Section 3 Pump rooms

3.1.1 Where it is intended to install fuel transfer pumps for handling fuel with a flash point less than 60ºC in a separate compartment, the requirements of Vol 2, Pt 7, Ch 4, 3.1 General 3.1.2 to Vol 2, Pt 7, Ch 4, 3.1 General 3.1.5, Vol 2, Pt 7, Ch 4, 3.2 Pump room ventilation and Vol 2, Pt 7, Ch 4, 3.3 Non-sparking fans for hazardous areas are to be complied with.

3.1.2 The pump rooms are to be totally enclosed and are to have no direct communication, through e.g. bilge piping systems and ventilation systems, with machinery spaces.

3.1.3 Pump rooms are to be situated adjacent to the fuel storage tanks and are to be provided with ready means of access from the open deck.

3.1.4 Alarms and safety arrangements are to be provided as indicated in Vol 2, Pt 7, Ch 4, 3.1 General 3.1.5and Table 4.3.1 Alarms. These requirements are applicable to pump rooms where pumps for fuels, such as fuel pumps and stripping pumps are provided and not for pump rooms intended solely for ballast transfer.

3.1.5 A system for continuously monitoring the concentrations of hydrocarbon gases within the pump room is to be fitted in accordance with Vol 2, Pt 9, Ch 11 Gas Detection. Monitoring points are to be located in positions where potentially dangerous concentrations may be readily detected.

3.1.6 Where the flash point of the fuel is not less than 60ºC, the arrangements are to comply with the requirements applicable to machinery spaces, see Vol 2, Pt 1, Ch 3 Requirements for Design, Construction, Installation and Sea Trials of Engineering Systems.

3.2.1 Fuel pump rooms and other closed spaces which contain fuel handling equipment, and to which regular access is required during cargo handling operations, are to be provided with permanent ventilation systems of the mechanical extraction type.

3.2.2 The ventilation system is to be capable of being operated from outside the compartment being ventilated and a notice to be fixed near the entrance stating that no person is to enter the space until the ventilation system has been in operation for at least 15 minutes.

3.2.3 The ventilation systems are to be capable of 20 air changes per hour, based on the gross volume of the pump room or space.

3.2.4 The ventilation ducting is to be arranged to permit extraction from the vicinity of the pump room bilges, immediately above the transverse floor plates or bottom longitudinals. An emergency intake is also to be arranged in the ducting at a height of 2 m above the pump room lower platform and is to be provided with a damper capable of being opened or closed from the weather deck and lower platform level. An arrangement involving a specific ratio of areas of upper emergency and lower main ventilation openings, which can be shown to result in at least the required number of air changes through the lower inlets, can be accepted without the use of dampers. When the lower inlets are sealed off, owing to flooding of the bilges, then at least 75 per cent of the required number of air changes is to be obtainable through the upper inlets. Means are to be provided to ensure the free flow of gases through the lower platform to the duct intakes.

3.2.5 Protection screens of not more than 13 mm square mesh are to be fitted in outside openings of ventilation ducts, and ventilation intakes are to be so arranged as to minimise the possibility of re-cycling hazardous vapours from any ventilation discharge opening. Vent exits are to be arranged to discharge upwards.

3.2.6 The vent exits from pump rooms are to discharge at least 3 m above deck, and from the nearest air intakes or openings to accommodation and enclosed working spaces, and from possible sources of ignition.

3.2.7 The ventilation is to be interlocked to the lighting system (except emergency lighting) such that the pump room lighting may only come on when the ventilation is in operation. Failure of the ventilation system is not to cause the lighting to go out and failure of the lighting system is not to cause loss of the ventilation system.

3.3.1 The air gap between impeller and housing of the fan is to be not less than 0,1 of the impeller shaft bearing diameter or 2 mm whichever is the larger, subject also to compliance with Vol 2, Pt 7, Ch 4, 3.3 Non-sparking fans for hazardous areas 3.3.2.(e). Generally, however, the air gap need be no more than 13 mm.

3.3.2 The following combinations of materials are permissible for the impeller and the housing in way of the impeller:

1. Impellers and/or housings of non-metallic material, due regard being paid to the elimination of static electricity.

2. Impellers and housings of non-ferrous metals.

3. Impellers and housings of austenitic stainless steel.

4. Impellers of aluminium alloys or magnesium alloys and a ferrous housing provided that a ring of suitable thickness of non-ferrous material is fitted in way of the impeller.

5. Any combination of ferrous impellers and housings with not less than 13 mm tip clearance.

6. Any combination of materials for the impeller and housing which are demonstrated as being spark proof by appropriate rubbing tests.

3.3.3 The following combinations of materials for impellers and housing are not considered spark proof and are not permitted:

1. Impellers of an aluminium alloy or magnesium alloy and a ferrous housing, irrespective of tip clearance.

2. Impellers of a ferrous material and housings made of an aluminium alloy, irrespective of tip clearance.

3. Any combination of ferrous impeller and housing with less than 13 mm tip clearance, other than permitted by Vol 2, Pt 7, Ch 4, 3.3 Non-sparking fans for hazardous areas 3.3.2.(c).

3.3.4 Electrostatic charges both in the rotating body and the casing are to be prevented by the use of antistatic materials (i.e. materials having an electrical resistance between 5 x 10⁴ ohms and 10⁸ ohms), or special means are to be provided to avoid dangerous electrical charges on the surface of the material.

3.3.5 Type tests on the complete fan are to be carried out to the Surveyor’s satisfaction.

3.3.6 Protection screens of not more than 13 mm square mesh are to be fitted in the inlet and outlet of ventilation ducts to prevent the entry of objects into the fan housing.

3.3.7 The installation of the ventilation units on board is to be such as to ensure the safe bonding to the hull of the units themselves.