Section 1 Artificial Ventilation in the Cargo Area
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 11 Production, Storage and Offloading of Liquefied Gases in Bulk - Chapter 12 Artificial Ventilation in the Cargo Area - Section 1 Artificial Ventilation in the Cargo Area

Section 1 Artificial Ventilation in the Cargo Area

Parent topic: Chapter 12 Artificial Ventilation in the Cargo Area

1.1 Spaces required to be entered during normal cargo handling operations

The requirements of this Chapter replace the requirements SOLAS Regulations 5.2 Restriction on boundary openings .2.6 and 5.4 Ventilation .4.1, as amended.

1.1.1 Electric motor rooms, cargo compressor and pump rooms, spaces containing cargo handling equipment and other enclosed spaces where cargo vapours may accumulate shall be fitted with fixed artificial ventilation systems capable of being controlled from outside such spaces. The ventilation shall be run continuously to prevent the accumulation of toxic and/or flammable vapours, with a means of monitoring acceptable to the Administration to be provided. A warning notice requiring the use of such ventilation prior to entering shall be placed outside the compartment.

1.1.2 Artificial ventilation inlets and outlets shall be arranged to ensure sufficient air movement through the space to avoid accumulation of flammable, toxic or asphixiant vapours, and to ensure a safe working environment.

1.1.3 The ventilation system shall have a capacity of not less than 30 changes of air per hour, based upon the total volume of the space. As an exception, non-hazardous cargo control rooms may have eight changes of air per hour.

1.1.4 Where a space has an opening into an adjacent more hazardous space or area, it shall be maintained at an over-pressure. It may be made into a less hazardous space or non-hazardous space by over-pressure protection in accordance with recognised Standards such as IEC 60092-502:1999 Electrical installations in ships - Part 502: Tankers – Special features. Where the hazard in the adjacent more hazardous space is a potential flammable or explosive gas air mixture, and the space in question is to be classified as a non-hazardous or less hazardous area as per hazardous area classification see Pt 7, Ch 2, 2 Classification of hazardous areas, the adjacent more hazardous space shall be maintained with an underpressure of at least 50 Pa in relation to the space in question, to comply with Pt 7, Ch 2, 6.2 Ventilation of hazardous spaces 6.2.2 .

1.1.5 Ventilation ducts, air intakes and exhaust outlets serving artificial ventilation systems shall be positioned in accordance with recognised Standards.

1.1.6 Ventilation ducts serving hazardous areas shall not be led through accommodation, service and machinery spaces or control stations, except as allowed in Pt 11, Ch 16 Use of Cargo as Fuel.

1.1.7 Electric motors driving fans shall be placed outside the ventilation ducts that may contain flammable vapours. Ventilation fans shall not produce a source of ignition in either the ventilated space or the ventilation system associated with the space. For hazardous areas, ventilation fans and ducts, adjacent to the fans shall comply with Pt 7, Ch 2, 5.1 General 5.1.2 and be of non sparking construction, as defined below:
  1. impellers or housing of non-metallic construction, with due regard being paid to the elimination of static electricity;
  2. impellers and housing of non-ferrous materials;
  3. impellers and housing of austenitic stainless steel; and
  4. ferrous impellers and housing with not less than 13 mm design tip clearance.

Any combination of an aluminium or magnesium alloy fixed or rotating component and a ferrous fixed or rotating component, regardless of tip clearance, is considered a sparking hazard and shall not be used in these places.

1.1.8 Where fans are required by this Chapter, full required ventilation capacity for each space shall be available after failure of any single fan or spare parts shall be provided comprising; a motor, starter spares and complete rotating element, including bearings of each type.

1.1.9 Protection screens of not more than 13 mm square mesh shall be fitted to outside openings of ventilation ducts.

1.1.10 Where spaces are protected by pressurisation the ventilation shall be designed and installed in accordance with recognised Standards.

1.1.11  For Pt 11, Ch 12, 1.1 Spaces required to be entered during normal cargo handling operations 1.1.5 to Pt 11, Ch 12, 1.1 Spaces required to be entered during normal cargo handling operations 1.1.10 reference is made to the recommendation published by the International Electrotechnical Commission: in particular to the publication IEC 60092-502:1999.

1.2 Spaces not normally entered

1.2.1 Enclosed spaces where cargo vapours may accumulate shall be capable of being ventilated to ensure a safe environment when entry into them is necessary. This shall be capable of being achieved without the need for prior entry.

1.2.2  Ventilation systems are to be capable of use prior to entry and during occupation. For permanent installations, the capacity of 8 air changes per hour shall be provided and for portable systems, the capacity of 16 air changes per hour.

Fans or blowers shall be clear of personnel access openings, and shall comply with Pt 11, Ch 12, 1.1 Spaces required to be entered during normal cargo handling operations 1.1.7.

1.2.3  Enclosed spaces in the cargo area used as laboratories, workshops, decontamination cubicles or for domestic purposes are to comply with the requirements of Pt 11, Ch 12, 1.1 Spaces required to be entered during normal cargo handling operations 1.1.1.

1.2.4  Particulars of the type and number of portable fans, their arrangements and means of attachment are to be submitted for consideration in relation to the internal and external arrangements of the space concerned.

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