3.4.1 Where on the basis of the hazard analysis
referred to in paragraph 3.1.2, in order to meet the requirements
referred to in paragraph 3.1.2.1, it has been demonstrated that in
certain sections of the vapour emission control system gases should
be kept outside the flammable range, means should be provided to maintain
such sections of the vapour emission control system gas concentration
in the inerted, diluted or enriched condition with a suitable safety
margin provided. A safety system should be provided in which the signal
of an oxygen and/or hydrocarbon analyser is used to automatically
close the vapour shutoff valve referred to in paragraph 3.2.1 when
the gas concentration in the vapour emission control system approaches
the permitted limits for the inerted, diluted or enriched condition
as given in section 1.2 of these standards.
3.4.2 Where on the basis of the hazard analysis
referred to in paragraph 3.1.2, other operational procedures for explosion
protection are applied such as flow, temperature and pressure control
systems, the safety system referred to in paragraph 3.4.1 should come
into operation if the monitoring of such operational procedures indicates
that the safe limits of the procedures are approached.
3.4.3 At the terminal vapour connection a detonation
arrester should be fitted in close proximity to such connection to
protect against flame propagation originating in the vapour emission
control system being transmitted to the ship's vapour collection system.
3.4.4 Detonation arresters should be tested in
accordance with a test standard acceptable to the competent shoreside
authoritiesfootnote.