Q. Determine the proper torque values from the Flange?
Determine the proper torque values from the Flange Closure Sheet. Apply the torque, using a hand torque-measuring wrench, impact wrench or hydraulic wrench, as follows:
Tighten the bolts to 30% of the torque value in sequential order. Repeat the sequence for this torque level until all the nuts cease to move. Do not exceed the 30% torque value because this may cause the flange to cock.
Tighten the bolts to 70% of the torque value in sequential order. Repeat the sequence until all nuts cease to move. Do not exceed the 70% torque value because this may cause the flange to cock.
Tighten the bolts to the full torque value in sequential order. Repeat the sequence until all nuts cease to move. Do not over torque the bolts.
Apply the full torque to the nuts in a clockwise bolting sequence until all the nuts cease to move.
In the event that the gasket cannot be fully seated by the maximum tabulated stress value it will be necessary to obtain engineering approval to further tighten bolts to a specific maximum over torque value. Should this additional tightening fail to uniformly seat the gasket then the joint shall be disassembled and realigned making sure that all tolerances are within the specified limits and made up with a new gasket following the same criteria and limits previously specified.