Pipe flange is a method of connecting pipes, valves, pumps and other equipment to form a piping system. It also provides easy access for cleaning, inspection or modification.
Nominal Pipe Size | Outside Diameter of Flange | Diameter of Raised Face | Thickness of Flanges Min. | Diameter of Hub | Length Through Hub | Thread Length Threaded Min. | Bore | Counter-bore Threaded Flange, Min., | Diameter of Bolt Circle | Diameter of Bolt Holes | Number of Bolts | Approxi-mate Weight kgs |
NPS | O | R | tf | X | Y | T | B | Q | W | I | n | |
1/2 | 120 | 34.9 | 22.3 | 38 | 32 | 23 | 22.2 | 23.6 | 82.6 | 22.2 | 4 | 1.73 |
3/4 | 130 | 42.9 | 25.4 | 44 | 35 | 26 | 27.7 | 29.0 | 88.9 | 22.2 | 4 | 2.33 |
1 | 150 | 50.8 | 28.6 | 52 | 41 | 29 | 34.5 | 35.8 | 101.6 | 25.4 | 4 | 3.48 |
1 1/4 | 160 | 63.5 | 28.6 | 64 | 41 | 31 | 43.2 | 44.4 | 111.1 | 25.4 | 4 | 4.00 |
1 1/2 | 180 | 73.0 | 31.8 | 70 | 44 | 32 | 49.5 | 50.3 | 123.8 | 28.6 | 4 | 5.54 |
2 | 215 | 92.1 | 38.1 | 105 | 57 | 39 | 61.9 | 63.5 | 165.1 | 25.4 | 8 | 9.79 |
2 1/2 | 245 | 104.8 | 41.3 | 124 | 64 | 48 | 74.6 | 76.2 | 190.5 | 28.6 | 8 | 13.82 |
3 | 240 | 127.0 | 38.1 | 127 | 54 | 42 | 90.7 | 92.2 | 190.5 | 25.4 | 8 | 11.51 |
4 | 290 | 157.2 | 44.5 | 159 | 70 | 48 | 116.1 | 117.6 | 235.0 | 31.8 | 8 | 19.52 |
5 | 350 | 185.7 | 50.8 | 190 | 79 | 54 | 143.8 | 144.4 | 279.4 | 34.9 | 8 | 32.14 |
6 | 380 | 215.9 | 55.6 | 235 | 86 | 58 | 170.7 | 171.4 | 317.5 | 31.8 | 12 | 41.04 |
8 | 470 | 269.9 | 63.5 | 298 | 102 | 64 | 221.5 | 222.2 | 393.7 | 38.1 | 12 | 70.97 |
10 | 545 | 323.8 | 69.9 | 368 | 108 | 72 | 276.2 | 276.2 | 469.9 | 38.1 | 16 | 100.32 |
12 | 610 | 381.0 | 79.4 | 419 | 117 | 77 | 327.0 | 328.6 | 533.4 | 38.1 | 20 | 133.26 |
14 | 640 | 412.8 | 85.8 | 451 | 130 | 83 | 359.2 | 360.4 | 558.8 | 41.3 | 20 | 152.57 |
16 | 705 | 469.9 | 88.9 | 508 | 133 | 86 | 410.5 | 411.2 | 616.0 | 44.5 | 20 | 185.15 |
18 | 785 | 533.4 | 101.6 | 565 | 152 | 89 | 461.8 | 462.0 | 685.8 | 50.8 | 20 | 256.28 |
20 | 855 | 584.2 | 108.0 | 622 | 159 | 93 | 513.1 | 512.8 | 749.3 | 54.0 | 20 | 315.13 |
24 | 1040 | 692.2 | 139.7 | 749 | 203 | 102 | 616.0 | 614.4 | 901.7 | 66.7 | 20 | 603.79 |