Section 6 Fuel System

601. General

Design, materials, installation and tests of permanently installed gasoline and diesel fuel system and permanently installed fuel tanks for inboard engines for propulsion and auxiliary and outboard en- gines are to be comply with the requirements in this Section.

602. Fuel system

1. Materials and design

(1) The filling, storage, venting and fuel-supply arrangements and installations are to be designed and installed so as to minimize the risk of fire and explosion.

(2) Individual components of the fuel system, and the fuel system as a whole, are to be designed

to withstand the combined conditions of pressure, vibration, shocks, corrosion and movement en- countered under normal operating conditions and storage.

(3) Each component of the fuel system, and the fuel system as a whole, are to be capable of oper-

ation within an ambient temperature range of -10 °C to +80 °C, without failure or leakage, and be capable of being stored without operation within an ambient temperature range of -30 °C to

+80 °C, without failure or leakage.

(4) All materials used in the fuel system are to be resistant to deterioration by its designated fuel and to other liquids or compounds with which it may come into contact under normal operating conditions, e.g. grease, lubricating oil, bilge solvents and sea water.

(5) The only outlets for drawing fuel from the fuel system are to be :

(A) Plugs in petrol filter bowls intended solely for the purpose of servicing the filter,

(B) Plugs or valves in diesel filter bowls intended solely for the purpose of servicing the filter.

(6) Each metal or metallic plated component of a petrol fuel fill system and fuel tank which is in contact with the fuel are to be grounded so that its resistance to the craft's ground is less than one ohm. Grounding wires are not to be clamped between a hose and its pipe or spud.

(7) Fuel filling systems are to be designed to avoid blowback of fuel through the fill fitting. Fuel systems are to be tested in accordance with 4 (3).

(8) Provision is to be made to prevent fuel overflow from the vent opening from entering the craft

or the environment.

(9) All fuel system components in the engine compartment, excluding permanently installed fuel

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tanks, which are tested in accordance with ISO 21487(e.g. filters, water separators, and hoses) are to individually, or as installed in the craft, be capable of withstanding a 2.5 min fire test as specified in ISO 7840 Annex A. Fasteners supporting metal fuel lines constitute an exception to this requirement.

(10) Copper-base alloy fittings may be used for aluminium tanks if protected by a galvanic barrier to reduce galvanic corrosion.

(11) A means to determine fuel tank level or quantity is to be provided.

2. Fuel pipes, hoses, connections and accessories

(1) Fuel filling lines

(A) The minimum inside diameter of the filling pipe system is to be 31.5 mm and the minimum inside diameter of fuel filling hoses is to be 38 mm.

(B) Fuel filling hoses located in the engine compartment are to be fire resistant, of type A1 or A2 in accordance with ISO 7840. Fuel filling hoses outside the engine compartment are to

be of either type A1 or A2 in accordance with ISO 7840, or of type B1 or B2 in accord-

ance with ISO 8469.

(C) Fuel filling lines are to be self-draining to the tank when the craft is in its static floating position.

(D) Fuel filling lines are to run as directly as practicable, preferably in a straight line from the deck plate or equivalent filling point to the tank.

(E) The fuel filling system is to be designed so that accidental fuel spillage does not enter the

craft when it is in its static floating position.

(F) The distance between compartment ventilation openings and fuel filling openings is to be at

least 400 mm, except where the craft's coaming, superstructure or hull creates a barrier to prevent fuel vapour entering the craft through the ventilation opening.

(G) The fuel filling point are to be marked “petrol” or “diesel” and/or with a symbol specified

in ISO 11192 to identify the type of fuel to be used.

(2) Vent lines

(A) Each fuel tank is to have a separate vent line.

(B) Vent hoses located in the engine compartment are to be fire resistant, of type A1 or A2 in accordance with ISO 7840. Vent hoses outside the engine compartment are to be of either type A1 or A2 in accordance with ISO 7840, or type B1 or B2 in accordance with ISO 8469.

(C) The cross-sectional area of any vent component is not to be less than 95 mmË(inside diame- ter 11 mm).

(D) Vent lines are not to have valves other than those that permit free flow of air and prevent flow of liquid both in and out of the tank.

(E) Vent lines are to be self-draining when the craft is in its static floating position.

(F) The distance between compartment ventilation openings and fuel vent openings is to be at least 400 mm, except where the craft's coaming, superstructure or hull creates a barrier to prevent fuel vapour entering the craft through the ventilation opening.

(G) The vent line is to be arranged to minimize intake of water without restricting the release of vapour or intake of air and is not to allow fuel or vapour overflow to enter the craft.

(H) The vent-line termination or a gooseneck in the vent-line routing is to be arranged at suffi-

cient height to prevent spillage of fuel through the vent line during filling and entry of wa- ter under normal operating conditions of the craft. On mono-hull sailing craft, the vent line is to be arranged to minimize the risk of fuel spillage or entry of water through the vent when sailing at a heel angle of up to 30°.

(I) The vent lines on all fuel installations are to incorporate a flame arrester device.

(J) For components installed in the vent line, the requirements in (2) apply.

(K) For

vent-line components in the engine compartment, with the ability to capture fuel, the

fire test requirements in 1 (9) apply.

(3) Fuel distribution lines and fuel return lines

(A) pMeer‒tanlicfkueell odristerqibuuivtiaolnentanmdetraeltuwrnithlinaesnoarmeintoal bwealml atdheickonfessseaomfleasts leaansntea0l.e8dmcmop. pAerluomrincioupm-

lines may be used for diesel fuel.

(B) Rigid fuel distribution and return lines are to be connected to the engine by a flexible hose

section. Support is to be provided within 100 mm line on the rigid side of the connection.

(C) Connections in rigid fuel distribution or return lines

of the connection to the metal supply are to be made with efficient screwed,

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compression, cone, brazed or flanged joints.

(D) Flexible fuel distribution and return hoses are to be used where relative movement of the craft structures supporting the fuel lines would be anticipated during normal operating conditions.

(E) Flexible fuel distribution and return hoses are to be accessible for inspection and maintenance.

(F) Petrol distribution and return hoses are to be fire-resistant, type A1 hoses in accordance with ISO 7840, except hoses entirely within the splash well at the stern of the craft con-

nected directly to an outboard engine, which are to be type B1 or B2 hoses in accordance

with ISO 8469 or A1 or A2 hoses in accordance with ISO 7840.

(G) Diesel-fuel distribution and return hoses are to be fire-resistant, type A1 or A2 hoses in ac- cordance with ISO 7840.

(H) Fuel distribution and return lines are to be properly supported and secured to the craft struc- ture above bilge water level, unless specifically designed for immersion or protected from

the effects of immersion.

(I) There are to be no joints in fuel distribution and return pipes or hoses other than those re- quired to connect required fuel-line components, e.g. filters and bulkhead connections.

(J) Fuel distribution lines to petrol engines are to be designed or installed to prevent fuel si-

phoning out of the tank following a failure in the system. The following examples illustrate how this can be achieved:

(a) routing all parts of fuel lines, from which an assumed leakage can enter the craft,

above the level of the tank top when the craft is in its static floating position, including fuel-containing parts on the engine; or

(b) fitting an anti-siphon valve at the tank fittings with a rated siphon-protection head great-

er than that required to avoid the siphon effect; or

(c)

fitting a manual shut-off valve, which are to be capable of being closed from an in- dicated accessible location outside the engine compartment, in a position that is

self-draining from the valve to the tank; or

(d) fitting an electrically operated valve at the tank withdrawal fitting which is activated to

open only when the engine is running

override type is acceptable for starting.

(K) Fuel distribution lines to diesel engines to with a manual shut-off valve. This valve is

or the starting device is operated. A momentary

either meet the requirements of (J), or be fitted to be capable of being closed from an indicated

accessible location outside the engine compartment. If electrically operated valves are used,

they are to be equipped with a manual emergency operating or by-passing device.

(L) Diverting valves in diesel return lines are to ensure that the return line flow is not restricted.

(4) Hose fittings and hose clamping

(A) Fuel hoses are to be secured to the pipe, spud or fitting by metal hose clamps or be equip- ped with permanently attached end fittings such as a swaged sleeve or a sleeve and thread-

ed insert.

(B) Pipes, spuds or other fittings for hose connection with hose clamps are to have a bead, flare, series of annular grooves or serrations. The fuel-tank spud constitutes an exception to

this requirement. Continuous helical threading knurls or grooves, which can provide a path

for fuel leakage, are not to be used.

(C) Spuds or other fittings for hose connection with hose clamps are to have a nominal outer diameter which is the same as the nominal inner diameter of the hose, and should be chos- en from a series of preferred numbers, e.g. 3.2, 4, 5, 6.3, 8, 10, 12.5 16, 20, 25, 31.5, 40,

50, 63.

(D) Hose connections designed for a clamp connection are to have a spud at least 25 mm long.

(E) Hose connections having a nominal diameter of more than 25 mm are to have two hose clamps. The spud is to be at least 35 mm long, to provide space for the clamps.

(F) Spuds intended for hose connection are to be free from sharp edges that could cut or abrade the hose.

(G) Hose clamps are to be made of CrNi 18-8 stainless steel, or equivalent, and be reusable.

Clamps depending solely on spring tension are not to be used. The nominal clamp band width is to be at least 8 mm for nominal outside hose diameters up to and including 25 mm

and at least 10 mm for bigger hoses. Clamps are to be of fitted according to the clamp manufacturer's requirements.

(H) Clamps are to be installed to fit directly on the hose and

the correct size and are to be

are not to overlap each other.

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Clamps are to be installed behind the bead, if any, or fully on the serrations on spuds at least one clamp width from the end of the hose.

(5) Valves

(A) Manually operated valves are to be designed with positive stops in the open and closed po- sitions or are to clearly indicate their open and closed positions.

(B) The integrity and tightness of a valve are not to depend solely on spring tension.

(C) Threaded valve housing covers that can be exposed to an opening torque when the valve is

operated are to be secured against unintentional

(6) Fuel filters

(A) Petrol fuel systems are to be equipped with engine.

(B) Diesel fuel systems are to be equipped with at

opening by a device that can be reused.

a fuel filter, which may be fitted on the least one fuel filter and one water separator.

The two functions may be combined in one unit.

(C) Each filter is to be independently supported on the engine or craft structure.

(7) Labelling

All components (e.g. filters, pumps and water separators) that have passed the test for fire re- sistance specified in ISO 7840 Annex A, are to be labelled or marked with the following:

(A) Manufacturer's name or trademark;

(B) ISO 10088, fire resistant;

(C) Type of fuel or fuels for which the component is suitable.

3. Installation

(1) The fuel system is to be permanently installed. All component parts, except small connectors and fittings and short sections of flexible hoses, are to be independently supported.

(2) All valves and other components intended to be operated or observed during normal operation of the craft, or for emergency purposes, are to be readily accessible. All other components of the system are to be accessible. Tanks need not be accessible for removal.

(3) The clearance between a petrol fuel tank and a combustion engine is not to be less than mm.

(4) The clearance between a petrol tank and dry exhaust components is not to be less than mm, unless an equivalent thermal barrier is provided.

(5) Fuel system electrical components are to be installed in accordance with ISO 10133 or

13297.

100

250

ISO

(6) Fuel tanks and components of petrol fuel systems are not to be installed directly above batteries unless the batteries are protected against the effects of fuel leakage.

4. Tests

(1) After installation, the fuel system is to be subject to pressure test as follows;

(A) A complete fuel system as installed in the craft is to be subject to the test pressure with the pressure of 20 kPa. and the pressure-drop method is to be used. The time during which the system is exposed to the pressure is to be equal to the greater of the following two values: 1.5 s per litre of tank capacity or 5 min, up to a maximum of 30 min. Tanks with a capacity of less than 200 L are to be tested for at least 5 min. During this test, fuel-fill deck plates and vent-line through-hull fittings may be replaced by plugs. The fuel con- nection at the fuel feed pump of the engine is to be disconnected and sealed. Anti-siphon valves and other fuel valves are to be open.

(B) A component or fuel system is not to show any leakage during pressure testing for 5 min.

(2) Fuel system components that are small enough, such as fuel valves, and required to be fire test- ed according to 1 (9) are to be tested as specified in ISO 7840 Annex A. The component to

be tested is to be a complete assembly and include all accessories intended to be attached di- rectly to the component.

(3) There are to be no blow back of fuel through the fill fitting when filling at a rate of 30 L/min from 25 % to 75 % of the capacity on the tank label. For fuel tanks of 100 L capacity or less, the fill rate may be reduced to 20 L/min. The test to determine compliance with this is to be performed on at least one craft or a representative installation.

603. Fuel tanks

1. Design general

(1) Fuel tanks, lines and hoses are to be secured and separated or protected from any source of

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significant heat. The material of the tanks and their method of construction are to be according to their capacity and the type of fuel. All tank spaces are to be ventilated.

(2) Petrol fuel is to be kept in tanks which do not form part of the hull and are insulated from

the engine quarters.

compartment and from all other source of ignition and are separated from living

(3) Diesel fuel may be kept in tanks that are integral with the hull.

(4) Metal tanks are to be designed or installed so that no exterior surface will trap water.

(5) Rigid fuel suction tubes and filling pipes which extend near the tank bottom are to have suffi- cient clearance to prevent contact with the bottom during normal operation of the craft.

(6) Non-integral tanks shall be installed so that the loads due to the mass of the full tank are safe- ly introduced into the structure, with due consideration given to upward and downward accel-

eration due to the craft's movements at maximum speed in the sea. All non-integral tank sup-

ports, chocks or hangers are to either be separated from the surface of metal tanks by a non-metallic, non-hygroscopic, non-abrasive material or welded to the tank.

(7) If baffles are provided, the total open area provided in the baffles is to be not greater than 30

% of the tank cross section in the plane of the baffle.

(8) Baffle openings are to be designed so that they do not prevent the fuel flow across the bottom or trap vapour across the top of the tank.

2. Materials

(1) All seals such as gaskets, o-rings and joint-rings are to be of non-wicking, i.e. non-fuel absorb- ent, material.

(2) All materials used are to be resistant to deterioration by the fuel for which the system is de-

signed and to other liquids or compounds with which the material can come in contact as in- stalled under normal operating conditions, e.g. grease, lubricating oil, bilge solvents and sea water.

(3) The melting point of materials used for manufacturing of plastic fuel tanks is to be higher than 150 °C.

(4) Copper-based alloys for fittings are acceptable for direct coupling with all tank materials speci-

fied in Table 8.2 except aluminium. Copper-based alloy fittings are allowed for aluminium tanks only if a galvanic barrier is arranged between fitting and tank.

(5) Suitable metallic tank materials and minimum recommended material thicknesses required for

corrosion resistance are given in Table 8.2. Other materials may be equivalent fuel and corrosion resistance.

used if they demonstrate

Table 8.2 Metallic tank materials

3. Petrol fuel tanks

(1) Petrol fuel tanks are not to be integral with the hull.

(2) Petrol fuel tanks are to have all fittings and openings on top, except metallic filling and ven- tilation pipes, which may be connected to the sides or ends of metal petrol fuel tanks, provided that they are welded to the tank and reach above the top of the tank.

(3) Tank drains are not permitted on petrol fuel tanks.

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(4) Petrol fuel tanks are to be subjected to leakage test in accordance with 7.1.2 of ISO 21487

and to be subjected to pressure-impulse test in accordance with 7.2 of ISO 21487.

(5) Non-metallic petrol fuel tanks are to meet the fire test in accordance with 7.3 and 7.4 of ISO 21487.

4. Diesel fuel tanks

(1) Diesel fuel tanks may be constructed independent of or integral with the hull. Care should be taken to avoid penetration of fuel in the hull.

(2) Diesel fuel integral tanks are to be built in accordance with ISO 12215-5.

(3) Diesel fuel tanks may have side inspection openings. Fittings in the bottom, sides or ends are allowed provided that each connection has a shut-off valve directly coupled to the tank. The valve is to be protected or located to prevent physical damage or be of at least 25 mm nominal diameter.

(4) Diesel fuel tank drains, where fitted, are to have a shut-off valve with a plug on the outlet that can only be removed by the use of tools, or the handle of the drain shut-off valve is to be re- movable with the valve in its closed position.

(5) Diesel tanks are to be subjected to leakage test in accordance with 7.1.2 and are to be sub-

jected to pressure/strength test in accordance with 7.1.3 of ISO 21487.

5. Marking to the Tanks

All fuel tanks are to display the following information in contrasting or embossed letters and nu- merals at least 3 mm high:

- manufacturer's name or trademark, city or equivalent, and country;

- year of manufacture (last two digits);

- design capacity, expressed in liters;

- fuel or fuels for which the tank is suitable, in symbols (as specified in ISO 11192) or in words;

- maximum fill-up height above tank top, expressed in meters, and allowable test pressure, ex- pressed in kP; “ISO 21487” marking or label if the tank is a non-metallic petrol fuel tank fire tested in accordance with this International Standard;

- CE marking and identification number of notify authority (if applicable)