3.1 The segregated ballast system should be a
system which is "completely separated from the cargo oil and fuel
systems" as required by regulation
1.18. Nevertheless, provision may be made for emergency discharge
of the segregated ballast by means of a connection to a cargo pump
through a portable spool piece. In this case non-return valves should
be fitted on the segregated ballast connections to prevent the passage
of oil to the segregated ballast tanks. The portable spool piece should
be mounted in a conspicuous position in the pump-room and a permanent
notice restricting its use should be prominently displayed adjacent
to it.
3.2 Sliding type couplings should not be used
for expansion purposes where lines for cargo oil or fuel oil pass
through tanks for segregated ballast, and where lines for segregated
ballast pass through cargo oil or fuel oil tanks. This interpretation
is applicable to ships, the keel of which is laid, or which are at
a similar stage of construction, on or after 1 July 1992.