Recommended minimum Bolt Torque Values for class 1500 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 1500 | 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 | 7/8 | 71 | 214 | 96.3 | 290.1 |
| 1-1/2 | 4 | 1 | 111 | 332 | 150.5 | 450.1 |
| 2 | 8 | 7/8 | 70 | 211 | 94.9 | 286.1 |
| 2-1/2 | 8 | 1 | 94 | 283 | 127.4 | 383.7 |
| 3 | 8 | 1-1/8 | 155 | 466 | 210.2 | 631.8 |
| 4 | 8 | 1-1/4 | 242 | 725 | 328.1 | 983.0 |
| 5 | 8 | 1-1/2 | 375 | 1124 | 508.4 | 1523.9 |
| 6 | 12 | 1-3/8 | 304 | 911 | 412.2 | 1235.2 |
| 8 | 12 | 1-5/8 | 424 | 1272 | 574.9 | 1724.6 |
| 10 | 12 | 1-7/8 | 583 | 1750 | 790.4 | 2372.7 |
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.