Dear Rahyani,
The required bolt torques/bolt load comes with body flange calculation (refer to ASME VIII,App. 2). This depends of design pressure of tube and shell side, bolt diameter, no bolt gasket seating etc.
The hydrostatic condition also as per ASME VIII.
Dear Nirav,
I think if you've done hydrostatic in the shop or field, you do not need repeat the test. But please check the welding connection from corrosion before you do commissioning stage.
Maybe I can explain a little:
* The stack installation is devided by 4:
1. Self supported
2. Guy wire
3. Derrick structure
4. Combination guy wire and derrick structure.
Usually the self supported stack (with variety in diameter) install with wind braker, but not with another.