Recommended minimum Bolt Torque Values for class 600 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 600 | Bolt Torque (ft-lb) |
Bolt Torque (N-m) |
|||
|---|---|---|---|---|---|---|
| No. of Bolts |
Bolt Size (in) |
Min | Max | Min | Max | |
| 1/2 | 4 | 1/2 | 12 | 35 | 16.3 | 47.5 |
| 3/4 | 4 | 5/8 | 23 | 69 | 31.2 | 93.6 |
| 1 | 4 | 5/8 | 31 | 93 | 42.0 | 126.1 |
| 1-1/4 | 4 | 5/8 | 39 | 113 | 52.9 | 153.2 |
| 1-1/2 | 4 | 3/4 | 67 | 201 | 90.8 | 272.5 |
| 2 | 8 | 5/8 | 36 | 107 | 48.8 | 145.1 |
| 2-1/2 | 8 | 3/4 | 50 | 149 | 67.8 | 202.0 |
| 3 | 8 | 3/4 | 72 | 204 | 97.6 | 276.6 |
| 4 | 8 | 7/8 | 155 | 330 | 210.2 | 447.4 |
| 5 | 8 | 1 | 224 | 496 | 303.7 | 672.5 |
| 6 | 12 | 1 | 203 | 496 | 275.2 | 672.5 |
| 8 | 12 | 1-1/8 | 319 | 737 | 432.5 | 999.2 |
| 10 | 16 | 1-1/4 | 349 | 1045 | 473.2 | 1416.8 |
| 12 | 20 | 1-1/4 | 380 | 1045 | 515.2 | 1416.8 |
| 14 | 20 | 1-3/8 | 429 | 1286 | 581.6 | 1743.6 |
| 16 | 20 | 1-1/2 | 610 | 1829 | 827.0 | 2479.8 |
| 18 | 20 | 1-5/8 | 845 | 2457 | 1145.7 | 3331.2 |
| 20 | 24 | 1-5/8 | 776 | 2329 | 1052.1 | 3157.7 |
| 24 | 24 | 1-7/8 | 1072 | 3215 | 1453.4 | 4359.0 |
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.