DIN 2634 PN 25 Weld Neck Flanges are generally used in high pressure applications, where hot or cold temperatures exist. These steel DIN 2634 weld neck flanges are circumferentially welded into the system at its neck which means that the integrity of the butt welded area can be easily examined by radiography. These PN 25 weld neck flanges reduce the turbulence and erosion inside the pipeline because the bores of both pipe and flange match. This also reduces high stress concentration at the base of the hub of the PN weld neck pipe flange. Such weld neck are favoured in critical applications. The inside diameter of a PN 25 weld neck flange is machined to match the inside diameter of the pipe.

| Pipe Parameter | d1 | Flange Dimension | Neck Size | Hub Size | Screw | Approx. Flange Weight | |||||||||
| DN | ISO | DIN | D | b | k | h1 | d3 | s | r | h2 | d4 | f | No. of | d2 | KG/PCS |
| Holes | |||||||||||||||
| 10 | – | 14 | 90 | 16 | 60 | 35 | 25 | 1.8 | 4 | 6 | 40 | 2 | 4 | 14 | 0.67 |
| 17.2 | – | 90 | 16 | 60 | 35 | 28 | 1.8 | 4 | 6 | 40 | 2 | 4 | 14 | 0.66 | |
| 15 | – | 20 | 95 | 16 | 65 | 38 | 30 | 2 | 4 | 6 | 45 | 2 | 4 | 14 | 0.75 |
| 21.3 | – | 95 | 16 | 65 | 38 | 32 | 2 | 4 | 6 | 45 | 2 | 4 | 14 | 0.75 | |
| 20 | – | 25 | 105 | 18 | 75 | 40 | 38 | 2.3 | 4 | 6 | 58 | 2 | 4 | 14 | 1.07 |
| 26.9 | – | 105 | 18 | 75 | 40 | 40 | 2.3 | 4 | 6 | 58 | 2 | 4 | 14 | 1.07 | |
| 25 | – | 30 | 115 | 18 | 85 | 40 | 42 | 2.6 | 4 | 6 | 68 | 2 | 4 | 14 | 1.29 |
| 33.7 | – | 115 | 18 | 85 | 40 | 46 | 2.6 | 4 | 6 | 68 | 2 | 4 | 14 | 1.28 | |
| 32 | – | 38 | 140 | 18 | 100 | 42 | 52 | 2.6 | 6 | 6 | 78 | 2 | 4 | 18 | 1.88 |
| 42.4 | – | 140 | 18 | 100 | 42 | 56 | 2.6 | 6 | 6 | 78 | 2 | 4 | 18 | 1.86 | |
| 40 | – | 44.5 | 150 | 18 | 110 | 45 | 60 | 2.6 | 6 | 7 | 88 | 3 | 4 | 18 | 2.1 |
| 48.3 | – | 150 | 18 | 110 | 45 | 64 | 2.6 | 6 | 7 | 88 | 3 | 4 | 18 | 2.08 | |
| 50 | – | 57 | 165 | 20 | 125 | 48 | 72 | 2.9 | 6 | 8 | 102 | 3 | 4 | 18 | 2.81 |
| 60.3 | – | 165 | 20 | 125 | 48 | 75 | 2.9 | 6 | 8 | 102 | 3 | 4 | 18 | 2.78 | |
| 65 | 76.1 | – | 185 | 22 | 145 | 52 | 90 | 2.9 | 6 | 10 | 122 | 3 | 8 | 18 | 3.61 |
| 80 | 88.9 | – | 200 | 24 | 160 | 58 | 105 | 3.2 | 8 | 12 | 138 | 3 | 8 | 18 | 4.62 |
| 100 | – | 106 | 235 | 24 | 190 | 65 | 128 | 3.6 | 8 | 12 | 162 | 3 | 8 | 22 | 6.42 |
| 114.3 | – | 235 | 24 | 190 | 65 | 134 | 3.6 | 8 | 12 | 162 | 3 | 8 | 22 | 6.27 | |
| 125 | – | 133 | 270 | 26 | 220 | 68 | 155 | 4 | 8 | 12 | 188 | 3 | 8 | 26 | 8.83 |
| 139.7 | – | 270 | 26 | 220 | 68 | 162 | 4 | 8 | 12 | 188 | 3 | 8 | 26 | 8.61 | |
| 150 | – | 159 | 300 | 28 | 250 | 75 | 182 | 4.5 | 10 | 12 | 218 | 3 | 8 | 26 | 11.67 |
| 166.3 | – | 300 | 28 | 250 | 75 | 192 | 4.5 | 10 | 12 | 218 | 3 | 8 | 26 | 11.29 | |
| 175 | 193.7 | – | 330 | 28 | 280 | 75 | 218 | 5.6 | 10 | 15 | 248 | 3 | 12 | 26 | 13.11 |
| 200 | 219.1 | – | 360 | 30 | 310 | 80 | 244 | 6.3 | 10 | 16 | 278 | 3 | 12 | 26 | 16.61 |
| 250 | – | 267 | 425 | 32 | 370 | 88 | 292 | 7.1 | 12 | 18 | 335 | 3 | 12 | 30 | 23.99 |
| 273 | – | 425 | 32 | 370 | 88 | 298 | 7.1 | 12 | 18 | 335 | 3 | 12 | 30 | 23.48 | |
| 300 | 323.9 | – | 485 | 34 | 430 | 92 | 352 | 8 | 12 | 18 | 395 | 4 | 16 | 30 | 30.74 |
| 350 | 355.6 | – | 555 | 38 | 490 | 100 | 398 | 8 | 12 | 20 | 450 | 4 | 16 | 33 | 47.2 |
| – | 368 | 555 | 38 | 490 | 100 | 398 | 8 | 12 | 20 | 450 | 4 | 16 | 33 | 44.22 | |
| 400 | 406.4 | – | 620 | 40 | 550 | 110 | 452 | 8.8 | 12 | 20 | 505 | 4 | 16 | 36 | 61.69 |
| – | 419 | 620 | 40 | 550 | 110 | 452 | 8.8 | 12 | 20 | 505 | 4 | 16 | 36 | 57.88 | |
| 500 | 508 | – | 730 | 44 | 660 | 125 | 558 | 10 | 12 | 20 | 615 | 4 | 20 | 36 | 89.57 |
| 600 | 610 | – | 845 | 46 | 770 | 125 | 660 | 11 | 12 | 20 | 720 | 5 | 20 | 39 | 114.96 |
| 700 | 711 | – | 960 | 46 | 875 | 125 | 760 | 12.5 | 12 | 20 | 820 | 5 | 24 | 42 | 139.5 |
| 800 | 813 | – | 1085 | 50 | 990 | 135 | 865 | 14.2 | 12 | 22 | 930 | 5 | 24 | 48 | 188.71 |
| 900 | 914 | – | 1185 | 54 | 1090 | 145 | 968 | 16 | 12 | 24 | 1030 | 5 | 28 | 48 | 231.48 |
| 1000 | 1016 | – | 1320 | 58 | 1210 | 155 | 1070 | 17.5 | 16 | 24 | 1140 | 5 | |||
DIN 2632 PN10 Welding Neck/WN Flange Dimensions
API 605/ASME B16.47 Series B Steel Flanges NPS 26 Through NPS 60
ASME B16.5 Threaded Flange Dimensions (150lb-2500lb)