2.1 Measures for the prevention of spillages of oil fuel, lubricating oil, hydraulic oil, thermal oil and other flammable liquids

  .1 Tanks used for the storage of oil fuel, lubricating oil, hydraulic oil, thermal oil and other flammable liquids together with their fittings shall be constructed so as to prevent overpressure and spillages due to leakage or overfilling.

  .2 Air pipes from oil fuel tanks shall be led to a safe position on the open deck. They shall not terminate in any place where a risk of ignition is present.

Air pipes from lubricating oil storage tanks may terminate in the machinery space, provided that the open ends are so situated that issuing oil cannot come into contact with electrical equipment or heated surfaces.

  .3 Any overflow pipe shall have a sectional area of at least 1,25 times that of the filling pipe and shall be led to an overflow tank of adequate capacity or to a storage tank having space reserved for overflow purposes.

An alarm device shall be provided to give warning when the oil reaches a predetermined level in the tank, or alternatively, a sight glass shall be provided in the overflow pipe to indicate when any tank is overflowing. Such sight glasses shall be placed on vertical pipes only.

  .4 Safe and efficient means of ascertaining the amount of oil fuel contained in oil fuels tanks shall be provided.

Where sounding pipes are used, they shall not terminate in any space where the risk of ignition of spillage from the sounding pipe might arise. In particular, they shall not terminate in passenger or crew spaces. As a general rule, they shall not terminate in machinery spaces. However, where the Society considers that these latter requirements are impracticable, it may permit termination of sounding pipes from tanks in machinery spaces, on condition that all of the following requirements are met:

• an oil level gauge is provided meeting the requirements of 2.1.1.6.
• the sounding pipes terminate in locations remote from ignition hazards, unless precautions are taken such as the fitting of effective screens to prevent the oil fuel in the case of spillage through the terminations of sounding pipes from coming into contact with a source of ignition;
• the terminations of sounding pipes are fitted with self-closing blanking devices and with a small-diameter self-closing control cock located below the blanking device for the purposes of ascertaining before the blanking device is opened that oil fuel is not present. Provision must be made so as to ensure that any spillage of oil fuel through the control cock involves no ignition hazard;

  .5 Short sounding pipes may be used for tanks other than double bottom tanks without the additional closed level gauge provided an overflow system is fitted.

  .6 Oil level gauges may be used in place of sounding pipes, subject to the following conditions:

• in passenger ships, such gauges shall not require penetration below the top of the tank and their failure or overfilling of the tanks will not permit release of fuel;
• in cargo ships, the failure of such gauges or overfilling of the tank shall not permit release of fuel. The use of cylindrical gauge glasses is prohibited. The Society may permit the use of oil-level gauges with flat glasses and self-closing valves between the gauges and fuel tanks.

 The power supply to all independently-driven oil fuel transfer pumps, oil fuel unit pumps and all other fuel pumps shall be capable of being stopped from a position outside the space that 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.

  .1 Pipes, their joints and fittings shall comply with Unified Requirements P1 and P2.

Short lengths of flexible pipe may be permitted in positions where the Society is satisfied that they are necessary. Such flexible pipes and end attachments shall be of approved fire resisting materials^footnote of adequate strength and shall be constructed to the satisfaction of the Society.

Hose clamps and similar types of attachments for flexible pipes are not permitted.

  .2 Every oil fuel pipe, which, if damaged, would allow oil to escape from a storage, settling or daily service tank situated above the double bottom shall be fitted with a cock or valve directly on the tank, capable of being closed from a safe position outside the space concerned in the event of a fire occurring in the space in which such tanks are situated. In the special case of deep tanks situated in any shaft or pipe tunnel or similar space, valves on the tank shall be fitted, but control in the event of fire may be effected by means of an additional valve on the pipe or pipes outside the tunnel or similar space. If such an additional valve is fitted in the machinery space, it shall be fitted as close as possible to the penetration of the pipe into the machinery space, and it shall be operated locally and from a position outside this space.

  .3 Pipes conveying oil fuel heated above 60°C shall be placed in sight above the platform in well-lighted parts of machinery spaces, and the number of flanged joints shall be kept to a minimum necessary for mounting purposes.

The scantlings of the pipes which convey heated oil fuel, as well as their flanges, shall be suitable for a pressure of at least 14 bar or for the design pressure, whichever is greater.

  .4 The oil fuel injection and return piping for internal combustion engines shall comply with Unified Requirement M17.

Cocks or valves shall be provided for isolating instruments from the main pipes.

Temperature sensors shall be fitted in pockets.

  .5 All valves and cocks forming part of the oil fuel installation shall be capable of being operated from readily accessible positions.

The number of detachable pipe connections shall be limited to those which are necessary for mounting and dismantling purposes.

  .1 Containment provided for areas where frequent leakage may be expected such as oil burners, purifiers, drains and valves under daily service tanks etc. shall be fitted with adequate drainage. Where drain pipes are provided from collected leakages, they shall be led to a suitable oil drain tank not forming part of an overflow system.

  .2 Where boilers are located in machinery spaces on 'tween decks and the boiler rooms are not separated from the machinery space by watertight bulkheads, the 'tween decks shall be provided with coamings at least 200 mm in height. This area may be drained to the bilges.

The drain tank is not to form part of an overflow system.

 Stop valves or cocks shall be fitted on both suction and delivery sides of oil fuel pumps. All oil fuel pumps shall be provided with pressure relief valves on the discharge side so that the discharged oil may be led to the suction side of the pump.

 Pressure relief valves need not be fitted when the system is served only by centrifugal pumps, so designed that the pressure delivered cannot exceed that for which the piping is designed.