The Welding neck flanges is normally referred to as the high hub flange. It is designed to transfer stresses to the pipe, thereby reducing high stress concentrations at the base of the flange.
The welding neck flange is the best designed butt-welded flange of those currently available because of its inherent structural value. It is expensive because of the design.
The welding neck flange is the best designed butt-welded flange of those currently available because of its inherent structural value. It is expensive because of the design.
| Norminal Pipe Size | O.D.of Flange, O | Min.Thick-ness of WN Flange, tf | Lenth Through Hub, Y | Diam. of Hub, X | Hub Diam. Top, A | Raised Fase Diam., R | Bore (XS) | Diam of Bolt Circle | No.of Bolt Holes | Diam.of Bolt Hole | Min.Fillet Radius, r1 | Approxi-mate Weight kgs |
| 26 | 1085 | 139.7 | 286 | 775 | 660.4 | 749 | 635.0 | 952.5 | 20 | 73.0 | 11 | 683.01 |
| 28 | 1170 | 142.9 | 298 | 832 | 711.2 | 800 | 685.8 | 1022.4 | 20 | 79.4 | 13 | 808.16 |
| 30 | 1230 | 149.3 | 311 | 889 | 762.0 | 857 | 736.6 | 1085.8 | 20 | 79.4 | 13 | 924.60 |
| 32 | 1315 | 158.8 | 330 | 946 | 812.8 | 914 | 787.4 | 1155.7 | 20 | 85.7 | 13 | 1114.09 |
| 34 | 1395 | 165.1 | 349 | 1006 | 863.6 | 965 | 838.2 | 1225.6 | 20 | 92.1 | 14 | 1298.15 |
| 36 | 1460 | 171.5 | 362 | 1064 | 914.4 | 1022 | 889.0 | 1289.0 | 20 | 92.1 | 14 | 1472.04 |
| 38 | 1460 | 190.5 | 352 | 1073 | 965.2 | 1099 | 939.8 | 1289.0 | 20 | 92.1 | 19 | 1436.84 |
| 40 | 1510 | 196.9 | 364 | 1127 | 1016.0 | 1162 | 990.6 | 1339.8 | 24 | 92.1 | 21 | 1518.64 |
| 42 | 1560 | 206.4 | 371 | 1176 | 1066.0 | 1213 | 1040.6 | 1390.6 | 24 | 92.1 | 21 | 1654.33 |
| 44 | 1650 | 214.4 | 391 | 1235 | 1117.6 | 1270 | 1092.2 | 1463.7 | 24 | 98.4 | 22 | 1941.88 |
| 46 | 1735 | 225.5 | 411 | 1292 | 1168.4 | 1334 | 1143.0 | 1536.7 | 24 | 104.8 | 22 | 2261.24 |
| 48 | 1785 | 233.4 | 419 | 1343 | 1219.2 | 1384 | 1193.8 | 1587.5 | 24 | 104.8 | 24 | 2425.26 |