Section 4 Fuel oil pumps, pipes, fittings, tanks, etc.

4.1.1 Where a power driven pump is necessary for transferring fuel oil, a standby pump is to be provided and connected ready for use, or, alternatively, emergency connections may be made to one of the unit pumps or to another suitable power driven pump.

4.2.1 The power supply to all independently driven fuel oil transfer and pressure pumps is to be capable of being stopped from a position outside the space which will always be accessible in the event of fire occurring in the compartment in which they are situated, as well as from the compartment itself.

4.3.1 All pumps which are capable of developing a pressure exceeding the design pressure of the system are to be provided with relief valves. Each relief valve is to be in closed circuit, i.e. arranged to discharge back to the suction side of the pump and to effectively limit the pump discharge pressure to the design pressure of the system.

4.4.1 Valves or cocks are to be interposed between the pumps and the suction and discharge pipes, in order that any pump may be shut off for opening up and overhauling.

4.5.1 Pipes conveying oil under pressure are to be of seamless steel or other approved material having flanged or welded joints, and are to be placed in sight above the platform in well lighted and readily accessible parts of the machinery spaces. The number of flanged joints is to be kept to a minimum.

4.5.2 Where pipes convey heated oil under pressure the flanges are to be machined, and the jointing material, which is to be impervious to oil heated to 150°C, is to be the thinnest possible, so that flanges are practically metal to metal. The scantlings of the pipes and their flanges are to be suitable for a pressure of at least 1,37 MPa or for the design pressure, whichever is the greater.

4.5.3 The short joining lengths of pipes to the burners from the control valves at the boiler may have cone unions, provided these are of specially robust construction.

4.5.4 Flexible hoses of approved material and design may be used for the burner pipes, provided that spare lengths, complete with couplings, are carried on board.

4.5.5 For requirements relating to flexible hoses, see Pt 5, Ch 12, 7 Flexible hoses.

4.6.1 Transfer, suction and other low pressure oil pipes and all pipes passing through oil storage tanks are to be made of cast iron or steel, having flanged joints suitable for a working pressure of not less than 0,69 MPa. The flanges are to be machined and the jointing material is to be impervious to oil. Where the pipes are 25 mm bore or less, they may be of seamless copper or copper alloy, except those which pass through oil storage tanks. Oil pipes within the engine and boiler spaces are to be fitted where they can be readily inspected and repaired.

4.6.2 For requirements regarding bilge pipes in way of double bottom tanks and deep tanks, see Pt 5, Ch 13, 7.9 Bilge pipes in way of double bottom tanks and Pt 5, Ch 13, 7.10 Bilge pipes in way of deep tanks.

4.7.1 Valves, cocks and their pipe connections are to be so arranged that oil cannot be admitted into tanks which are not structurally suitable for the carriage of oil or into tanks which can be used for the carriage of fresh water.

4.7.2 All valves and cocks forming part of the fuel oil installation are to be capable of being controlled from readily accessible positions which, in the engine and boiler spaces, are to be above the working platform, see also Pt 5, Ch 13, 2.3 Valves − Installation and control.

4.7.3 Every fuel oil suction pipe from a double bottom tank is to be fitted with a valve or cock.

4.8.1 Every fuel oil suction pipe from a storage, settling and daily service tank situated above the double bottom, and every fuel oil levelling pipe within the boiler room or engine room, is to be fitted with a valve or cock secured to the tank.

4.8.2 The valves and cocks mentioned in Pt 5, Ch 14, 4.8 Valves on deep tanks and their control arrangements 4.8.1 are to be capable of being closed locally and from positions outside the space in which the tank is located. The remote controls are to be accessible in the event of fire occurring in the deep tank's space. Instructions for closing the valves or cocks are to be indicated at the valves and cocks and at the remote control positions.

4.8.3 The control for remote operation of the valve on the emergency generator fuel tank is to be in a separate location from the controls for the remote operation of other valves for tanks located in machinery spaces.

4.8.4 In the case of tanks of less than 500 litres capacity, consideration will be given to the omission of remote controls.

4.8.5 Every fuel oil suction pipe which is led into the engine and boiler spaces, from a tank situated above the double bottom outside these spaces, is to be fitted in the machinery space with a valve controlled as in Pt 5, Ch 14, 4.8 Valves on deep tanks and their control arrangements 4.8.2, except where the valve on the tank is already capable of being closed from an accessible position above the bulkhead deck.

4.8.6 Where the filling pipes to deep oil tanks are not connected to the tanks near the top, they are to be provided with non-return valves at the tanks or with valves or cocks fitted and controlled as in Pt 5, Ch 14, 4.8 Valves on deep tanks and their control arrangements 4.8.2.

4.9.1 Settling tanks are to be provided with means for draining water from the bottom of the tanks.

4.9.2 If settling tanks are not provided, the fuel oil bunkers or daily service tanks are to be fitted with water drains.

4.9.3 Open drains for removing the water from oil tanks are to be fitted with valves or cocks of self-closing type, and suitable provision is to be made for collecting the oily discharge.

4.10.1 Relief valves are to be fitted on the oil side of heaters and are to be adjusted to operate at a pressure of 0,34 MPa above that of the supply pump relief valve, see Pt 5, Ch 14, 4.3 Relief valves on pumps. The discharge from the relief valves is to be led to a safe position.

4.11.1 Filling stations are to be isolated from other spaces and are to be efficiently drained and ventilated.

4.11.2 Provision is to be made against overpressure in the filling pipelines. Where any relief valve(s) are fitted for this purpose, they are to discharge to an overflow tank or other safe position.

4.12.1 In passenger ships, provision is to be made for the transfer of fuel oil from any fuel oil storage or settling tank to any other fuel oil storage or settling tank in the event of fire or damage.

4.13.1 Where it is intended to carry fuel oil and water ballast in the same compartments alternatively, the valves or cocks connecting the suction pipes of these compartments with the ballast pump and those connecting them with the fuel oil transfer pump are to be so arranged that the oil may be pumped from any one compartment by the fuel oil pump at the same time as the ballast pump is being used on any other compartment. In passenger ships the arrangement will require to be specially approved.

4.13.2 Where settling or service tanks are fitted, each having a capacity sufficient to permit 12 hours normal service without replenishment, the above requirement may be dispensed with.

4.13.3 Attention is drawn to the statutory regulations issued by National Authorities in connection with the Annex I of MARPOL 73/78Regulations for the Prevention of Pollution by Oil

4.14.1 In the case of deep tanks which can be used for the carriage of fuel oil, cargo oil, water ballast or dry cargo, provision is to be made for blank flanging the oil and water ballast filling and suction pipes, also the steam heating coils if retained in place, when the tank is used for dry cargo, and for blank flanging the bilge suction pipes when the tanks are used for oil or water ballast.

4.14.2 If the deep tanks are connected to an overflow system, the arrangements are to be such that liquid or vapour from other tanks cannot enter the deep tanks when dry cargo is carried in them.

4.15.1 Pipes conveying vegetable oils or similar cargo oils are not to be led through fuel oil tanks, nor are fuel oil pipes to be led through tanks containing these cargo oils. For requirements regarding provision of cofferdams between oil and water tanks, see Pt 3, Ch 3, 4.7 Separation and protection of tanks.

4.16.1 Pipes in connection with compartments used for storing fresh water are to be separate and distinct from any pipes which may be used for oil or oily water, and are not to be led through tanks which contain oil, nor are oil pipes to be led through fresh water tanks.

4.17.1 Where separate fuel oil tanks are permitted, their construction is to be in accordance with the requirements of Pt 5, Ch 14, 4.17 Separate fuel oil tanks 4.17.2 to Pt 5, Ch 14, 4.17 Separate fuel oil tanks 4.17.6, see also SOLAS as amended 2.2.3 Oil fuel tanks .3.2.

4.17.2 In general, the minimum thickness of the plating of service, settling and other oil tanks, where they do not form part of the structure of the ship, is to be 5 mm, but in the case of very small tanks, the minimum thickness may be 3 mm.

4.17.3 For rectangular steel tanks of welded construction, the plate thicknesses are to be not less than those indicated in Table 14.4.1 Plate thickness of separate fuel oil tanks. The stiffeners are to be of approved dimensions.

4.17.4 The dimension given in Table 14.4.1 Plate thickness of separate fuel oil tanks for the breadth of the panel is the maximum distance allowable between continuous lines of support, which may be stiffeners, wash-plates or the boundary of the tank.

4.17.5 Where necessary, stiffeners are to be provided, and if the length of the stiffener exceeds twice the breadth of the panel, transverse stiffeners are also to be fitted, or, alternatively, tie bars are to be provided between stiffeners on opposite sides of the tank.

4.17.6 On completion, the tanks are to be tested by a head of water equal to the maximum to which the tanks may be subjected, but not less than 2,4 m above the crown of the tank. Testing is to be carried out with the requirements of Pt 3, Ch 1, 9 Procedures for testing tanks and tight boundaries.

4.17.7 Separate fuel oil tanks may be permitted on the open deck in the cargo area of oil and chemical tankers, carrying liquid cargoes having a flashpoint not exceeding 60°C and/or toxic liquid cargoes for which toxic vapour detection is specified in column “k” of the table of Chapter 17 Summary of minimum requirements of the IBC Code - International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in BulkAmended by Resolution MEPC.225(64), subject to spill and fire safety considerations. Air and sounding pipes of separate fuel oil tanks are to comply with the requirements of Pt 5, Ch 15, 2.5 Air and sounding pipes.

4.18.1 A fuel oil service tank is a fuel oil tank which contains only the required quality of fuel ready for immediate use.

4.18.2 Two fuel oil service tanks, for each type of fuel used on board, necessary for propulsion and generator systems, are to be provided. Each tank is to have a capacity for at least eight hours' operation, at sea, at maximum continuous rating of the propulsion plant and/or generating plant associated with that tank.

4.18.3 The arrangement of fuel oil service tanks is to be such that one tank can continue to supply fuel oil when the other is being cleaned or opened up for repair.

4.18.4 For ships of less than 500 gross tonnage, the capacity of each fuel oil service tank required by 4.18.2 may be less than for eight hours operation, where the class notation includes a service restriction.

4.19.1 Fuel oil tanks other than those in double bottom compartments shall be located outside ‘Category A’ machinery spaces, see also Pt 3, Ch 3, 4.7 Separation and protection of tanks.

4.19.2 Provisions are to be made for the measurement of fuel oil temperature at the pump suction pipe.

4.19.3 Stop valves are to be provided at the inlet and outlet side of fuel oil strainers.

4.19.4 Pipe joints shall be either welded or spherical type union joints.