17.4.1 Only the indirect system described in 7.2.4.2 should be used.
17.4.2 For a ship engaged
in the carriage of products which readily form dangerous peroxides,
recondensed cargo should not be allowed to form stagnant pockets of
uninhibited liquid. This may be achieved either by:
-
.1 using the indirect system described in 7.2.4.2 with the condenser inside the cargo tank; or
-
.2 using the direct system or combined system
described in 7.2.4.1 and .3 respectively, or the indirect system described in 7.2.4.2 with the condenser outside the cargo tank, and
designing the condensate system to avoid any places in which liquid could collect
and be retained. Where this is impossible inhibited liquid should be added
upstream of such a place.
17.4.3 If the ship is to
carry consecutively products as specified in 17.4.2 with a ballast passage between, all uninhibited liquid
should be removed prior to the ballast voyage. If a second cargo is
to be carried between such consecutive cargoes, the reliquefaction
system should be thoroughly drained and purged before loading the
second cargo. Purging should be carried out using either inert gas
or vapour from the second cargo, if compatible. Practical steps should
be taken to ensure that polymers or peroxides do not accumulate in
the cargo system.