ASME B16.47 governs flanges above NPS 24, from NPS 26 to NPS 60. It exists in two series — Series A and Series B — with different outside diameters and bolt circles. A Series A flange will not bolt to a Series B flange of the same size, so the series has to be stated on every enquiry. The table below gives Series A, Class 150 dimensions in millimetres.
ASME B16.47 Series A, Class 150 — dimensions (NPS 26–48)
| NPS | DN | Flange OD (mm) | Min. thickness (mm) | Bolt circle / PCD (mm) | Bolts | Bolt size | Hole dia (mm) | Raised face dia (mm) |
|---|---|---|---|---|---|---|---|---|
| 26 | 650 | 870.0 | 46.0 | 806.5 | 24 | M33 | 35.1 | 749.3 |
| 28 | 700 | 927.1 | 49.3 | 863.6 | 28 | M33 | 35.1 | 800.1 |
| 30 | 750 | 984.3 | 50.8 | 914.4 | 28 | M33 | 35.1 | 857.3 |
| 32 | 800 | 1060.5 | 53.8 | 977.9 | 28 | M39 | 41.3 | 914.4 |
| 34 | 850 | 1111.3 | 53.8 | 1028.7 | 32 | M39 | 41.3 | 965.2 |
| 36 | 900 | 1168.4 | 57.2 | 1085.9 | 32 | M39 | 41.3 | 1022.4 |
| 38 | 950 | 1238.3 | 57.2 | 1149.4 | 32 | M39 | 41.3 | 1073.2 |
| 40 | 1000 | 1289.1 | 60.5 | 1200.2 | 36 | M39 | 41.3 | 1124.0 |
| 42 | 1050 | 1339.9 | 60.5 | 1250.9 | 36 | M39 | 41.3 | 1193.9 |
| 44 | 1100 | 1416.1 | 63.5 | 1314.5 | 36 | M42 | 44.5 | 1244.6 |
| 46 | 1150 | 1466.9 | 63.5 | 1365.3 | 40 | M42 | 44.5 | 1295.4 |
| 48 | 1200 | 1536.7 | 66.5 | 1435.1 | 40 | M42 | 44.5 | 1358.9 |
Data to ASME B16.47 Series A. Thickness includes the 1.6 mm raised face. Blind flanges share the outside diameter, bolt circle and bolting, with a thickness calculated for the design condition — confirm against the project specification before fabrication.
Series A or Series B?
| Point | Series A | Series B (API 605) |
|---|---|---|
| Outside diameter | Larger for a given size | Smaller, closer to the pipe OD |
| Bolt circle and bolting | More and larger bolts | Fewer bolts than Series A |
| Interchangeability | None — Series A and Series B do not bolt together at the same size | |
| How the series is decided | By the existing flange it has to mate with, or by the project specification | |
What to state on a B16.47 enquiry
Nominal size, series (A or B), pressure class, flange type, facing and material. For a weld neck, add the pipe wall thickness, because the bore follows the pipe. For a blind, state the design pressure and temperature so the thickness can be confirmed.
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Related pages
Large diameter flanges · ASME B16.5 dimensions · All flange types
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