Thread flange is flange with thread connections. It also has FF & RF Types.
The internal hole of the flange is processed into thread and connected with the threaded pipe.
Advantage: It is convenient for installation and maintenance, it could be used on some pipelines where welding is not allowed. Such as for alloy steel flanges. As its sufficient strength, so it is not easy to weld and the welding performance also is not good. Threaded flanges can be selected.
Disadvantage: It is easy leakage if under the condition that the temperature of the pipeline changes sharply or the temperature is higher than 260 ℃ or lower than -45℃. And it is also not suitable for flammable/explosive and highly hazardous locations.
| Size | Pipe OD A | OD | Bolt Circle | Bolt Hole | Sealing Face | Thickness | ID | H | T2 | ||
| Inch | DN | BC | B | R | RF | T1 | |||||
| 1/2" | 15 | 21.3 | 90 | 60.3 | 16x4 | 35 | 1.6 | 9.6 | 22 | 30 | 14 |
| 3/4" | 20 | 26.9 | 100 | 69.9 | 16x4 | 43 | 1.6 | 11.2 | 27.5 | 38 | 14 |
| 1" | 25 | 33.7 | 110 | 79.4 | 16x4 | 51 | 1.6 | 12.7 | 34.5 | 49 | 16 |
| 11/4" | 32 | 42.4 | 115 | 88.9 | 16x4 | 63.5 | 1.6 | 14.3 | 43.5 | 59 | 19 |
| 11/2" | 40 | 48.3 | 125 | 98.4 | 16x4 | 73 | 1.6 | 15.9 | 49.5 | 65 | 21 |
| 2" | 50 | 60.3 | 150 | 120.7 | 18x4 | 92 | 1.6 | 17.5 | 61.5 | 78 | 24 |
| 21/2" | 65 | 76.1 | 180 | 139.7 | 18x4 | 105 | 1.6 | 20.7 | 77.5 | 90 | 27 |
| 3" | 80 | 88.9 | 190 | 152.4 | 18x4 | 127 | 1.6 | 22.3 | 90.5 | 108 | 29 |
| 4" | 100 | 114.3 | 230 | 190.5 | 18x8 | 157.5 | 1.6 | 22.3 | 116 | 135 | 32 |
| 5" | 125 | 139.7 | 255 | 215.9 | 22x8 | 186 | 1.6 | 22.3 | 143.5 | 164 | 35 |
| 6" | 150 | 168.3 | 280 | 241.3 | 22x8 | 216 | 1.6 | 23.9 | 170.5 | 192 | 38 |
