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overpressure gas blanket at the top of the cargo tanks and slop
tanks.
The inert gas system is designed to comply with the
SOLAS 1974/1978 regulations for tankers (International Maritime
Organization, 1974).
Inert gas generators are used to produce the inert gas with
less than 5% oxygen would be provided. An inert gas main would
be provided with branch connections to all cargo and slops tanks.
A high velocity P,/V valve would be provided on the inert gas
main, to ensure the safe venting of the inert gas containing
hydrocarbon gas without risk of ignition.
A common vent main is installed with branch connections
to all cargo and slop tanks, to facilitate the gas freeing of the tanks
for inspection or maintenance. The system has a high velocity type
P/V valve to ensure that neither a dangerous overpressure nor
under pressure can occur inside any tank whilst it is out of service
for maintenance or inspection.
Tank Washing System
A Crude Oil Washing (COW) system serves the cargo and
slop tanks. The COW is connected to the offloading line and
branched off to all cargo and slop tanks. A booster pump installed
in the system raises the pressure during offloading, should the
loading pump pressure in the COW main be insufficient for crude
oil washing.
Ballast Water System
A ballast water ring main system is used to fill and
discharge the segregated wing ballast tanks. All ring main ballast
piping runs over the deck so as to avoid any possible
contamination with crude oil.
All valves used for routine operation in the ballast water
system are hydraulically operated and remotely controlled from
the central control room.
Fire Water System
The fire water system supplies:
Fire water to:
 Deck foam system
 Helideck foam system
 Accommodation sprinkler system
deluge/foam system to:
 heli-refuelling tanks
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