Recommended minimum Bolt Torque Values for class 900 spiral wound gaskets Series-B 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 900 | Bolt Torque (ft-lb) |
Bolt Torque (N-m) |
|||
|---|---|---|---|---|---|---|
| No. of Bolts |
Bolt Size (in) |
Min | Max | Min | Max | |
| 26 | 20 | 2-1/2 | 1880 | 5641 | 2548.9 | 7648.2 |
| 28 | 20 | 2-3/4 | 2214 | 6643 | 3001.8 | 9006.7 |
| 30 | 20 | 3 | 2315 | 6945 | 3138.7 | 9416.2 |
| 32 | 20 | 3 | 2474 | 7422 | 3354.3 | 10062.9 |
| 34 | 20 | 3-1/4 | 2852 | 8557 | 3866.8 | 11601.7 |
| 36 | 24 | 3 | 2253 | 6759 | 3054.7 | 9164.0 |
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.