STANDARD · ASME-B16-47-B
ASME B16.47 Series B Flange Dimensions
ASME B16.47-2025 · ASME B16.47 Series B
ASME B16.47 Series B is the former API 605 large-diameter flange standard, covering NPS 26 to NPS 60 in classes 150 to 900. Its outside diameters are smaller than Series A for the same size and class, which makes it attractive where space or weight is constrained.
Series B is dimensionally different from Series A and from B16.5. Always quote the series explicitly, and check the mating flange before ordering — a Series B flange will not bolt to a Series A flange of the same nominal size. B16.47 covers weld-neck and blind flanges only, 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 | 1022 | 154 | 762 | 901.7 | 20 × Ø66.7 | — | — | 991 kg | Spec sheet | |
| 28″DN700 | 1105 | 166.7 | 819 | 971.6 | 20 × Ø73 | — | — | 1253 kg | Spec sheet | |
| 30″DN750 | 1181 | 176 | 876 | 1035 | 20 × Ø79.4 | — | — | 1512 kg | Spec sheet | |
| 32″DN800 | 1238 | 185.7 | 927 | 1092.2 | 20 × Ø79.4 | — | — | 1753 kg | Spec sheet | |
| 34″DN850 | 1314 | 195 | 991 | 1155.7 | 20 × Ø85.7 | — | — | 2075 kg | Spec sheet | |
| 36″DN900 | 1346 | 201.6 | 1029 | 1200.2 | 24 × Ø79.4 | — | — | 2251 kg | Spec sheet | |
| 38″DN950 | 1460 | 215.9 | 1099 | 1289 | 20 × Ø92.1 | — | — | — | Spec sheet | |
| 40″DN1000 | 1511 | 223.8 | 1162 | 1339.8 | 24 × Ø92.1 | — | — | — | Spec sheet | |
| 42″DN1050 | 1562 | 231.6 | 1213 | 1390.6 | 24 × Ø92.1 | — | — | — | Spec sheet | |
| 44″DN1100 | 1648 | 242.9 | 1270 | 1463.5 | 24 × Ø98.4 | — | — | — | Spec sheet | |
| 46″DN1150 | 1734 | 255.6 | 1334 | 1536.7 | 24 × Ø104.8 | — | — | — | Spec sheet | |
| 48″DN1200 | 1784 | 263.5 | 1384 | 1587.5 | 24 × Ø104.8 | — | — | — | 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 B follows the former API 605 dimensions, with a smaller outside diameter and a different bolt pattern from Series A. Ratings are ASME classes 150, 300, 400, 600 and 900, with allowable pressure from the B16.47 tables.
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.