Export Office: 21Floor, No.5 Nanhai Zhi Road,Qingdao, Shandong ,China
Work Shop: Beian Industrial zone, Qingdao,Shandong,China
+86 532 88256399
Martin
The size of the welding neck flange hole is processed according to the diameter of the pipe, valve or pipe fitting. Therefore, it is important to specify the wall thickness when sending an inquiry. Generally, Fluido’s customers require STD for low-pressure pipe wall thickness, SCH80 for medium pressure, and SCH160 for high pressure. For Special requirements for weld neck flange bore please contact Qingdao Fluido.
The Inside diameter of WN flange bore
| DN | NPS | OD | SCH 5S | SCH 10S | SCH 10 | SCH 20 | SCH 30 | SCH 40S | STD | SCH 40 | SCH 60 | SCH 80S | XS | SCH 80 | SCH 100 | SCH 120 | SCH 140 | SCH 160 | XXS |
| 8 | 1/4 | 13.7 | -- | 10.4 | -- | -- | -- | 9.2 | 9.2 | 9.2 | -- | 7.7 | 7.7 | 7.7 | -- | -- | -- | -- | -- |
| 10 | 3/8 | 17.1 | -- | 13.8 | -- | -- | -- | 12.5 | 12.5 | 12.5 | -- | 10.7 | 10.7 | 10.7 | -- | -- | -- | -- | -- |
| 15 | 1/2 | 21.3 | 18 | 17.1 | -- | -- | -- | 15.8 | 15.8 | 15.8 | -- | 13.8 | 13.8 | 13.8 | -- | -- | -- | 11.7 | 6.4 |
| 20 | 3/4 | 26.7 | 23.4 | 22.5 | -- | -- | -- | 21 | 21 | 21 | -- | 18.9 | 18.9 | 18.9 | -- | -- | -- | 15.6 | 11.1 |
| 25 | 1 | 33.4 | 30.1 | 27.9 | -- | -- | -- | 26.6 | 26.6 | 26.6 | -- | 24.3 | 24.3 | 24.3 | -- | -- | -- | 20.7 | 15.2 |
| 32 | 1 1/4 | 42.2 | 38.9 | 36.7 | -- | -- | -- | 35.1 | 35.1 | 35.1 | -- | 32.5 | 32.5 | 32.5 | -- | -- | -- | 29.5 | 22.8 |
| 40 | 1 1/2 | 48.3 | 45 | 42.8 | -- | -- | -- | 40.9 | 40.9 | 40.9 | -- | 38.1 | 38.1 | 38.1 | -- | -- | -- | 34 | 28 |
| 50 | 2 | 60.3 | 57 | 54.8 | -- | -- | -- | 52.5 | 52.5 | 52.5 | -- | 49.2 | 49.2 | 49.2 | -- | -- | -- | 42.8 | 38.2 |
| 65 | 2 1/2 | 76.1 | 71.9 | 70 | -- | -- | -- | 65.8 | 65.8 | 65.8 | -- | 62.1 | 62.1 | 62.1 | -- | -- | -- | 57 | 48.1 |
| 80 | 3 | 88.9 | 84.7 | 82.8 | -- | -- | -- | 77.9 | 77.9 | 77.9 | -- | 73.7 | 73.7 | 73.7 | -- | -- | -- | 66.6 | 58.4 |
| 90 | 3 1/2 | 101.6 | 97.4 | 95.5 | -- | -- | -- | 90.1 | 90.1 | 90.1 | -- | 85.4 | 85.4 | 85.4 | -- | -- | -- | -- | -- |
| 100 | 4 | 114.3 | 110.1 | 108.2 | -- | -- | -- | 102.3 | 102.3 | 102.3 | -- | 97.2 | 97.2 | 97.2 | -- | 92 | -- | 87.3 | 80.1 |
| 125 | 5 | 141.3 | 135.8 | 134.5 | -- | -- | -- | 128.2 | 128.2 | 128.2 | -- | 122.2 | 122.2 | 122.2 | -- | 115.9 | -- | 109.5 | 103.2 |
| 150 | 6 | 168.3 | 162.8 | 161.5 | -- | -- | -- | 154.1 | 154.1 | 154.1 | -- | 146.4 | 146.4 | 146.4 | -- | 139.8 | -- | 131.8 | 124.4 |
| 200 | 8 | 219.1 | 213.6 | 211.6 | -- | 206.4 | 205 | 202.7 | 202.7 | 202.7 | 198.5 | 193.7 | 193.7 | 193.7 | 188.9 | 182.6 | 177.9 | 173.1 | 174.6 |
| 250 | 10 | 273.1 | 266.3 | 264.7 | -- | 260.4 | 257.5 | 254.6 | 254.6 | 254.6 | 247.7 | 247.7 | 247.7 | 242.9 | 236.6 | 230.2 | 222.3 | 215.9 | 222.3 |
| 300 | 12 | 323.9 | 316 | 314.8 | -- | 311.2 | 307.1 | 304.8 | 304.8 | 303.3 | 295.4 | 298.5 | 298.5 | 288.9 | 281 | 273.1 | 266.7 | 257.3 | 273.1 |
| 350 | 14 | 355.6 | 347.7 | 346 | 342.9 | 339.8 | 336.5 | -- | 336.5 | 333.3 | 325.4 | -- | 330.2 | 317.5 | 307.9 | 300 | 292.1 | 284.2 | -- |
| 400 | 16 | 406.4 | 398 | 396.8 | 393.7 | 390.6 | 387.3 | -- | 387.3 | 381 | 373.1 | -- | 381 | 363.5 | 354 | 344.5 | 333.3 | 325.4 | -- |
| 450 | 18 | 457.2 | 448.8 | 447.6 | 444.5 | 441.4 | 434.9 | -- | 438.1 | 428.7 | 419.1 | -- | 431.8 | 409.5 | 398.5 | 387.3 | 377.9 | 366.7 | -- |
| 500 | 20 | 508 | 498.4 | 496.9 | 495.3 | 488.9 | 482.6 | -- | 488.9 | 477.8 | 466.8 | -- | 482.6 | 455.6 | 442.9 | 431.8 | 419.1 | 408 | -- |
| 550 | 22 | 559 | 549.4 | 547.9 | 546.3 | 539.9 | 533.6 | -- | 539.9 | -- | 514.5 | -- | 533.6 | 501.8 | 489.1 | 476.4 | 463.7 | 451 | -- |
| 600 | 24 | 610 | 598.9 | 597.3 | 597.3 | 590.9 | 581.5 | -- | 590.9 | 575 | 560.8 | -- | 584.6 | 548.1 | 532.2 | 518 | 505.3 | 490.9 | -- |
| 650 | 26 | 660 | -- | -- | 644.2 | 634.6 | -- | -- | 640.9 | -- | -- | -- | 634.6 | -- | -- | -- | -- | -- | -- |
| 700 | 28 | 711 | -- | -- | 695.2 | 685.6 | 679.2 | -- | 691.9 | -- | -- | -- | 685.6 | -- | -- | -- | -- | -- | -- |
| 750 | 30 | 762 | 749.3 | 746.2 | 746.2 | 736.6 | 730.2 | -- | 742.9 | -- | -- | -- | 736.6 | -- | -- | -- | -- | -- | -- |
| 800 | 32 | 813 | -- | -- | 797.2 | 787.6 | 781.2 | -- | 793.9 | 778 | -- | -- | 787.6 | -- | -- | -- | -- | -- | -- |
| 850 | 34 | 864 | -- | -- | 848.2 | 838.6 | 832.2 | -- | 844.9 | 825.9 | -- | -- | 838.6 | -- | -- | -- | -- | -- | -- |
| 900 | 36 | 914 | -- | -- | 898.2 | 888.6 | 882.2 | -- | 894.9 | -- | -- | -- | 888.6 | -- | -- | -- | -- | -- | -- |
This is the dimention for Inside of weld neck flange bore, for size and drawing of weld neck flange please check from Weld Neck Flange Size and Drawing
