18.2.1 Arrangements
are to be made in enclosed process plant spaces to prevent contact
of dangerously interreactive substances and of flammable materials
with sources of ignition. In general, compartments containing process
plant are not to exceed 40 m in length, and the boundary bulkheads
are to be `A' Class divisions.
18.2.2 Where,
during operation, process plant spaces or adjacent hazardous zones
contain or are likely to contain flammable and/or explosive mixtures,
special consideration is to be given to the exclusion of all possible
sources of ignition.
18.2.3 All
heated surfaces, e.g. exhaust pipes, boiler uptakes and steam pipes,
are to be effectively lagged or cooled, so that the maximum temperature,
°C, of the surfaces is, in general, not to exceed 70 per cent
of the auto-ignition temperature, °C, of any substances which
may be present in the compartment. In no case is the difference in
these temperatures to be less than 50°C.
18.2.4 Compartments
where a fire hazard exists and which are not continuously manned are
to be provided with an approved fire detection system which shall
give visible and audible warning of the location of the fire in the
control station and, for plant operating at sea (Category 1A), at
the navigating bridge control position.
18.2.5 The
fire main is to be so arranged, and hoses and nozzles provided, that
any part of the compartments or structure associated with the process
plant can be reached with two powerful jets of water, one of which
shall be produced by a single length of hose. The hoses are to be
provided with dual-purpose nozzles capable of producing a jet or a
spray. Special consideration will be given to an exemption from this
requirement in respect of compartments where the use of water would
in itself constitute a hazard.
18.2.6 Each
compartment where the fire hazard so demands is to be provided with
an approved fixed fire-extinguishing system capable of extinguishing
fires involving the materials present. Operation of such a system
at its required output is not to prevent the simultaneous use of the
required jets of water from the fire main. Where carbon dioxide systems
and Halon systems are fitted, due consideration should be given to
the danger of static electricity.
18.2.7 An
adequate number of portable fire extinguishers are to be provided
in each compartment where a fire hazard exists. The number of such
extinguishers will be decided in relation to the nature of the hazard
and the layout of the compartment, but shall not be less than two,
one of which is to be positioned near the entrance. The extinguishing
medium is to be considered in relation to the nature of the hazard
involved.
18.2.8 Means
are to be provided for stopping all fans and, where practicable, closing
all openings which might admit air to the compartment. Such means
should be capable of being operated from a position outside the compartment
and not likely to be rendered inaccessible by a fire in the compartment.
18.2.9 Means
are to be provided for stopping the supply of combustible materials
to the compartment in the event of fire.
18.2.10 The
provision of additional fireman's outfits, each complying with the
requirements of
10 Fire-fighter's outfits, and the necessity for protective clothing, will be specially
considered in relation to the layout of the process plant and the
hazards involved.