ASME B16.47 Series B class 75 flange: dimensions and bolt pattern
Large-diameter flanges, NPS 26 to 60, weld neck (WN) and blind. Series B (formerly API 605) has more compact and lighter flanges, with more, smaller-diameter bolts. Common in heat exchangers and equipment.
Dimensions and bolt pattern
| NPS | DN | O | tf WN | tf blind | X | Ah | Y | W | Holes | Hole Ø | Bolt | WN weight* | Blind weight* |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 26" | 650 | 762.0 | 31.8 | 31.8 | 676.1 | 661.9 | 57.1 | 723.9 | 36 | 19.1 | ⅝" | 36 | 111 |
| 28" | 700 | 812.8 | 31.8 | 31.8 | 726.9 | 712.7 | 60.5 | 774.7 | 40 | 19.1 | ⅝" | 39 | 127 |
| 30" | 750 | 863.6 | 31.8 | 31.8 | 777.7 | 763.5 | 63.5 | 825.5 | 44 | 19.1 | ⅝" | 42 | 143 |
| 32" | 800 | 914.4 | 33.5 | 33.8 | 828.5 | 814.3 | 68.3 | 876.3 | 48 | 19.1 | ⅝" | 48 | 171 |
| 34" | 850 | 965.2 | 33.5 | 36.6 | 879.3 | 865.1 | 71.6 | 927.1 | 52 | 19.1 | ⅝" | 51 | 206 |
| 36" | 900 | 1033.5 | 35.1 | 40.9 | 935.0 | 915.9 | 84.3 | 992.1 | 40 | 22.2 | ¾" | 69 | 264 |
| 38" | 950 | 1084.3 | 36.6 | 42.9 | 985.8 | 965.2 | 87.4 | 1042.9 | 40 | 22.2 | ¾" | 77 | 306 |
| 40" | 1000 | 1135.1 | 36.6 | 42.9 | 1036.6 | 1017.5 | 90.7 | 1093.7 | 44 | 22.2 | ¾" | 80 | 335 |
| 42" | 1050 | 1185.9 | 38.1 | 46.2 | 1087.4 | 1068.3 | 93.7 | 1144.5 | 48 | 22.2 | ¾" | 87 | 394 |
| 44" | 1100 | 1251.0 | 41.4 | 47.8 | 1139.2 | 1119.1 | 103.4 | 1203.5 | 36 | 25.4 | ⅞" | 109 | 454 |
| 46" | 1150 | 1301.8 | 42.9 | 49.3 | 1190.8 | 1169.9 | 106.4 | 1254.3 | 40 | 25.4 | ⅞" | 118 | 507 |
| 48" | 1200 | 1352.6 | 44.5 | 52.6 | 1240.3 | 1220.7 | 109.7 | 1305.1 | 44 | 25.4 | ⅞" | 126 | 584 |
| 50" | 1250 | 1403.4 | 46.2 | 54.1 | 1293.9 | 1271.5 | 114.3 | 1355.9 | 44 | 25.4 | ⅞" | 138 | 647 |
| 52" | 1300 | 1457.5 | 46.2 | 55.6 | 1344.7 | 1322.3 | 119.1 | 1409.7 | 48 | 25.4 | ⅞" | 148 | 718 |
| 54" | 1350 | 1508.3 | 47.8 | 58.9 | 1397.0 | 1373.1 | 124.0 | 1460.5 | 48 | 25.4 | ⅞" | 161 | 815 |
| 56" | 1400 | 1574.8 | 49.3 | 60.5 | 1450.8 | 1423.9 | 133.3 | 1521.0 | 40 | 28.6 | 1" | 192 | 913 |
| 58" | 1450 | 1625.6 | 50.8 | 62.0 | 1501.6 | 1474.7 | 136.7 | 1571.8 | 44 | 28.6 | 1" | 203 | 996 |
| 60" | 1500 | 1676.4 | 54.1 | 65.3 | 1552.4 | 1525.5 | 143.0 | 1609.9 | 44 | 28.6 | 1" | 223 | 1117 |
O = outside diameter · tf = thickness (without raised face) · X = hub at base · Ah = diameter at bevel · Y = overall length of the WN · W = bolt circle. Weight estimated in carbon steel with STD wall bore; stainless ≈ +1 %, nickel alloys +7 % to +13 %.
Frequently asked questions
What is the difference between Series A and Series B of ASME B16.47?
Both cover NPS 26 to 60, but they are not interchangeable: outside diameter, bolt circle and number of bolts are different. Series A is more robust (formerly MSS SP-44); Series B is more compact (formerly API 605). Check the series on the drawing before buying.
When to use ASME B16.47 instead of B16.5?
ASME B16.5 goes up to NPS 24. From NPS 26 to 60, ASME B16.47 applies, in Series A or B.
