Strength requirement

Strength requirements for ventilator pipes and their closing devices
D.2.2.4.1 Bending moments and stresses in ventilator pipes are to be calculated at 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  y, where y is 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.
D.2.2.4.2 For standard ventilators of 900 mm height closed by heads of not more than the tabulated projected
area, pipe thicknesses and bracket heights are specified in Table 1.1. Where brackets are required,
three or more radial brackets are to be fitted.
Brackets are to be of gross thickness 8 mm or more, of minimum length 100 mm, and height according to
Table 1.1 but need not extend over the joint flange for the head. Bracket toes at the deck are to be suitably
supported.