Bolting Dimensions for API Flanges
3000 lb. W.P.
| Nominal Size Inches | Gasket API Number | Number Of Studs | Stud Bolt Size Inches |
|---|---|---|---|
| 3-1/8 | R31 | 8 | 7/8 X 6 |
| 4-1/16 | R37 | 8 | 1-1/8 X 7 |
| 5-1/8 | R41 | 8 | 1-1/4 X 7-3/4 |
| 7-1/16 | R45 | 12 | 1-1/8 X 8 |
| 9 | R49 | 12 | 1-3/8 X 9 |
| 11 | R53 | 16 | 1-3/8 X 9-1/2 |
| 13-5/8 | R57 | 20 | 1-3/8 X 10-1/4 |
| 16-3/4 | R66 | 20 | 1-5/8 X 11-3/4 |
| 20-3/4 | R74 | 20 | 2 X 14-1/2 |
| 26-3/4 | BX168 | 24 | 2 X 17 |
