Weld neck flange (also known as a high-hub flange and tapered hub flange) is a type of flange. There are two designs. The regular type is used with pipes. The long type is unsuitable for pipes and is used in process plant.A weld neck flange consists of a circular fitting with a protruding rim around the circumference. Generally machined from a forging, these flanges are typically butt welded to a pipe. The rim has a series of drilled holes that permit the flange to be affixed to another flange with bolts.

ASME B16.47 Series B Welding Neck Flanges Class 150/300 LBS Dimensions

ASME B16.47 Series B Welding Neck Flanges Class 150/300 LBS Dimensions

 

ASME B16.47 Series B Welding Neck Flanges Class 150 LBS Dimensions
NPS A B I Holes C D F E G Weight
26″ 786 635 22.4 36 41.1 88.9 684.3 661.9 711.2 63.56
28″ 837 685.8 22.4 40 44.5 95.3 735.1 712.7 762 73.5
30″ 887 736.6 22.4 44 44.5 100.1 787.4 763.5 812.8 80.05
32″ 941 787.4 22.4 48 46 108 839.7 814.3 863.6 91.76
34″ 1005 838.2 25.4 40 49.3 110.2 892 865.1 920.8 110.27
36″ 1057 889 25.4 44 52.3 117.3 944.6 915.9 971.6 124.91
38″ 1124 939.8 28.4 40 53.8 124 997 968.2 1022.4 149.17
40″ 1175 990.6 28.4 44 55.6 128.5 1049.3 1019 1079.5 162.58
42″ 1226 1041.4 28.4 48 58.7 133.4 1101.9 1069.8 1130.3 179.18
44″ 1276 1092.2 31.8 52 60.5 136.7 1152.7 1120.6 1181.1 187.51
46″ 1341 1143 31.8 40 62 144.5 1205 1171.4 1234.9 223.84
48″ 1392 1193.8 31.8 44 65 149.4 1257.3 1222.2 1289.1 243.46
50″ 1443 1244.6 31.8 48 68.3 153.9 1308.1 1273 1339.9 263.22
52″ 1494 1295.4 31.8 52 69.9 157.2 1360.4 1323.8 1390.7 279.95
54″ 1549 1346.2 31.8 56 71.4 162.1 1412.7 1374.6 1441.5 303.62
56″ 1600 1397 31.8 60 73.2 166.6 1465.3 1425.4 1492.3 323.64
58″ 1675 1447.8 35.1 48 74.7 174.8 1516.1 1476.2 1543.1 383.77
60″ 1726 1498.6 35.1 52 76.2 179.3 1570 1527 1600.2 407.55

 

ASME B16.47 Series B Welding Neck Flanges Class 300 LBS Dimensions
NPS A B I Holes C D F E G Weight
26″ 867 635 35.1 32 88.9 144.5 701.5 665.2 736.6 189.56
28″ 921 685.8 35.1 36 88.9 149.4 755.7 716 787.4 207.56
30″ 991 736.6 38.1 36 93.7 158 812.8 768.4 844.6 254.27
32″ 1054 787.4 41.1 32 103.1 168.1 863.6 819.2 901.7 310.53
34″ 1108 838.2 41.1 36 103.1 173 917.4 870 952.5 333.98
36″ 1172 889 44.5 32 103.1 180.8 965.2 920.8 1009.7 374.99
38″ 1222 939.8 44.5 36 111.3 192 1016 971.6 1060.5 51.95
40″ 1273 990.6 44.5 40 115.8 198.4 1066.8 1022.4 1114.6 55.97
42″ 1334 1041.4 47.8 36 119.1 204.7 1117.6 1074.7 1168.4 508.46
44″ 1384 1092.2 47.8 40 127 214.4 1173.2 1125.5 1219.2 69.03
46″ 1461 1143 50.8 36 128.5 222.3 1128.9 1176.3 1270 12.74
48″ 1511 1193.8 50.8 40 128.5 223.8 1277.9 1227.1 1327.2 678.19
50″ 1562 1244.6 50.8 44 138.2 235 1330.5 1277.9 1378 90.66
52″ 1613 1295.4 50.8 48 142.7 242.8 1382.8 1328.7 1428.8 98.74
54″ 1673 1346.2 50.8 48 136.7 239.8 1435.1 1379.5 1479.6 829.33
56″ 1765 1397 60.5 36 153.9 268.2 1493.8 1422.4 1536.7 122.93
58″ 1827 1447.8 60.5 40 153.9 274.6 1547.9 1481.1 1593.9 147.04
60″ 1878 1498.6 60.5 40 150.9 271.5 1598.7 1531.9 1651 1201.14
ASME B16.47 Series B Welding Neck Flanges Class 400-900 LBS Dimensions

ASME B16.47 Series B Welding Neck Flanges Class 400-900 LBS Dimensions

 

ASME B16.47 Series B Welding Neck Flanges Class 400 LBS Dimensions
NPS A B I Holes C D F E G Weight
26″ 850.9 635 38.1 28 88.9 149.35 688.85 660.4 711.2 165.95
28″ 914.4 685.8 41.15 24 95.25 158.9 739.65 711.2 762 204.49
30″ 971.55 736.6 41.15 28 101.6 169.93 793.75 762 819.15 239.2
32″ 1035.1 787.4 44.45 28 107.95 179.32 844.55 812.8 873.25 283.06
34″ 1085.9 838.2 44.45 32 111.25 187.45 898.65 863 927.1 307.92
36″ 1155.7 889 47.75 28 119.13 200.15 952.5 914.4 980.95 381.98

 

ASME B16.47 Series B Welding Neck Flanges Class 600 LBS Dimensions
NPS A B I Holes C D F E G Weight
26″ 889 635 44.45 28 111.25 180.85 698.5 660.4 726.95 244.55
28″ 952.5 685.8 47.75 28 115.82 190.5 752.35 711.2 784.35 287.49
30″ 1022.4 736.6 50.8 28 125.48 204.72 806.45 762 841.25 358.02
32″ 1085.9 787.4 53.85 28 130.05 215.9 860.55 812.8 895.35 414.01
34″ 1162.1 838.2 60.45 24 141.22 233.43 914.4 863.6 952.5 523.71
36″ 1212.9 889 60.45 28 146.05 242.82 968.25 914.4 1009.7 564.36

 

ASME B16.47 Series B Welding Neck Flanges Class 900 LBS Dimensions
NPS A B I Holes C D F E G Weight
26″ 1022.4 635 66.55 20 134.87 258.83 742.95 660.4 762 513.64
28″ 1104.9 685.8 73.15 20 147.57 276.35 797.05 711.2 819.15 646.22
30″ 1181.1 736.6 79.25 20 155.45 289.05 850.9 762 876.3 765.72
32″ 1238.3 787.4 79.25 20 160.27 303.28 908.05 812.8 927.1 863.06
34″ 1314.5 838.2 85.85 20 171.45 319.02 962.15 863.6 990.6 1023.53
36″ 1346.2 889 79.25 24 172.97 325.37 1016 914.4 1028.7 1038.21