11.3.7(a) Fuel oil tanks. Sounding pipes from fuel oil tanks may terminate in machinery spaces provided that the following are met:
i) The sounding pipes are to terminate in locations remote from the ignition hazards, or effective precautions, such as shielding, are taken to prevent fuel oil spillage from coming into contact with a source of ignition.
ii) The termination of sounding pipes is fitted with a quick-acting self-closing valve and with a small diameter self-closing test cock or equivalent located below the self-closing valve for the purpose of ascertaining that fuel oil is not present before the valve is opened. Provisions are to be made to prevent spillage of fuel oil through the test cock from creating an ignition hazard.
iii) A level gauge complying with 4-6-4/11.5.1 is fitted for fuel oil service tanks and settling tanks. However, 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. See 4-6-4/13.5.4. The oil level gauge may also be omitted for vessels less than 500 gross tons. 11.3.7(b) Lubricating oil tanks. Sounding pipes from lubricating oil tanks may terminate in machinery spaces provided that the following are met:
i) The sounding pipes are to terminate in locations remote from the ignition hazards, or effective precautions, such as shielding, are taken to prevent oil spillage from coming into contact with a source of ignition.
ii) The termination of sounding pipes is fitted with a quick-acting self-closing gate valve. Alternatively, for lubricating oil tanks that cannot be filled by a pump, the sounding pipes may be fitted with an appropriate means of closure, such as a shut-off valve or a screw cap attached by chain to the pipe.