Recommended minimum Bolt Torque Values for class 2500 spiral wound gaskets with 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 | 70 | 23.0 | 94.9 |
| 3/4 | 4 | 3/4 | 28 | 110 | 38.0 | 149.1 |
| 1 | 4 | 7/8 | 43 | 174 | 58.3 | 235.9 |
| 1-1/4 | 4 | 1 | 82 | 327 | 111.2 | 443.4 |
| 1-1/2 | 4 | 1-1/8 | 125 | 498 | 169.5 | 675.2 |
| 2 | 8 | 1 | 81 | 322 | 109.8 | 436.6 |
| 2-1/2 | 8 | 1-1/8 | 106 | 425 | 143.7 | 576.2 |
| 3 | 8 | 1-1/4 | 173 | 691 | 234.6 | 936.9 |
| 4 | 8 | 1-1/2 | 290 | 1161 | 393.2 | 1574.1 |
| 5 | 8 | 1-3/4 | 437 | 1749 | 592.5 | 2371.3 |
| 6 | 8 | 2 | 663 | 2651 | 898.9 | 3594.3 |
| 8 | 12 | 2 | 522 | 2087 | 707.7 | 2829.6 |
| 10 | 12 | 2-1/2 | 778 | 3111 | 1054.8 | 4217.9 |
| 12 | 12 | 2-3/4 | 1198 | 4790 | 1624.3 | 6494.4 |
| 14 | - | - | - | - | - | - |
| 16 | - | - | - | - | - | - |
| 18 | - | - | - | - | - | - |
| 20 | - | - | - | - | - | - |
| 24 | - | - | - | - | - | - |
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.