Section
11 Thermal oil systems
11.1 General
11.1.1 The
requirements of this Section are applicable to thermal oil systems
heated by oil fired appliances intended for heating of cargo.
11.1.2 Exhaust
gas heating arrangements and heating arrangements intended for own
propulsion will be specially considered.
11.1.3 The
arrangements for storage, distribution and utilisation of thermal
oil under pressure are to comply with the requirements detailed in
this Section. The requirements of Pt 5, Ch 12, 1 General requirements, Pt 5, Ch 12, 2 Fuel oil - General requirements, Pt 5, Ch 12, 3 Fuel oil burning arrangements and Pt 5, Ch 12, 4 Fuel oil pumps, pipes, fittings, tanks, etc. are to be complied
with in so far as they are applicable. In all cases, the following
are to apply:
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Pt 5, Ch 12, 2.6 Precautions against fire 2.6.1, Precautions
against fire.
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Pt 5, Ch 12, 4.1 Control of pumps, Control of pumps.
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Pt 5, Ch 12, 4.2 Relief valves on pumps, Relief valves on pumps.
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Pt 5, Ch 12, 4.4 Pipes conveying oil, Pipes conveying oil.
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Pt 5, Ch 12, 4.6 Valves on tanks and their control arrangements, Valves on tanks and their
control arrangements.
11.1.4 An approved
type of thermal oil is to be used. The proposed thermal oil should
be stated, giving flash point (>55°C), fire point, auto-ignition
temperature and maximum operating temperature.
11.2 Piping
11.2.1 Joints
in thermal oil systems are preferably to be of welded construction,
where used the number of flanged joints is to be kept to a minimum.
11.2.2 Expansion
joints of an approved type or bends are to be provided, where necessary,
in the thermal oil pipe lines. Moreover, the thermal oil pipes are
to be suitably supported and anchored.
11.2.3 All
air release pipes in the system should be fitted with self-closing
cocks and led to the expansion tank.
11.2.4 Suitable
strainers should be fitted on the suction side of the circulating
pumps to filter out any carbonised oil.
11.2.5 Copper
and copper alloys are suspect able for catalytic action with thermal
oil and should not be used.
11.2.8 Pipe
penetrations through bulkheads or decks outside the cargo area are
to be insulated.
11.3 Expansion tank arrangement
11.3.1 A positive
pressure in the heating coils exceeding the external pressure is to
be maintained under all conditions of service irrespective of the
type of cargo to be carried. This can be achieved by means of an atmospheric
expansion tank situated at sufficient height or by pressurising the
expansion tank with an inert gas or compressed air. Arrangements for
atmospheric expansion tanks are to comply with Pt 5, Ch 12, 11.3 Expansion tank arrangement 11.3.3 and arrangements
for pressurized expansion tanks are to comply with Pt 5, Ch 12, 11.3 Expansion tank arrangement 11.3.6.
11.3.3 Means
of approved type are to be provided to ascertain the level in the
thermal oil expansion tank.
11.3.4 The
expansion/header tank is to be fitted with both high and low level
alarms. At low level alarm, the circulation pump is to be stopped
automatically and the thermal oil heater is to be shut down.
11.3.5 The
vent pipe from the expansion tank is to be led to a safe position
on the open deck.
11.3.6 For
expansion tanks provided with an inert gas padding, it is to be guaranteed
that sufficient inert gas will be available to maintain the pressure
in the expansion vessel under all conditions of service.
11.3.7 For
expansion tanks pressurised by compressed air, it is to be guaranteed
that the temperature of the thermal oil in the expansion tank is not
to exceed 50°C in order to avoid oxidation of the thermal oil.
11.3.8 The
expansion vessel is to be provided with a pressure indication and
alarm for the minimum pressure. At low pressure alarm, the circulation
pump is to be stopped automatically and the thermal oil boiler is
to be shut down.
11.3.9 A pressurised
expansion vessel is to be protected against over pressure by a relief
valve, the discharge of which is to be led to a safe position on the
open deck.
11.3.11 The
expansion tank is to be provided with an quick opening valve remotely
controlled from outside the space in which the expansion tank is situated.
11.3.12 The
thermal oil dump tank shall have sufficient capacity to accumulate
the contents of the expansion tank.
11.3.13 Actuating
of the quick opening valve is to initiate stopping of the circulating
pump(s) and shut down of the thermal oil heater.
11.4 Thermal oil heater arrangements
11.4.2 A thermostatic
control or cut-out actuated by the circulating thermal oil temperature,
failure of the circulating thermal oil pumps and ‘flame out’,
is to be incorporated in the oil fired thermal oil heater burner system.
11.4.3 The
oil fired thermal oil heater is to be fitted with temperature sensors
and alarms for fire detection.
11.5
Cross-references
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