b) Generally, the bending moments and stresses in air and ventilator pipes are to be calculated at following critical positions:
• at penetration pieces
• at weld or flange connections
• at toes of supporting brackets.
Bending stresses in the net section are not to exceed 0,8 of the specified minimum yield stress or 0,2% proof stress of the steel at room temperature. Irrespective of corrosion protection, a corrosion addition to the net section of 2,0 mm is then to be applied.
Relevant drawing and calculation shall be submitted.