Recommended minimum Bolt Torque Values for class 150 spiral wound gaskets Series-A flanges 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 150 | Bolt Torque (ft-lb) |
Bolt Torque (N-m) |
|||
|---|---|---|---|---|---|---|
| No. of Bolts |
Bolt Size (in) |
Min | Max | Min | Max | |
| 26 | 24 | 1-1/4 | 312 | 1045 | 423.0 | 1416.8 |
| 28 | 28 | 1-1/4 | 287 | 1045 | 389.1 | 1416.8 |
| 30 | 28 | 1-1/4 | 307 | 1045 | 416.2 | 1416.8 |
| 32 | 28 | 1-1/2 | 434 | 1734 | 588.4 | 2351.0 |
| 34 | 32 | 1-1/2 | 402 | 1609 | 545.0 | 2181.5 |
| 36 | 32 | 1-1/2 | 504 | 1897 | 683.3 | 2572.0 |
| 38 | 32 | 1-1/2 | 531 | 1897 | 719.9 | 2572.0 |
| 40 | 36 | 1-1/2 | 496 | 1897 | 672.5 | 2572.0 |
| 42 | 36 | 1-1/2 | 559 | 1897 | 757.9 | 2572.0 |
| 44 | 40 | 1-1/2 | 566 | 1897 | 767.4 | 2572.0 |
| 46 | 40 | 1-1/2 | 591 | 1897 | 801.3 | 2572.0 |
| 48 | 44 | 1-1/2 | 560 | 1897 | 759.3 | 2572.0 |
| 50 | 44 | 1-3/4 | 724 | 2896 | 981.6 | 3926.4 |
| 52 | 44 | 1-3/4 | 752 | 3008 | 1019.6 | 4078.3 |
| 54 | 44 | 1-3/4 | 780 | 3117 | 1057.5 | 4226.1 |
| 56 | 48 | 1-3/4 | 741 | 2964 | 1004.7 | 4018.6 |
| 58 | 48 | 1-3/4 | 767 | 3067 | 1039.9 | 4158.3 |
| 60 | 52 | 1-3/4 | 731 | 2926 | 991.1 | 3967.1 |
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.