Recommended minimum Bolt Torque Values for class 2500 spiral wound gaskets without inner ring.
Bolt Torque values are specified in ft-lb and N-m.
Bolt torques are based on design bolt stress of 60 ksi and a nut factor (K factor) of 0.18.
| NPS (in) |
Class 2500 | Bolt Torque (ft-lb) |
Bolt Torque (N-m) |
|||
|---|---|---|---|---|---|---|
| No. of Bolts |
Bolt Size (in) |
Min | Max | Min | Max | |
| 1/2 | 4 | 3/4 | 17 | 52 | 23.0 | 70.5 |
| 3/4 | 4 | 3/4 | 28 | 83 | 38.0 | 112.5 |
| 1 | 4 | 7/8 | 43 | 130 | 58.3 | 176.3 |
| 1-1/4 | 4 | 1 | 82 | 245 | 111.2 | 332.2 |
| 1-1/2 | 4 | 1-1/8 | 125 | 374 | 169.5 | 507.1 |
| 2 | 8 | 1 | 81 | 242 | 109.8 | 328.1 |
| 2-1/2 | 8 | 1-1/8 | 106 | 319 | 143.7 | 432.5 |
| 3 | 8 | 1-1/4 | 173 | 518 | 234.6 | 702.3 |
1] For typical calculation of bolt torque values refer to article: Calculation of Bolt Torque for Flanged Joint Assembly.
2] Bolt Torque values provided in table above are for guidance only. For actual applied torque values follow gasket vendor recommendations.