Section
23 Fuel installations using gases or other low-flashpoint fuels
23.1 General
23.1.1 This Section provides requirements for the survey of a fuel installation
using gases or other low-flashpoint fuels as defined in Pt 1, Ch 3, 1.5 Definitions 1.5.35 (gases or other
low-flashpoint fuels are hereinafter referred to as fuel).
23.1.2 The survey requirements below may be supplemented or replaced by
alternative/equivalent survey requirements for ships using:
Refer to the ‘Alternative/Equivalent Design File’ (AED File) which is to be retained
on board for details of the alternative/equivalent design and how it is operated and
maintained, and of the supplementary or alternative/equivalent survey
requirements.
Prior approval is required for alterations to the alternative/equivalent design and
how it is operated and maintained, to the survey requirements or to the AED
File.
23.2 Annual Surveys
23.2.1 The AED File is to be confirmed as being on board the vessel, as applicable.
Refer to the AED File for supplementary or alternative/equivalent survey
requirements.
23.2.2 The logbooks and maintenance, inspection, testing and operating records are to be
examined with regard to correct functioning of gas detection systems, fuel storage,
bunkering and supply systems, fuel consumers, etc. The operating hours per day of
the reliquefaction plant, gas combustion unit, the boil-off rate, and nitrogen
consumption (for membrane containment systems, etc.) are to be considered together
with gas detection records, as applicable.
23.2.3 The manufacturer/builder instructions and manuals covering the operations, safety and
maintenance requirements and occupational health hazards relevant to fuel storage,
bunkering and supply systems, and other associated systems for use of the fuel, are
to be confirmed as being on board the vessel.
23.2.4 Control, monitoring and safety systems are to be surveyed, including:
- Confirmation that gas detection and other leakage detection equipment
located in tank connection spaces and in compartments containing fuel
storage, bunkering and supply equipment or components or associated systems,
including indicators and alarms, is in satisfactory operating condition.
Maintenance and recalibration of the gas detection systems is to be verified
in accordance with the manufacturers’ recommendations.
- Verification of the satisfactory operation of the control, monitoring and
automatic shutdown systems, as far as practicable, of the fuel supply and
bunkering systems.
- Operational testing, as far as practicable, of the shutdown of ESD protected
machinery spaces.
23.2.5 Piping, hoses, emergency shutdown valves, remote operating valves, relief valves, and
machinery and equipment for fuel storage, bunkering and supply, such as venting,
compressing, refrigerating, liquefying, heating, cooling or otherwise handling the
fuel, are to be examined, as far as practicable. Means for inerting are to be
examined and tested, as far as practicable, including associated alarm testing and
backflow prevention arrangements. Stopping of pumps and compressors upon emergency
shutdown of the system is to be confirmed, as far as practicable.
23.2.6 Control, monitoring and safety systems, including gas leakage and fire detection
equipment for internal combustion engines, fuel cells and other fuel consumers, are
to be tested, as far as practicable.
23.2.7 Examination of the ventilation system, including portable ventilating equipment where
fitted, is to be made for tank connection spaces and spaces containing fuel storage,
bunkering and supply units or components or associated systems, including air locks,
pump rooms, compressor rooms, fuel preparation rooms, fuel valve rooms, control
rooms and spaces containing gas consumers and associated equipment. Ventilated
double-walled piping, ducting containing fuel piping, and associated fans are to be
examined. Where alarms, such as differential pressure and loss of pressure alarms,
are fitted, these are to be operationally tested as far as practicable.
23.2.8 Portable and fixed drip trays and insulation for the protection of the ship’s
structure in the event of leakage are to be examined.
23.2.9 Hazardous area boundaries are to be examined, as far as practicable. Electrical
equipment and bulkhead/deck penetrations, including access openings in hazardous
areas, are to be examined for continued suitability for their intended service and
installation area.
23.2.10 Electrical bonding arrangements in hazardous areas, including bonding straps where
fitted, are to be examined.
23.2.11 Fuel storage, bunkering and supply systems are to be examined, as far as applicable.
Insulation need not be removed, but any deterioration or evidence of dampness is to
be investigated.
23.2.12 Fuel storage arrangements are to be surveyed, including:
- External examination of the storage tanks including the secondary barrier,
if fitted and accessible;
- General examination of the fuel storage hold place;
- Internal and external examination of tank connection spaces;
- External examination of tank, including connecting piping arrangements and
relief valves;
- Verification of satisfactory operation of tank monitoring system, including
vacuum monitoring where fitted;
- Examination and testing of installed bilge alarms and means of drainage of
the compartment;
- Testing of the remote and local closing of the installed main tank
valve;
- Verification of satisfactory operation of the heating arrangements for
structures in cofferdams and other spaces, where fitted.
23.2.13 Fuel bunkering system arrangements are to be surveyed, including:
- Examination of bunkering stations and the fuel bunkering system;
- Verification of satisfactory operation of the fuel bunkering control,
monitoring and shutdown systems.
23.2.14 Fuel supply system arrangements are to be surveyed, including:
- Examination of the fuel supply system during working condition, as far as
practicable;
- Verification of satisfactory operation of the fuel supply system control,
monitoring and shutdown systems;
- Testing of the remote and local closing of the master fuel valve for each
fuel consumer compartment.
23.3 Intermediate Surveys
23.3.2 A random selection of gas detectors, temperature sensors, pressure sensors, level
indicators, and other equipment providing input to the fuel safety system are to be
tested to confirm satisfactory operating condition. The design response of the fuel
safety system upon fault conditions is to be verified.
23.4 Complete Surveys
23.4.2 All piping for fuel storage, bunkering and supply, such as venting, compressing,
refrigerating, liquefying, heating, storing, burning or otherwise handling the fuel,
and nitrogen/inerting installations are to be examined. Removal of insulation from
the piping and opening for examination may be required. Where deemed necessary, a
hydrostatic test to 1,25 times the Maximum Allowable Relief Valve Setting (MARVS)
for the pipeline is to be carried out. After reassembly, the complete piping is to
be tested for leaks. Where water cannot be tolerated and the piping cannot be dried
prior to putting the system into service, the Surveyor may accept alternative
testing fluids or alternative means of testing.
23.4.3 All emergency shutdown valves, check valves, block and bleed valves, master gas
valves, remote operating valves, isolating valves for pressure relief valves in the
fuel storage, bunkering and supply piping systems are to be examined and proven
operable. A random selection of valves is to be opened for examination.
23.4.4 Pressure relief valve arrangements are to be surveyed, including:
- Fuel storage tank pressure relief valves and pressure/vacuum relief valves
for the fuel storage tanks are to be opened for examination, adjusted and
function tested. If the tanks are equipped with relief valves with
non-metallic membranes in the main or pilot valves, such non-metallic
membranes are to be replaced.
- Fuel supply and bunkering piping pressure relief valves are to be opened for
examination, adjusted and function tested. Where a proper record of
continuous overhaul and re-testing of individually identifiable relief
valves is maintained, consideration will be given to acceptance on the basis
of opening, internal examination and testing of a representative sample of
valves, including each size and type of liquefied gas or vapour relief valve
in use, provided there is logbook evidence that the remaining valves have
been overhauled and tested since crediting of the previous Complete
Survey.
- Pressure/vacuum relief valves, rupture discs and other pressure relief
devices for interbarrier spaces, vacuum spaces, pipework double wall spaces
and hold spaces are to be opened, examined, tested and readjusted as
necessary, depending on their design.
23.4.5 Fuel handling equipment, including fuel pumps, compressors, process pressure vessels,
inert gas generators, heat exchangers and other components used in connection with
fuel handling, is to be examined and tested.
23.4.6 Control, monitoring and safety systems, including gas leakage and fire detection
equipment for internal combustion engines, fuel cells and other fuel consumers, are
to be tested.
23.4.7 Hazardous area boundaries, including penetrations, access openings and shaft seals,
are to be examined.
23.4.8 Electrical bonding arrangements in hazardous areas, including bonding straps where
fitted, are to be tested.
23.4.9 Electrical equipment is to be surveyed, including:
- Examination of the physical condition of electrical cables and supports, and
of intrinsically safe, explosion proof or increased safety features of
electrical equipment;
- Functional testing of pressurised equipment and associated alarms;
- Testing of systems for de-energising electrical equipment which is not
certified for use in hazardous areas;
- An electrical insulation resistance test of the circuits terminating in, or
passing through, the hazardous zones and spaces is to be carried out.
23.4.10 Safety systems arrangements are to be surveyed, including:
- Gas detectors, temperature sensors, pressure sensors, level indicators, and
other equipment providing input to the fuel safety system are to be tested
to confirm satisfactory operating condition;
- The design response of the fuel safety system upon fault conditions is to be
verified;
- Pressure, temperature and level indicating equipment are to be calibrated in
accordance with the manufacturer’s requirements.
23.4.11 Liquefied gas fuel storage tanks are to be examined in accordance with the approved
inspection/survey plan, including:
- Tank connection spaces, interbarrier spaces and hold spaces are to be
verified gastight.
- Type C vacuum-insulated independent liquefied gas fuel storage tanks without
access openings need not be examined internally. Tanks, insulation and
support arrangements are to be visually examined. Non-destructive testing
may be required if conditions raise doubts as to their structural integrity.
Where fitted, the vacuum monitoring system is to be examined and records are
to be reviewed.
- All other types of liquefied gas fuel storage tanks are to be
surveyed in accordance with the relevant cargo tank requirements in Pt 1, Ch 3, 9.7 Special Survey I (ships five years old) − General requirements
requirements.
23.4.12 Methyl alcohol (methanol) or ethyl alcohol (ethanol) fuel storage tanks are to be
surveyed in accordance with the approved inspection/survey plan, including:
- Tanks are to be externally examined, including their supporting
arrangements. Where deemed necessary, insulation is to be removed and
non-destructive testing is to be carried out.
- Tanks are to be internally examined and the condition of any
protective coating or corrosion prevention system is to be examined as follows:
- Special Survey I (Ships 5 years old) – None.
- Special Survey II (Ships 10 years old) - One tank.
- Special Survey III (Ships 15 years old) - Two tanks (if more than
one fitted).
- Special Survey IV and subsequent (Ships 20 years old and over) – 50
per cent of tanks (minimum two if more than one fitted).
- Boundaries of tanks are to be tested to the highest point that liquid will
rise to under service conditions. Testing may be undertaken using
low-flashpoint liquid fuel. Tank testing may be specially considered based
upon a satisfactory external examination of the tank boundaries, and a
confirmation from the Master stating that the pressure testing has been
carried out according to the requirements with satisfactory results.
Surveyors may extend the testing as deemed necessary.
23.4.13 Compressed gas fuel storage tanks, including gas bottle arrangements, are to be
internally and externally examined and pressure tested. After reassembly, the
complete arrangement is to be tested for leaks.
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