Flat Welding Flange has two types, Slip-on Flange & Plate Flange.
How to lap welding the flat welding flange?
Pipe need to insert into the flange ID to an appropriate position and then lap welding.
Advantage: It is easy for welding, and the total cost is competitive, so it is widely used.
According to the internal pressure calculation, the strength of the flat welding flange is about two-thirds of the corresponding butt welding flange, and the fatigue life is about one-third of the butt welding flange. Therefore, the flat welding flange is only suitable for pipeline systems with relatively low-pressure levels and low-pressure fluctuations, vibrations and spreading.
| 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 | 60.5 | 16x4 | 35 | 1.6 | 11.5 | 22 | 30 | 16 |
| 3/4" | 20 | 26.9 | 100 | 70 | 16x4 | 43 | 1.6 | 13 | 27.5 | 38 | 16 |
| 1" | 25 | 33.7 | 110 | 79.5 | 16x4 | 51 | 1.6 | 14.5 | 34.5 | 49 | 17 |
| 11/4" | 32 | 42.4 | 115 | 89 | 16x4 | 63.5 | 1.6 | 16 | 43.5 | 59 | 21 |
| 11/2" | 40 | 48.3 | 125 | 98.5 | 16x4 | 73 | 1.6 | 17.5 | 49.5 | 65 | 22 |
| 2" | 50 | 60.3 | 150 | 120.5 | 18x4 | 92 | 1.6 | 19.5 | 61.5 | 78 | 25 |
| 21/2" | 65 | 76.1 | 180 | 139.5 | 18x4 | 105 | 1.6 | 22.5 | 77.5 | 90 | 29 |
| 3" | 80 | 88.9 | 190 | 152.5 | 18x4 | 127 | 1.6 | 24 | 90.5 | 108 | 30 |
| 4" | 100 | 114.3 | 230 | 190.5 | 18x8 | 157.5 | 1.6 | 24 | 116 | 135 | 33 |
| 5" | 125 | 139.7 | 255 | 216 | 22x8 | 186 | 1.6 | 24 | 143.5 | 164 | 36 |
| 6" | 150 | 168.3 | 280 | 241.5 | 22x8 | 216 | 1.6 | 25.5 | 170.5 | 192 | 40 |
| 8" | 200 | 219.1 | 345 | 298.5 | 22x8 | 270 | 1.6 | 29 | 221.5 | 246 | 44 |
| 10" | 250 | 273 | 405 | 362 | 26x12 | 324 | 1.6 | 30.5 | 276.5 | 305 | 49 |
| 12" | 300 | 323.9 | 485 | 432 | 26x12 | 381 | 1.6 | 32 | 327.5 | 365 | 56 |
| 14" | 350 | 355.6 | 535 | 476 | 30x12 | 413 | 1.6 | 35 | 359.5 | 400 | 57 |
| 18" | 450 | 457 | 635 | 578 | 33x16 | 533.5 | 1.6 | 40 | 462 | 505 | 68 |
| 20" | 500 | 508 | 700 | 635 | 33x20 | 584 | 1.6 | 43 | 513.5 | 559 | 73 |
| 24" | 600 | 610 | 815 | 749.5 | 36x20 | 692 | 1.6 | 48 | 616.5 | 663 | 83 |
