When carrying a cargo referenced to this section, cargo
tank vent outlets shall be provided with readily renewable and effective
flame screens or safety heads of an approved type. Due attention shall
be paid in the design of flame screens and vent heads, to the possibility
of the blockage of these devices by the freezing of cargo vapour or
by icing up in adverse weather conditions. Flame screens shall be
removed and replaced by protection screens, in accordance with 8.2.15,
when carrying cargoes not referenced to this section.