1. General Information
1.1 This guidance is based on ISO 10239 and a system constructed to the requirements of
this standard or equivalent will be acceptable as long as additionally there is suitable
gas detection equipment fitted.
1.2 Possible dangers arising from the use of liquid petroleum gas (LPG) open flame
appliances in the marine environment include fire, explosion and asphyxiation due to
leakage of gas from the installation.
1.3 Consequently, the siting of gas consuming appliances and storage containers and the
provision of adequate ventilation to space containing them is most important.
1.4 It is dangerous to sleep in spaces where gas-consuming open-flame appliances are
left burning, because of the risk of carbon monoxide poisoning. Signage in accordance
with ISO 10239footnote Should be posted.
1.5 LPG is heavier than air and if released, may travel some distance whilst seeking the
lowest part of a space. Therefore, it is possible for gas to accumulate in relatively
inaccessible areas, such as bilges, and diffuse to form an explosive mixture with air,
this is also the case with petrol vapours.
1.6 A frequent cause of accidents involving LPG installations is the use of unsuitable
fittings and improvised “temporary” repairs.
2. Stowage of Gas Cylinders
2.1 LPG cylinders, regulators and safety devices should be stowed on the open deck
(where leakage will not accumulate) or in a compartment that is vapour- tight to the
vessels interior and fitted with a vent and drain, so that gas which may leak can
disperse overboard.
2.2 The vent should be installed near the top of the gas cylinder storage locker. The
drain should be located at the bottom of the gas cylinder storage locker and not be less
than 19mm in diameter, run to the outside of the craft and terminate 75mm or more above
the 'at rest' waterline. The drain and locker ventilation should be 500mm or more from
any opening to the vessels interior.
2.3 The cylinders and associated fittings should be positively secured against movement
and protected from damage in any foreseeable event.
2.4 Any electrical equipment located in cylinder lockers should be certified safe for
use in the potential explosive atmosphere.
3. Cylinders and Attachments
3.1 Each system shall be fitted with a readily accessible, manually operated isolating
valve in the supply pressure part of the system.
3.2 In multiple cylinder installations, in addition to each cylinder shutoff valve there
should be non-return valves near the stop valves. Where there is a change over device
(automatic or manual) it should be provided with non-return valves to isolate any
depleted container.
3.3 When more than one container can supply a system, the system should not be used with
a container removed unless the unattached pipe is fitted with a suitable gas tight plug
arrangement.
3.4 Containers not in use or not being fitted into an installation should have the
protecting cap in place over the container valve.
4. Fittings and Pipework
4.1 In general, systems should comprise rigid pipes made from solid drawn copper alloy
or stainless steel tube. Steel tubing or aluminium or any materials having a low melting
point should not be used.
4.2 Connection between rigid pipe sections should be made with hard solder (minimum
melting point 450 degrees centigrade), appropriate compression or screwed fittings are
recommended for general use for pipework in LPG installations.
4.3 Where a flexible hose is used, it must not exceed 1m in length, it should be
protected from inadvertent damage where appropriate, it should meet the requirement of
EN 1763 class 2, 3 or 4 or equivalent and be installed in a manner that gives access for
inspection along its whole length.
4.4 Pipework, where led through dedicated accommodation sleeping areas, machinery spaces
or high fire risk spaces, should be in solid piping without joints in those spaces. The
piping should pass through bulkheads with a gas tight gland. Where the sleeping
accommodation is common to the wheelhouse or galley then joints in the system should be
kept to a minimum.
4.5 It is recommended to fit a bubble leak detector in the gas outlet pipe as close to
the cylinder as possible.
5. Appliances
5.1 All appliances should be well secured to avoid movement.
5.2 All unattended appliances should be of the room sealed type, i.e. where the gas
flames are isolated in a totally enclosed shield and where the air supply and combustion
gas outlets are piped to open air.
5.3 Cookers and hobs are not considered to be unattended appliances.
5.4 All gas burners and pilot flames should be fitted with a flame supervision device
which will shut off the gas supply to the burner or pilot flame in the event of flame
failure.
5.5 Heaters of a catalytic type should not be used.
6. Ventilation
6.1 The ventilation requirements of a space containing an LPG appliance should be
assessed against an appropriate standard (e.g. Annex B of ISO 10239) and should take
into account gas burning equipment and persons occupying that space.
6.2 Where ventilators required for LPG appliances in intermittent use can be closed,
there should be appropriate signs at the appliance warning of the need to have those
ventilators open before the appliance is used.
7. Gas Detection
7.1 Suitable means for detecting the leakage of gas should be provided in a compartment
containing a gas-consuming appliance or in any adjoining space or compartment into which
the gas, of greater density than air, may seep.
7.2 Gas detectors heads should be securely fixed in the lower part of the compartment in
the vicinity of the gas-consuming appliance and other space(s) into which gas may seep.
In areas where the detector head is susceptible to damage in the lowest part of the
compartment (e.g. machinery space bilge) the detector head should at least be fitted
below the lowest point of ignition.
7.3 A gas detector system of a suitable type should, preferably, be actuated promptly
and automatically by the presence of a gas concentration in air of not greater than 0.5
per cent (representing approximately 25 per cent of the lower explosive limit). The
detection system should incorporate a visible and audible alarm, which can be heard in
the space concerned and the control position with the vessel in operation.
7.4 Gas detection system components (i.e. gas detector head) likely to be in an
explosive air/gas atmosphere should not be capable of igniting that atmosphere.
7.5 In all cases, the arrangements should be such that the detection system can be
tested frequently whilst the vessel is in service and should include a test of the
detector head operation as well as the alarm circuit, in accordance with the
manufacturer’s instructions.
7.6 The detection equipment should be maintained in accordance with the manufacturer’s
requirements.
7.7 Where open flame cooking or heating appliances are installed in or adjacent to
accommodation areas, efficient Carbon Monoxide detector(s) should be fitted See section
14.5.7.
8. Emergency Action
8.1 A suitable notice, detailing the action to be taken when an alarm is given by the
gas detection system, should be displayed prominently in the vessel.
The information given should include the following:
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.1 The need to be ever alert for gas leakage; and
.2 When leakage is detected or suspected, all gas-consuming appliances should be
shut off at the main supply from the container(s). NO SMOKING should be permitted
until it is safe to do so (i.e. the gas leakage has been eliminated and the spaces
fully ventilated)
.3 NAKED LIGHTS SHOULD NEVER BE USED AS A MEANS OF LOCATING GAS LEAKS.
9. Owner/Managing Agent Testing and Maintenance
9.1 It is strongly recommended that LPG systems are tested for leakage regularly. All
connections should be checked by;
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.1 routine observation of the bubble leak detector, if fitted,
.2 observation of the pressure gauge for pressure drop with the appliance valves
closed and cylinder valve opened then closed (if fitted with gauge on supply
pressure side),
.3 visual inspection,
.4 manual leak testing, (without breaking into the system)
.5 testing with soapy water or detergent solution (with appliance-burner valves
closed, and cylinder and system valves open). CAUTION – Do not use solutions
containing ammonia.
.6 if leakage is present, close the cylinder valve and have the system repaired
before further use. WARNING – NEVER USE A NAKED FLAME TO CHECK FOR LEAKS.
.7 Personnel involved in the installation, maintenance, servicing or repairing of
gas systems on boats must hold a current ‘Gas Safe Marine’ Technician
qualification or equivalent.