The Laws of Fiji
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9.22
Fuel tanks and fuel systems shall be designed, constructed and installed to prevent the spillage of fuel in both normal and abnormal conditions of operation.
Fuel tanks and fuel systems shall be designed, constructed and installed to avoid potential sources of ignition arising from the proximity of machinery or other sources of ignition.
Fuel tanks and fuel systems for fuel of flashpoint less than 60°C shall be designed, constructed and installed to prevent the build-up of explosive fumes and avoid potential sources of ignition that might ignite such fumes.
For the purpose of this paragraph, the fuel system of a ship shall be deemed to have satisfied the required outcomes in subparagraph 9.22.1 and 9.22.3 if it complies with subparagraph 9.22.5 to 9.22.8.
Fuel tanks are classified as portable or non-portable as follows—
- (i)Non-portable fuel tanks — fuel tanks that are either—
- (a)built-in fuel tanks — fuel tanks that are integral to the ship’s hull structure. The requirements for built-in fuel tanks are specified in subparagraph 9.22.5.1 and 9.22.5.2 (further requirements for the fuel systems for such tanks are specified in subparagraph 9.22.7 or 9.22.8); or
- (b)non-portable, freestanding fuel tanks — fuel tanks that are not integral to the hull structure of the ship, but which are nevertheless fitted to or permanently located on the ship, and intended to be refilled in situ. The requirements for non-portable, free-standing fuel tanks are specified in subparagraph 9.22.5.1 and 9.22.5.3. (Further requirements for the fuel systems of non-portable freestanding tanks are specified in subparagraph 9.22.7 or 9.22.8).
- (ii)Portable fuel tanks—
Fuel tanks of 25 L capacity or less, and which are intended to be removed from the ship for filling. The requirements for portable fuel tanks are specified in subparagraph 9.22.5.4.
- 9.22.5.1Common requirements for non-portable fuel tanks of both free-standing and built-in types
- 9.22.5.1.1Location
Non-portable fuel tanks shall not be fitted in the following locations—
- (a)over stairways and ladders;
- (b)over hot surfaces;
- (c)over electrical equipment; and
- (d)In any location where fuel from the tank would leak directly on a source of ignition.
This requirement need not apply where the fuel tank is supplied as an integral part of an engine.
- 9.22.5.1.2Pressure testing
- 9.22.5.1.2.1A non-portable fuel tank shall be pressure tested to an equivalent of 2.5m of fresh water above the top of the tank, or to the maximum head to which the tank may be subject to in service, whichever is the greater.
- 9.22.5.1.2.2The distance from the top of the air pipe or filling pipe, whichever is the greater, shall be taken into account in determining the head.
- 9.22.5.1.2.3Non-portable, free-standing fuel tanks shall be pressure tested prior to installation in the ship.
- 9.22.5.1.3Venting
- 9.22.5.1.3.1A non-portable fuel tank shall be vented to the open air. The size of the vent pipe shall be sufficient to prevent generation of pressure. Where the tank filling is effected by pumping through the filling line, the area of air escape shall not be less than 1.25 times the area of the filling pipe. Where more than one fuel tank is fitted, the vents shall be kept separate.
- 9.22.5.1.3.2The pipe shall terminate in a gooseneck on the open deck.
- 9.22.5.1.3.3Where the diameter of the pipe outlet exceeds 18mm, a corrosion-resistant wire gauze screen shall be fitted. The open area of the screen shall be not less than the cross-section of the vent pipe.
- 9.22.5.1.3.4A short flexible section of hose of length no more than 760mm may be incorporated into the vent pipe for vibration damping or to facilitate installation. The flexible section of hose shall be made of reinforced synthetic rubber of a type resistant to fuel, salt water and vibration.
- 9.22.5.1.3.5The flexible section of hose shall be fastened to the rigid section of the vent with 2 corrosion-resistant clips at each end.
- 9.22.5.1.4Inspection opening
Non-portable fuel tanks, unless they are of the freestanding type and less than 800L capacity, shall be fitted with an inspection opening to facilitate cleaning and inspection.
- 9.22.5.1.5Fuel shut-off
A fuel shut-off valve or cock shall be fitted in each tank outlet line. Non-metallic piping and fittings shall not be fitted in the line between the tank and this shut-off valve or cock. The fuel shut-off valve or cock shall be provided with a means of closing located outside a machinery space in a position not likely to be isolated by a fire in the machinery space. Where remote fuel shut-off arrangements lead from or pass through a machinery space, they shall be capable of operating when exposed to flame and heat from a fire within that space.
NOTE:
Locating the fuel shut-off valve on or near the fuel tank reduces the risk of uncontrolled fuel spillage in the event of a rupture in the pipe between the shut-off valve and the tank.
- 9.22.5.1.6Fuel filling stations
Fuel filling stations shall be located outside machinery spaces and shall be arranged to—
- (a)prevent any possibility of overflow coming into contact with a hot surface; and
- (b)prevent or minimise pollution of the environment by any possible overflow.
- 9.22.5.1.7Filling pipes for non-portable fuel tanks.
- 9.22.5.1.7.1Non-portable fuel tanks shall incorporate a permanent filling pipe. The filling pipe should extend from the open deck to the tank.
- 9.22.5.1.7.2A short flexible section of hose of length no more than 760mm may be incorporated into the filling pipe for vibration damping or to facilitate installation. The flexible section of hose shall be made of reinforced synthetic rubber of a type resistant to fuel, salt water and vibration and shall comply with a relevant national or international standard.
- 9.22.5.1.7.3The flexible section of hose shall be fastened to the rigid section of the filling pipe with 2 corrosion-resistant clips at each end.
NOTES:
- (1)The use of flexible sections of hose in filling pipes that are also used for sounding may prevent proper soundings being taken unless the pipe is straight and a sounding tape is not used.
- (2)Electrical bonding similar to that mandated in subparagraph 9.22.8.10 for fuel systems of flashpoint less than 60°C is considered to be good practice on ships having fuel of flashpoint 60°C or more.
- 9.22.5.2Specific requirements for built-in fuel tanks which are integral to the ship’s hull structure
- 9.22.5.2.1Arrangement
Fuel tanks shall not be located forward of the collision bulkhead. Built-in fuel tanks should be located to reduce the risk of spillage in the event of minor collisions or grounding.
Cofferdams are used to separate fuel tanks from potable water tanks and ballast tanks.
- 9.22.5.2.2Fuels having a flashpoint below 60°C
Built-in fuel tanks shall not be used to contain fuels having a flashpoint below 60°C.
- 9.22.5.2.3Sandwich construction
Sandwich construction shall not be used in way of built-in fuel tanks.
- 9.22.5.2.4Large built-in tanks
Deep tanks and double bottom tanks extending more than half the breadth of the ship shall be subdivided with a longitudinal division.
- 9.22.5.2.5Baffles
Baffle plates shall be fitted in built-in fuel tanks to reduce the surging of the tank contents. Baffles should be fitted at intervals not more than onem along either the longitudinal or transverse axis of the tank. Access openings through baffles should be the minimum size required for inspection and cleaning in order to maintain their effectiveness as baffles.
Baffles are usually fitted perpendicular to the axis of larger dimension. They are not normally provided along both axes.
- 9.22.5.3Specific requirements for non-portable, free-standing fuel tanks
- 9.22.5.3.1Construction
Non-portable, free-standing fuel tanks shall be constructed of carbon steel, stainless steel, copper, marine-grade aluminium alloy or FRP. No part of a metallic fuel tank shall depend on soft solder for tightness.
- 9.22.5.3.2Location
Non-portable, free-standing fuel tanks should be located or arranged to permit inspection of the exterior of the tank and the hull and structure adjacent to the tank.
Non-portable fuel tanks in machinery spaces are also required to comply with the fire rating requirements contained in Part C paragraph 4 (Fire Safety) of the NSCV.
- 9.22.5.3.3Support and securing
Non-portable, free-standing fuel tanks shall be adequately supported and braced to prevent dislodging due to high accelerations that might arise through motions at sea or by a collision. The supports and braces shall be insulated from contact with the tank surfaces with a non-abrasive and non-absorbent material compatible with the tank material.
- 9.22.5.3.4Baffles
Baffles shall be fitted in non-portable, free-standing fuel tanks at a spacing not greater than 1m along the length of the tank (tank major axis), and shall have a thickness not less than that of the tank plating or tank shell laminate.
- 9.22.5.3.5Minimum thickness-metallic tanks
The minimum thickness of metal used in the construction of a non-portable, free-standing fuel tank shall be the greater of the 2 values determined in accordance with Items (a) and (b) as follows—
- (a)The thickness determined using the formulas in subparagraph 9.22.5.3.7, 9.22.5.3.8 or 9.22.5.3.9 as appropriate, based on the dimensions of the largest unsupported panel.
- (b)The thickness determined from the following formula—
Where—
t min = minimum plate thickness of tank, in millimetres; and
UTStank = welded ultimate tensile strength of tank material, in megapascals (MPa).
NOTE: the minimum thickness determined by the formula in subparagraph 9.22.5.3.5(b) equates to 3mm for carbon steel, 2.4mm for 316 stainless steel and between 3.7mm and 4.7mm for aluminium depending upon the grade. Where material of the calculated thickness is not readily available, the preferred stock thickness of material in excess of that required is normally used.
- 9.22.5.3.6Largest unsupported span-carbon steel tanks
When determining the largest unsupported panel for use in subparagraph 9.22.5.3.7 and 9.22.5.3.8, account shall be taken of the support afforded by the following items—
- (a)tank boundaries;
- (b)baffles, where the thickness of the baffle is not less than the thickness of the tank plating in way (see subparagraph 9.22.5.3.4);
- (c)stiffeners, where—
- (i)the thickness of the stiffener is not less than the thickness of the tank plating in way; and
- (ii)the depth of the stiffener is not less than that determined from the following formula—
- d = 12 + b/10
Where—
- d = depth of stiffener in carbon steel in millimetres; and
- b = unsupported span of stiffener, in millimetres.
- 9.22.5.3.7Carbon steel tank of depth not exceeding 2.5m
Where the depth from the top of the filling pipe to the bottom of a non-portable, free- standing carbon steel fuel tank does not exceed 2.5m, the minimum plate thickness of carbon steel shall be obtained from Figure 10, which is developed from the following formula—
t = 0.024ac
Where—
- t = minimum carbon steel plate thickness, in millimetres;
- a = length of minor axis, in millimetres;
- c = corresponding numerical value for the ratio of length of major axis of panel l to length of minor axis of panel a, as given in Table 2; and
- l = length of major axis, in millimetres.
- 9.22.5.3.8Carbon steel tank of depth exceeding 2.5m
Where the depth from the top of the filling pipe to the bottom of a non-portable, free standing carbon steel tank exceeds 2.5m, the minimum plate thickness of carbon steel shall be calculated from the following formula—
Where—
- t = minimum carbon steel plate thickness, in millimetres;
- a = length of minor axis, in millimetres;
- c = corresponding numerical value for the ratio of length of major axis of panel l to length of minor axis of panel a, as given in Table 2;
- h = distance from top of filling pipe to bottom of tank, in metres; and
- l = length of major axis, in millimetres.
Figure 10 — Minimum thickness of fuel tanks plated in carbon steel for heads not exceeding 2.5m
- 9.22.5.3.9Metallic tanks manufactured from metal other than carbon steel
Table 2 — Ratio of major/minor axes of panel (l/a)
l/a 1 1.25 1.5 1.75 2 and over c 0.226 0.258 0.275 0.284 0.288 Values for coefficient c corresponding to values of l/a between those shown in the table may be obtained by linear interpolation.
- 9.22.5.3.9.1Where a fuel tank is manufactured from a metal other than carbon steel, the plate thickness shall be determined from the following formula—
Where—
- T = minimum plate thickness of tank, in millimetres;
- t = minimum plate thickness in millimetres, for carbon steel, determined in accordance with subparagraph 9.22.5.3.7 or 9.22.5.3.8 as appropriate; and
- UTS tank = ultimate tensile strength of tank material, in megapascals (MPa).
- 9.22.5.3.9.2Where the stiffener material is a metal other than carbon steel, the minimum depth of stiffener referred to in subparagraph 9.22.5.3.6 (c) shall be determined from the following formula:
Where—
- D = minimum depth of stiffener in metal other than carbon steel in millimetres;
- d = depth of stiffener for carbon steel, determined in accordance with subparagraph 9.22.5.3.6 (c); and
- UTS tank = ultimate tensile strength of tank material, in megapascals (MPa).
- 9.22.5.3.10FRP non-portable, free-standing fuel tanks — general
Sandwich construction shall not be employed in FRP free-standing fuel tanks. Scantlings for FRP free-standing fuel tanks shall be calculated in accordance with AS 4132.1 and AS 4132.3. Alternatively, the scantlings for FRP free-standing fuel tanks may be determined in accordance with subparagraph 9.22.5.3.11 and 9.22.5.3.12 below.
- 9.22.5.3.11FRP non-portable, free-standing fuel tanks — basis for scantlings
The scantlings for FRP free-standing fuel tanks in subparagraph 9.22.5.3.12 are based on the following minimum requirements for mechanical properties—
- (a)Tensile Strength — 80 MPa;
- (b)Bending Strength — 120 MPa; and
- (c)Modulus of Elasticity—
- (i)Tensile (Es) — 7000 MPa; and
- (ii)Bending (Eb) — 7000 MPa.
A mass per square metre of reinforcement material of 430grams per square metre per millimetre (g/m2/mm) of laminate thickness has been assumed.
- 9.22.5.3.12FRP non-portable, free-standing fuel tanks-tank shell laminate and stiffener requirements
The scantlings of the shell laminate and stiffeners for non-portable, free-standing fuel tanks manufactured from FRP shall be in accordance with Table 3 and Table 4 respectively.
Table 3 — Laminate for free-standing fuel tank shell
Depth of tank (m)A Head (m) B 1.8 2.4 3.0 3.6 Laminate Weight (g/m2)C 0.6 and less 4260 4760 5210 5660 0.9 4540 4980 5430 5825 1.2 4760 5210 5660 6050 1.5 4980 5430 5825 6220 1.8 5210 5660 6050 6380 Legend:
A The depth of the tank shall be measured from the lowest point of the tank panel to the crown of the tank.
B The head shall be measured from the crown of the tank to the top of the air or overflow pipe, whichever is greater, but cannot be less than 1.8m.
C The laminate weights are for stiffeners spaced 460mm apart. Where the spacing differs from 460mm, the laminate shall be modified in direct proportion.
Table 4 — Stiffening of free-standing fuel tanks
Length of stiffeners (m) Minimum head for vertical stiffeners (m) A Head (m) 1.8 2.4 3.0 3.6 Stiffener Section Modulus (cm3)B 0.9 and less 2.25 17.0 22.5 28.5 34.0 1.2 2.40 30.5 40.5 50.0 59.5 1.5 2.55 46.5 62.5 77.5 92.5 1.8 2.70 67.0 90.0 111.5 134.0 Legend:
A The head shall be measured from the centre of the span to the top of the air or overflow pipe, whichever is the greater, but shall not be less than the value given in the table for vertical stiffeners, 1.8m above the crown of the tank for horizontal stiffeners.
B The modulus values are for stiffeners spaced 460mm apart. Where the spacing differs from 460mm, the modulus shall be modified in direct proportion.
- 9.22.5.3.13Internal structure and coatings for non-portable, free-standing fuel tanks constructed of FRP
The minimum laminate for internal baffles in non-portable, free-standing FRP fuel tanks shall not be less than 2400g/m2. A fuel-resistant flow-coat shall be applied to the internal surface, preferably over a heavy resin-rich (2.5:1) chopped strand mat layer using vinylester.
- 9.22.5.4Portable fuel tanks
- 9.22.5.4.1Design
Portable fuel tanks shall be designed to minimise the possibility of overturning and facilitate ease of handling and securing against movement.
- 9.22.5.4.2Manufacture
Portable fuel tanks shall comply with the following—
- (a)unless part of the original engine manufacturer’s equipment, the tank shall be manufactured from corrosion resistant metal or shall be coated with a material to provide protection from corrosion.
- (b)where applicable, the tank shall have mated parts that are galvanically compatible.
- (c)the tank shall have all service and vent openings above the full contents level.
- (d)the tank shall be fitted with a fuel contents gauge.
- (e)AS 2906, unless the tank is part of the original equipment as supplied by the engine manufacturer.
AS 2906 specifies material, design, properties and marking requirements for refillable, portable fuel tanks of capacity up to 25 L.
- 9.22.5.4.3Location
Where a ship is fitted with a flush or sealed deck, portable fuel tanks shall be situated above that deck in such a position as to prevent any fuel from draining to spaces below the deck in the event of a spillage.
- 9.22.5.4.4Fuel lines
Fuel lines for portable fuel tanks shall be of heavy-duty synthetic rubber and shall be fitted with bayonet-type fittings at the tank or engine connection which, when disconnected, will automatically shut off fuel from the tank.
- 9.22.6.1Relief valving
If the closed discharge pressure of a cargo oil pump, fuel transfer pump or fuel pressure pump exceeds the maximum design working pressure of the discharge system, a relief valve discharging back to the suction side of the pump shall be fitted.
- 9.22.6.2Stop valves
Stop valves shall be fitted on the suction and discharge lines of cargo oil, fuel transfer and fuel pressure pumps.
- 9.22.6.3Means of stopping
- 9.22.6.3.1A fuel transfer pump or cargo oil pump shall be fitted with means to stop the pump from both inside and outside the space in which it is located.
- 9.22.6.3.2The remote fuel transfer pump or cargo oil pump shut-down arrangements shall be capable of operating when exposed to flame and heat from a fire within the space containing the pump.
- 9.22.6.4Fuel filters
- 9.22.6.4.1Transparent filter casings of plastic or glass shall be resistant to both mechanical impact and thermal shock, and shall either be fitted with guards or located in protected positions.
- 9.22.6.4.2Where fuel filters are not installed in positions such that any spillage is directed overboard, they shall be designed and installed such that their disassembly will result in minimum spillage.
Fuel filters may be fitted at any position in the fuel system after the fuel shut-off valve or cock referred to in subparagraph 9.22.5.1.5.
Refer to Figure 11.
AS 3570 specifies 61.5°C as the minimum flashpoint for diesel. Australian fuels meet the requirements of AS 3570. Some overseas standards specify a temperature less than 60°C for the minimum flashpoint of diesel.
- 9.22.7.1Fire risk
The fuel system of a ship shall be designed and installed so that failure of any part of the fuel system does not increase the risk of fire to unacceptable levels.
Measures to reduce the risk of fire from a failure in the fuel system include separation from potential sources of ignition, sheathing of fuel piping, spray guarding, and the fitting of alarms.
- 9.22.7.2Fuel tank contents measurement
- 9.22.7.2.1Non-portable fuel tanks shall be fitted with a means for determining the amount of fuel contained in the tank. It shall not be possible for fuel to leak through the measurement device in the event of the tank being overfilled.
- 9.22.7.2.2Where a level indicating gauge glass is fitted on a non-portable fuel tank, it shall be fitted with self-closing valves or cocks. Where the upper end of the gauge glass is connected to the tank through the top plating, only one such self-closing valve or cock at the lower end need be fitted.
- 9.22.7.2.3Fuel tank sounding pipes should not terminate in accommodation spaces. Where such sounding pipes terminate in alleyways, flush deck screwed caps should be fitted.
- 9.22.7.3Fuel tank drains
Non-portable fuel tanks shall be fitted with a drain valve or drain cock, the open end of which shall be blanked with a screwed plug. Alternatively, fuel tanks with a capacity less than 400 L may be provided with just a screwed drain plug.
- 9.22.7.4Rigid fuel piping
- 9.22.7.4.1Unless provided for in subparagraph 9.22.7.5, fuel piping for non-portable fuel tanks shall be of seamless, heavy gauge metal. The piping shall be connected by flanged joints, metal to metal joints of the conical type or other suitable means. Such connections shall be kept to a minimum, and shall be readily visible and accessible.
- 9.22.7.4.2Where cone nipples are used, they shall be welded. Olive-type compression fittings shall not be used.
Figure 11 — Example of a freestanding non-portable fuel tank installation for fuel over 60°C flashpoint.
- 9.22.7.5Flexible fuel piping
- 9.22.7.5.1Flexible fuel piping may be used in fuel systems for non-portable fuel tanks only—
- (a)between the fuel shut-off valve or cock specified in subparagraph 9.22.5.1.5 and the main or auxiliary engine; and
- (b)to conduct any fuel bypass back to the top of the fuel tank.
- 9.22.7.5.2Flexible piping shall have a synthetic rubber inner tube with metal braided reinforcement. It shall be resistant to heat, salt water, petroleum products and shall be a component supplied for the purpose by the engine manufacturer or shall comply with a relevant national or international standard. It shall be installed so as to be readily visible and clear of the bilge, and shall be secured to prevent chafing. Hose fittings shall be in accordance with particular application. Hose clamps should not be used.
- 9.22.7.5.3Flexible piping should be located so as to permit regular inspection and periodic replacement.
- 1.Flexible fuel lines tend to degrade over time.
- 2.Compliance with relevant national or international standards include classification society approval, approval by a national maritime authority (eg AMSA, US Coast Guard), certified compliance with a relevant standard (such as SAE 30R9-Fuel Injection Hose Medium-Pressure Coupled and Uncoupled Synthetic Rubber Tube and Cover). Compliance is only valid if the application is the same as that envisaged by the particular standard or authority, especially supply pipes to fuel injection pumps which are subjected to dynamic pulsing. Fuel returns may also be subjected to dynamic pulsing.
Refer to Figure 12 and Figure 13.
Petrol (gasoline) and liquefied petroleum gas (LPG) both have a flashpoint less than 60°C.
- 9.22.8.1Application
The requirements of this regulation apply to fuel systems in ships with non-portable fuel tanks and which operate on fuel with a flashpoint less than 60°C, with the exception of liquefied petroleum fuel systems. Liquefied petroleum fuel systems as prescribed in Part 5 of this paragraph.
- 9.22.8.2Gravity feed fuel systems
Gravity feed fuel systems shall not be used on engines with non-portable fuel tanks of capacity exceeding 10 L.
- 9.22.8.3Fuel tank capacity
Non-portable fuel tanks should be no larger than that necessary for the intended service of the ship, but should be of sufficient capacity to prevent them having to be filled while in service.
Figure 12 — Example of an under-floor fuel tank installation for fuel with the flashpoint less than 60°C
Figure 13 — Alternative example of an under-floor fuel tank installation for fuel less than 60°C flashpoint.
- 9.22.8.4Fuel tank contents measurement
Non-portable fuel tanks shall be fitted with a means for determining the amount of fuel contained in the tank. It shall not be possible for fuel to leak through the measurement device in the event of the tank being overfilled. The cap provided on the sounding pipe for the insertion of the sounding rod shall have a maximum clear opening of 15mm diameter.
The 15mm limit on caps for sounding pipes is intended to prevent the risk of spillage where a sounding pipe not intended for use as a filling point is used for that purpose. It does not apply where the filling pipe is also designed for taking soundings.
- 9.22.8.5Fuel tank location
- 9.22.8.5.1Non-portable fuel tanks shall be securely installed in a location remote from the engine, exhaust pipes and other potential sources of ignition.
- 9.22.8.5.2Fuel tanks located below the deck or within an enclosed space shall be in a compartment no greater than 4 times the volume of the tanks. The fuel tank compartment shall be liquid and vapour tight to all other compartments.
- 9.22.8.5.3Such fuel tank compartments shall not be used for any purpose other than for housing the fuel tanks. Means to sound the fuel tank space shall be provided.
The likelihood of fuel leaking from a tank is reduced when penetrations such as fuel take-offs, tank vents and inspection covers are arranged to pass through the top of the tank; eg refer to Figure 13 and Figure 14.
- 9.22.8.6Fuel filler pipe
The fuel filler pipe for non-portable fuel tanks shall extend to a point close to the bottom of the tank.
The purpose of this paragraph is to reduce the backflow of inflammable vapours through the filling pipe.
- 9.22.8.7Inspection
Non-portable fuel tanks and associated fittings should be able to be inspected externally.
- 9.22.8.8Ventilation
- 9.22.8.8.1Spaces for non-portable fuel tanks that do not drain overboard shall be adequately ventilated. Venting shall be via a vent pipe to an open space where there is no risk of the escaping vapour igniting or posing any other hazard.
- 9.22.8.8.2Each fuel tank shall also be fitted with a vent pipe, remote from the tank space vent, leading to a similar open space.
- 9.22.8.8.3Vent pipes from tank spaces and fuel tanks shall be separate and non-communicating, and shall be fitted with spark arresters (eg wire gauze diaphragms).
Additional ventilation of the fuel tank space may be provided by a flameproof fan. Alternatively, a gas detector may be fitted, having an audible or visual alarm located at the control position. Guidance for the fitting of flameproof fans is provided in AS 1799.3 Chapter 5.
- 9.22.8.9Electrical connections
Unless required for establishing the amount of fuel in a non-portable fuel tank, electrical connections or wiring shall not be fitted anywhere within the tank space.
- 9.22.8.10Electrical bonding
Electrical bonding shall be provided to protect against the possibility of a spark arising from static charge causing an explosion. Each non-portable metallic fuel tank and metal or metal-plated component of the fuel fill system that may come into contact with fuel shall be earthed so that resistance to earth is less than 10 ohms. When a fill or air pipe contains a non-conducting flexible paragraph, a conductor shall join the metallic paragraphs of the fill or air pipe to protect against a static charge arising during fuel filling.
- 9.22.8.11Fuel piping
- 9.22.8.11.1Unless provided for in subparagraph 9.22.8.12, piping in fuel systems for non-portable fuel tanks shall be of seamless heavy gauge metal. Pipe connections shall be made via flanged joints, metal to metal joints of the conical type or other suitable means, and shall be minimised. Pipe connections shall also be readily visible and accessible.
- 9.22.8.11.2Where cone nipples are used, they shall be welded. Olive-type compression fittings shall not be used.
- 9.22.8.12Flexible piping
- 9.22.8.12.1A short length of flexible piping may be fitted in fuel systems for non-portable fuel tanks in the paragraph of line between the engine bed and the fuel lift pump.
- 9.22.8.12.2Flexible piping shall have a synthetic rubber inner tube with metal braided reinforcement. It shall be resistant to heat, salt water, petroleum products and vibration and shall comply with a relevant national or international standard (SAE J 30 or equivalent). It shall be installed so as to be readily visible and clear of the bilge, and shall be secured to prevent chafing.
- 9.22.8.13Carburettor trays
Carburettors in fuel systems for non-portable fuel tanks (other than down-draught type carburettors) that can flood or overflow shall be fitted with a flame trap and a drip tray. The drip tray should—
- (a)be made of copper or brass;
- (b)be fuel-tight;
- (c)have a corrosion-resistant wire gauze screen sweated into it not less than 13mm below its lip;
- (d)be of a size sufficient to impound any leak from the carburettor; and
- (e)be readily removable.
- 9.22.8.14Engine covers
Engine covers that might be fitted to protect the engine from the weather or salt spray shall be provided with adequate ventilation to prevent the accumulation of explosive fumes.