ANSI B16.5 Forged Flanges
Class 1500 Flange Dimensions
ASME B16.5
Class 1500 flanges handle demanding high-pressure systems. RTJ facing becomes common at this rating. All dimensions are in inches.
| NPS | Flange OD | Thickness (min) | RF Diameter | Bolt Circle | # Bolts | Bolt Dia. | Hub Dia. | WN Length | Bore |
|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 4.75 | 0.88 | 1.38 | 3.25 | 4 | 3/4 | 1.19 | 2.75 | 0.88 |
| 3/4 | 5.12 | 1.00 | 1.69 | 3.50 | 4 | 3/4 | 1.50 | 2.75 | 1.09 |
| 1 | 5.88 | 1.12 | 2.00 | 4.00 | 4 | 7/8 | 1.94 | 3.12 | 1.36 |
| 1-1/2 | 7.00 | 1.25 | 2.88 | 4.88 | 4 | 1 | 2.56 | 3.38 | 1.97 |
| 2 | 8.50 | 1.50 | 3.62 | 6.50 | 8 | 3/4 | 3.06 | 3.50 | 2.44 |
| 2-1/2 | 9.62 | 1.75 | 4.12 | 7.50 | 8 | 7/8 | 3.56 | 4.12 | 2.94 |
| 3 | 10.50 | 2.00 | 5.00 | 8.00 | 8 | 1 | 4.25 | 4.25 | 3.57 |
| 4 | 12.25 | 2.50 | 6.19 | 10.00 | 8 | 1-1/4 | 5.31 | 4.88 | 4.57 |
| 5 | 14.75 | 2.75 | 7.31 | 12.25 | 8 | 1-1/2 | 6.44 | 5.50 | 5.66 |
| 6 | 15.50 | 3.25 | 8.50 | 12.75 | 12 | 1-3/8 | 7.56 | 6.00 | 6.72 |
| 8 | 19.00 | 3.62 | 10.62 | 15.75 | 12 | 1-5/8 | 9.69 | 6.75 | 8.72 |
| 10 | 23.00 | 4.25 | 12.75 | 19.00 | 12 | 1-7/8 | 11.75 | 7.75 | 10.88 |
| 12 | 26.50 | 4.88 | 15.00 | 22.50 | 16 | 2 | 13.75 | 8.75 | 12.88 |
| 14 | 29.50 | 5.25 | 16.25 | 25.00 | 16 | 2-1/4 | 15.00 | 9.50 | 14.14 |
| 16 | 32.50 | 5.75 | 18.50 | 27.75 | 16 | 2-1/2 | 17.00 | 10.25 | 16.16 |
| 18 | 36.00 | 6.38 | 21.00 | 30.50 | 16 | 2-3/4 | 19.00 | 11.12 | 18.18 |
| 20 | 38.75 | 7.00 | 23.00 | 32.75 | 16 | 3 | 21.00 | 11.75 | 20.20 |
| 24 | 46.00 | 8.00 | 27.25 | 39.00 | 16 | 3-1/2 | 25.00 | 13.50 | 24.25 |
