations for large-diameter flanges: raise…
Open reference MarkingASME B16.47-2025 marking requirements (Section 4)
Section 4 of ASME B16.47-2025 defines the identification markings that must appear on every large-diameter fl…
Open reference Edition changesASME B16.47-2025 changes and record numbers
ASME B16.47-2025 was approved by the American National Standards Institute on 4 March 2025 and issued on 30 M…
Open referenceHow 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.