Welding Neck Orifice Flanges
Class 300
| Nominal size | O | C | R | X | A | Y | TT | No. of holes | Diam. of holes | Diam. of bolts | Diam. of bolt circle | |
| in. | 1″ | 4.88 | 1.5 | 2 | 2.12 | 1.32 | 3.25 | 01/04/07 | 4 | 0.69 | 5/8″ | 3.5 |
| mm. | 124 | 38.1 | 50.8 | 53.8 | 33.5 | 82.6 | 6.4 | 17.5 | 15.9 | 88.9 | ||
| in. | 1 1/2″ | 6.12 | 1.5 | 2.88 | 2.75 | 1.9 | 3.38 | 01/04/07 | 4 | 0.81 | 3/4″ | 4.5 |
| mm. | 155.4 | 38.1 | 73.2 | 69.9 | 48.3 | 85.9 | 6.4 | 20.6 | 19.1 | 114.3 | ||
| in. | 2″ | 6.5 | 1.5 | 3.62 | 3.31 | 2.38 | 3.38 | 01/04/07 | 8 | 0.69 | 5/8″ | 5 |
| mm. | 165.1 | 38.1 | 91.9 | 84.1 | 60.5 | 85.9 | 6.4 | 17.5 | 15.9 | 127 | ||
| in. | 2 1/2″ | 7.5 | 1.5 | 4.12 | 3.94 | 2.88 | 3.5 | 01/04/07 | 8 | 0.81 | 3/4″ | 5.88 |
| mm. | 190.5 | 38.1 | 104.6 | 100.1 | 73.2 | 88.9 | 6.4 | 20.6 | 19.1 | 149.4 | ||
| in. | 3″ | 8.25 | 1.5 | 5 | 4.62 | 3.5 | 3.5 | 03/08/07 | 8 | 0.81 | 3/4″ | 6.62 |
| mm. | 209.6 | 38.1 | 127 | 117.3 | 88.9 | 88.9 | 9.5 | 20.6 | 19.1 | 168.1 | ||
| in. | 4″ | 10 | 1.5 | 6.19 | 5.75 | 4.5 | 3.62 | 01/02/07 | 8 | 0.81 | 3/4″ | 7.88 |
| mm. | 254 | 38.1 | 157.2 | 146.1 | 114.3 | 91.9 | 12.7 | 20.6 | 19.1 | 200.2 | ||
| in. | 6″ | 12.5 | 1.5 | 8.5 | 8.12 | 6.63 | 3.94 | 01/02/07 | 12 | 0.88 | 3/4″ | 10.62 |
| mm. | 317.5 | 38.1 | 215.9 | 206.2 | 168.4 | 100.1 | 12.7 | 22.4 | 19.1 | 269.7 | ||
| in. | 8″ | 15 | 1.62 | 10.62 | 10.25 | 8.63 | 4.38 | 01/02/07 | 12 | 1 | 7/8″ | 13 |
| mm. | 381 | 41.1 | 269.7 | 260.4 | 219.2 | 111.3 | 12.7 | 25.4 | 22.2 | 330.2 | ||
| in. | 10″ | 17.5 | 1.88 | 12.75 | 12.62 | 10.75 | 4.62 | 01/02/07 | 16 | 1.12 | 1″ | 15.25 |
| mm. | 444.5 | 47.8 | 323.9 | 320.5 | 273.1 | 117.3 | 12.7 | 28.4 | 25.4 | 387.4 | ||
| in. | 12″ | 20.5 | 2 | 15 | 14.75 | 12.75 | 5.12 | 01/02/07 | 16 | 1.25 | 1 1/8″ | 17.75 |
| mm. | 520.7 | 50.8 | 381 | 374.7 | 323.9 | 130 | 12.7 | 31.8 | 28.6 | 450.9 | ||
| in. | 14″ | 23 | 2.12 | 16.25 | 16.75 | 14 | 5.62 | 01/02/07 | 20 | 1.25 | 1 1/8″ | 20.25 |
| mm. | 584.2 | 53.8 | 412.8 | 425.5 | 355.6 | 142.7 | 12.7 | 31.8 | 28.6 | 514.4 | ||
| in. | 16″ | 25.5 | 2.25 | 18.5 | 19 | 16 | 5.75 | 01/02/07 | 20 | 1.38 | 1 1/4″ | 22.5 |
| mm. | 647.7 | 57.2 | 469.9 | 482.6 | 406.4 | 146.1 | 12.7 | 35.1 | 31.8 | 571.5 | ||
| in. | 18″ | 28 | 2.38 | 21 | 21 | 18 | 6.25 | 01/02/07 | 24 | 1.38 | 1 1/4″ | 24.75 |
| mm. | 711.2 | 60.5 | 533.4 | 533.4 | 457.2 | 158.8 | 12.7 | 35.1 | 31.8 | 628.7 | ||
| in. | 20″ | 30.5 | 2.5 | 23 | 23.12 | 20 | 6.38 | 01/02/07 | 24 | 1.38 | 1 1/4″ | 27 |
| mm. | 774.7 | 63.5 | 584.2 | 587.2 | 508 | 162.1 | 12.7 | 35.1 | 31.8 | 685.8 | ||
| in. | 24″ | 36 | 2.75 | 27.25 | 27.62 | 24 | 6.62 | 01/02/07 | 24 | 1.62 | 1 1/2″ | 32 |
| mm. | 914.4 | 69.9 | 692.2 | 701.5 | 609.6 | 168.1 | 12.7 | 41.1 | 38.1 | 812.8 |