2.7.1 The procedures set forth in relevant IMO
guidance and established industry guidelines should be observed, as
applicable, with regard to preparation for transfer, and transfer
of cargo and of ballast into cargo tanksfootnote.
2.7.2 The rate of cargo transfer should not exceed
the maximum allowable transfer rate as determined by the lesser of
the following:
-
.1 the venting capacity of the pressure relief
valves in the cargo tank venting system divided by a factor of at
least 1.25.
-
.2 the vacuum relieving capacity of the vacuum
relief valves in the cargo tank venting system; and
-
.3 The rate based on pressure drop calculations
for a given pressure at the facility vapour connection, such that
the pressure in any cargo tank connected to the vapour collection
system does not exceed 80% of the opening set pressure of any pressure
relief valve in the cargo tank venting system.
2.7.3 A cargo tank should not be filled higher
than the level at which the overflow alarm required by paragraph 2.5.1
is set.
2.7.4 A cargo tank should not be opened to the
atmosphere for gauging or sampling while the tanker is connected to
a vapour emission control system unless loading to the tank is stopped,
the tank is isolated from any other tank which is in the process of
being loaded, and precautions are taken to reduce any pressure in
the cargo tank vapour space and prevent an electrostatic spark from
occurring.
2.7.5 If the tanker is equipped with an inert
gas system the isolation valve required by paragraph 2.2.5 should
remain closed during vapour transfer.
2.7.6 Unless equipped with an automatic self-test
and circuit monitoring feature, each tank overflow control system
alarm required by paragraph 2.5.1, on a cargo tank being loaded, should
be tested at the tank for proper operation prior to the start of cargo
transfer.