Recommended minimum Bolt Torque Values for class 600 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 600 | Bolt Torque (ft-lb) |
Bolt Torque (N-m) |
|||
|---|---|---|---|---|---|---|
| No. of Bolts |
Bolt Size (in) |
Min | Max | Min | Max | |
| 26 | 28 | 1-7/8 | 884 | 2651 | 1198.5 | 3594.3 |
| 28 | 28 | 2 | 1010 | 3029 | 1369.4 | 4106.8 |
| 30 | 28 | 2 | 1086 | 3257 | 1472.4 | 4415.9 |
| 32 | 28 | 2-1/4 | 1306 | 3919 | 1770.7 | 5313.5 |
| 34 | 28 | 2-1/4 | 1382 | 4146 | 1873.7 | 5621.2 |
| 36 | 28 | 2-1/2 | 1625 | 4876 | 2203.2 | 6611.0 |
| 38 | 28 | 2-1/4 | 1515 | 4544 | 2054.1 | 6160.8 |
| 40 | 32 | 2-1/4 | 1400 | 4200 | 1898.1 | 5694.4 |
| 42 | 28 | 2-1/2 | 1872 | 5617 | 2538.1 | 7615.6 |
| 44 | 32 | 2-1/2 | 1721 | 5163 | 2333.4 | 7000.1 |
| 46 | 32 | 2-1/2 | 1795 | 5384 | 2433.7 | 7299.7 |
| 48 | 32 | 2-3/4 | 2065 | 6196 | 2799.8 | 8400.6 |
| 50 | 28 | 3 | 2676 | 8028 | 3628.2 | 10884.5 |
| 52 | 32 | 3 | 2430 | 7289 | 3294.6 | 9882.6 |
| 54 | 32 | 3 | 2529 | 7588 | 3428.9 | 10287.9 |
| 56 | 32 | 3-1/4 | 2836 | 8507 | 3845.1 | 11533.9 |
| 58 | 32 | 3-1/4 | 2943 | 8830 | 3990.2 | 11971.9 |
| 60 | 28 | 3-1/2 | 3755 | 11266 | 5091.1 | 15274.6 |
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.