Section 3 Fuel oil burning arrangements

3.1.1 All oil burning equipment is to be capable of operating at defined power/rating levels where specified. Confirmation by the manufacturer of this capability is to be provided to LR, including the specified power/rating parameters, and operating and maintenance regimes. See also Vol 2, Pt 1, Ch 3, 4.1 Availability for operation 4.1.2.

3.1.2 Where steam is required for the main propelling engines, or where steam or thermal fluid is required for auxiliary machinery for Mobility systems or Ship Type systems, or for heating of heavy fuel oil and is generated by burning fuel oil under pressure, there are to be not less than two oil burning units. For auxiliary boilers and thermal oil heaters, a single oil burning unit may be accepted, provided that alternative means, such as an exhaust gas heated boiler or heater, are available for supplying steam or thermal fluid for Mobility systems or Ship Type systems. Where the oil burning unit is not of the monobloc type (i.e. separate register and oil supply unit) each oil burning unit is to comprise a pressure pump, suction filter, discharge filter and, when required, a heater.

3.1.3 Where steam or thermal fluid is required to provide essential services, the number, arrangement and capacity of oil burning units is to be capable of supplying sufficient fuel to allow the steam or thermal fluid required to provide essential services to be generated with any one unit out of action.

3.1.4 Unit pressure pumps are to be entirely separate from the feed, bilge or ballast systems.

3.1.5 In dual fuel oil burning systems for boilers which are primarily designed for operation with residual fuel oil grades, arrangements are to be such that atomising steam cannot be used in combination with distillate fuel oil grades.

3.1.6 In all dual fuel oil burning systems for boilers, the manufacturer of the combustion equipment is to ensure that the full system, including control and monitoring systems, is capable of continuous operation in all conditions for each fuel grade.

3.1.7 Whenever the fuel oil burning units are stopped, shut-off arrangements for fuel oil to the units are to be provided as follows:

1. If the supply fuel oil is under pressure during shut-off to oil burning units, duplicated shut-off valves in series are to be fitted. Cocks are to be fitted to allow manual testing for leakage from each of the valves in the installed condition, they are to be capable of being locked in the closed position and any discharges are to be led to a safe position to ensure that discharge of oil through the test cocks does not present an ignition hazard.

2. If arrangements are such that fuel oil pressure is released through drainage during fuel oil shut-off to oil burning units, a single shut-off device may be accepted subject to approval by LR.

3.1.8 When combined air and fuel/steam/air combustion systems are used for multiple boiler installations, they are to be such that single boiler operation will not be adversely affected by the operation of another boiler system at any time.

3.1.9 Arrangements are to be such that furnace prepurging is completed prior to any burner ignition sequence. The purge time is to be based on a minimum of 4 air changes of the combustion chamber, furnace and uptake spaces. The purge timing is to take account of the air flow rate and the sequence is not to commence until all air registers and dampers as applicable are fully open and the forced draft fans are operating.

3.1.10 The effect of multiple light-off failures is to be assessed and the need to lock out further ignition sequences established.

3.1.11 Means are to be provided so that, in the event of flame failure, the fuel oil supply to the burner(s) is shut off automatically, and an alarm is given, see Vol 2, Pt 7, Ch 3, 9.3 Thermal fluid heaters and Vol 2, Pt 7, Ch 3, 9.4 Incinerators, and Vol 2, Pt 8, Ch 1, 18 Control and monitoring as applicable.

3.1.12 It is to be demonstrated to the Surveyor's satisfaction during trials that burner shut-off times due to flame failure comply with the following requirements and details of the procedures and means used to set this time interval are to be submitted for consideration:

1. The time interval at burner start up between the burner fuel oil valve(s) being opened and then closed in the event of flame failure is to be long enough to allow a stable flame to be established and detected under normal operational circumstances but is to be set to minimise the quantity of fuel oil delivered to the furnace and the possibility of subsequent damage as a result of unintended ignition.

2. The time interval between flame failure detection and closing of burner fuel oil valve(s) is to be long enough to prevent shutdown due to incorrect detection of a flame failure under normal operational circumstances but is to be set to minimise the quantity of unburned fuel oil delivered to the furnace and the possibility of subsequent damage as a result of unintended ignition.

3.1.13 A warning notice is to be fitted in a prominent position at every oil burning unit local manual control station which specifies that burners operated with manual or local overrides in use are only to be ignited after sufficient purging of the furnace and of any additional precautions required when operating in this condition.

3.2.1 In systems where oil is fed to the burners by gravity, duplex filters are to be fitted in the supply pipeline to the burners and so arranged that one filter can be opened up when the other is in use.

3.3.1 A starting-up fuel oil unit, including an auxiliary heater and hand pump, or other suitable starting-up device, which does not require power from shore, is to be provided.

3.3.2 Alternatively, where auxiliary machinery requiring compressed air or electric power is used to bring the boiler plant into operation, the arrangements for starting such machinery are to comply with Vol 2, Pt 7, Ch 3, 12.11 Dead ship condition starting arrangements.

3.4.1 Where burners are provided with steam purging and/or atomising connections, the arrangements are to be such that oil cannot find its way into the steam system in the event of valve leakage.

3.5.1 The burner arrangements are to be such that a burner cannot be withdrawn unless the oil supply to that burner is shut off, and that the oil cannot be turned on unless the burner has been correctly coupled to the supply line.

3.6.1 A quick-closing master valve is to be fitted to the oil supply to each boiler manifold, suitably located so that the valve can be readily operated in an emergency, either directly or by means of remote control, having regard to the machinery arrangements and location of controls.

3.7.1 Provision is to be made, by suitable non-return arrangements, to prevent oil from spill systems being returned to the burners when the oil supply to these burners has been shut off.

3.8.1 For alternately fired furnaces of boilers using exhaust gases and fuel oil, the exhaust gas inlet pipe is to be provided with an isolating device and interlocking arrangements whereby fuel oil can only be supplied to the burners when the isolating device is closed to the boiler.

3.9.1 Where required for the operation of the engines or gas turbines, a suitable fuel treatment plant that may include filtration, centrifuging and/or coalescing is to be provided to reduce the level of water and particulate contamination of the fuel oil to within the engine or gas turbine manufacturer's limits for inlet to the combustion system. The capacity and arrangements of the treatment plant is to be suitable for ensuring availability of treated fuel oil for the maximum continuous rating of the propulsion and electrical generating plant.

3.9.2 Two or more treatment systems are to be provided such that failure of one system will not render the other system(s) inoperative. Arrangements are to ensure that the failure of a treatment system will not interrupt the supply of clean fuel oil to engines or gas turbines used for propulsion and electrical generator purposes. Any treatment equipment in the system is to be capable of being cleaned without interrupting the flow of treated fuel to supply the combustion system.

3.9.3 Where centrifuges are used for fuel oil treatment they are to be type tested in accordance with a standard acceptable to LR and are to be installed on board in accordance with the manufacturer's recommendations. The fuel grades, flow rates and any heating arrangements on board are to be consistent with the specification for type tested centrifuge.

3.9.4 Where heating of the fuel oil is required for the efficient functioning of the fuel oil treatment plant, a minimum of two heating units is to be provided. Each heating unit is to be of sufficient capacity to raise and maintain the required temperature of the fuel oil for the required delivery flow rate.

3.9.5 Heating units may be in circuit with separate treatment systems or provided with connections such that any heating unit can be connected to any treatment system.

3.9.6 Where heating of the fuel oil is required for combustion, not less than two pre-heaters are to be provided, each with sufficient capacity to raise the temperature of the fuel to provide a viscosity suitable for combustion.

3.9.7 Filters and/or coalescers are to be fitted in the fuel oil supply lines to each engine and gas turbine to ensure that only suitably filtered oil is fed to the combustion system. The arrangements are to be such that any unit can be cleaned without interrupting the supply of filtered oil to the combustion system.

3.10.1 Where a fuel oil booster pump is fitted, which is essential to the operation of the main engine, a standby pump is to be provided.

3.10.2 The standby pump is to be connected ready for immediate use but where two or more main engines are fitted, each with its own pump, a complete spare pump may be accepted provided that it is readily accessible and can easily be installed.

3.11.1 Ships intending to use Heavy Fuel Oil (HFO) or Marine Diesel Oil (MDO) when operating outside emissions control areas and marine fuels with a sulphur content not exceeding 0,1 per cent m/m and minimum viscosity of 2 cSt when operating inside emission control areas are to meet the requirements of Vol 2, Pt 7, Ch 3, 3.11 Booster pumps when operating in emissions control areas 3.11.2 or Vol 2, Pt 7, Ch 3, 3.11 Booster pumps when operating in emissions control areas 3.11.3.

3.11.2 The booster pumps which are fitted in compliance with Vol 2, Pt 7, Ch 3, 3.10 Booster pumps are acceptable for use in emissions control areas where these pumps are each suitable for marine fuels with a sulphur content not exceeding 0,1 per cent m/m and minimum viscosity of 2 cSt operation at the required capacity for normal operation of propulsion machinery.

3.11.3 When the booster pumps which are fitted in compliance with Vol 2, Pt 7, Ch 3, 3.11 Booster pumps when operating in emissions control areas 3.11.2, and one pump alone is not capable of delivering marine fuels with a sulphur content not exceeding 0,1 per cent m/m and minimum viscosity of 2 cSt at the required capacity, two booster pumps may operate in parallel to achieve the required capacity for normal operation of propulsion machinery. In this case, one additional fuel oil supply pump is to be provided. The additional booster pump shall, when operating in parallel with one of the booster pumps in 3.10, be suitable for and capable of delivering marine fuels with a sulphur content not exceeding 0,1 per cent m/m and minimum viscosity of 2 cSt at the required capacity for normal operation of the propulsion machinery.

3.12.1 Where pumps are provided for fuel valve cooling, the arrangements are to be in accordance with Vol 2, Pt 7, Ch 3, 3.10 Booster pumps.