Please use calibrated torque wrench or other tool which have control functions.
Be installed in accordance with the recommended torque;
Tighten the nut always in accordance with the symmetrical cross drawing. (See table 1#)
The 5 steps should be followed:
a. Initial tighten all nuts by hand, the big nut can use small wrench;
b. Tighten each nuts by 30% of recommended torque;
c. Tighten each nuts by 60% of recommended torque;
d. Tighten each nuts by 100% of recommended torque;
e. Tighten all nuts in clockwise direction to make sure all the nuts reach required torque.
Recommended Bolt Torque Chart (Table 1#)
| Nominal Diameter of Bolt | Torque Value | |
| (Inch) | (Ft.lbs) | (N.m) |
| 1/2 | 30 | 41 |
| 5/8 | 60 | 82 |
| 3/4 | 100 | 135 |
| 7/8 | 160 | 217 |
| 1 | 245 | 332 |
| 1-1/8 | 355 | 481 |
| 1-1/4 | 500 | 678 |
| 1-3/8 | 680 | 922 |
| 1-1/2 | 800 | 1,085 |
| 1-5/8 | 1,100 | 1,491 |
| 1-3/4 | 1,500 | 2,034 |
| 1-7/8 | 2,000 | 2,712 |
| 2 | 2,200 | 2,983 |
| 2-1/4 | 3,180 | 4,312 |
| 2-1/2 | 4,400 | 5,966 |
| 2-3/4 | 5,920 | 8,026 |
| 3 | 7,720 | 10,565 |
| 3-1/4 | 8.400 | 11.389 |
| 3-1/2 | 9,000 | 12,202 |
| 3-3/4 | 9.600 | 13,016 |
| 4 | 10,000 | 13,558 |
Notes:
> Recommended bolt torque is based on deriving a minimum gasket seating stress of 7,500 psi;
> Bolt torque values listed assume a lubricated stud bolt resulting in a 0.16 friction factor;
> Recommended torque values are based on using weld-neck (integral) flanges;
> Different sealing loads. 30 psi bolt stress may exceed the design allowable stress levels for certain stud bolt materials.