5.1 The pumps and piping system conveying CBT
ballast shall be flushed with water before clean ballast is loaded,
discharged or transferred.
5.2 The water for flushing shall be pumped from
a sea chest or dedicated clean ballast tank through the pump and piping
system of the dedicated clean ballast tank and then to a slop tank.
5.3 If sections of the piping system for CBT ballast
are so arranged that they must be flushed with water from the dedicated
clean ballast tanks then the minimum quantity of flushing water to
be provided in such tanks at all times shall be the greater of either
10 times the volume of the piping to be flushed or sufficient to provide
that level in the tank which would allow the piping to run full of
water during the flushing before vortexing starts to admit air into
the piping. Alternative methods for the retention of clean ballast
required by this paragraph shall be to the satisfaction of the Administration.
5.4 After the loading, discharging or transferring
of clean ballast the valves specified in paragraph 4.2.2 shall be
shut and the piping system drained.
5.5 The overboard discharge of all CBT ballast
shall be monitored by an oil content meter.
5.6 The simultaneous discharge of clean ballast
while loading cargo or the simultaneous loading of clean ballast while
discharging cargo shall not be undertaken except where there is an
effective two-valve separation between the ballast and the cargo systems
or when cargo tanks are served by individual pumps.
5.7 Ballast water must not be allowed to free
fall into ballast tanks into which hydrocarbon gases have leaked.
The Dedicated Clean Ballast Tank Operation Manual shall provide either
for such tanks to be gas freed before ballasting or for alternative
tanks to be used to obviate the danger posed by splashing and free
fall of water in tanks containing hydrocarbon gases within the explosive
range.