Chapter 4 - Special Requirements for Products with a Flashpoint Not Exceeding 60C, Toxic Products and Acids
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Chapter 4 - Special Requirements for Products with a Flashpoint Not Exceeding 60C, Toxic Products and Acids

 To ensure that the designs of the vessels are such that the consequences of any release of liquid cargo with severe safety hazards will be minimized, and to provide protection to the vessel and crew from fire, toxic vapour and corrosive substances. The provisions in this chapter are additional to the general provisions of chapter 3 of the present Code.

4.1 General requirements for products with a flashpoint not exceeding 60C, toxic products and acids

4.1.1 Unless expressly provided otherwise, the provisions of this section are applicable to products with a flashpoint not exceeding 60C, toxic products and acids. These provisions are additional to the general provisions of the present Code.

4.1.2 Cargo tanks certified for products or residues of products subject to the provisions of this chapter should be segregated from machinery spaces, propulsion shaft tunnels, solid bulk cargo and underdeck access way if fitted, by means of a cofferdam,footnote void space, cargo pump-room, empty tank or other similar space.

4.1.3 Cargo tanks certified for products subject to the provisions of this chapter need to be separated from the deck plating by cofferdams.

4.1.4 Cargo piping should not pass through any underdeck access way or machinery spaces.

4.1.5 Discharge arrangements for ballast or fresh water sited immediately adjacent to cargo tanks certified for products or residues of products subject to the provisions of this chapter should be outside machinery spaces and accommodation spaces. Filling arrangements may be in the machinery spaces provided that such arrangements ensure filling from main deck level and non-return valves are fitted.

4.1.6 Bilge pumping systems serving spaces where cargoes or residues of cargoes may occur are to be independent from systems serving spaces outside such areas and are to be entirely situated within the area related to cargos subject to this chapter. The bilge system serving these spaces should be operable from outside the cargo area.

4.1.7 In order to guard against the danger of hazardous vapours, due consideration should be given to the location of air intakes and openings into accommodation, passageways, service and machinery spaces and control stations in relation to cargo piping and cargo vent systems as defined in 1.2.7.

4.1.8 All access to cargo tanks, cofferdams, void spaces, cargo pump-room, pump-room, empty tank, or other spaces adjacent to cargo tanks certified for products subject to the provisions of this chapter, should be direct from the open deck and such as to ensure their complete inspection. The dimensions of the accesses should be in accordance with 3.3.2 to 3.3.4.

4.1.9 High walkways should not be located within the cargo area as defined in 1.2.7.3.3.

4.2 Products with a flashpoint not exceeding 60C

4.2.1 The provisions of this section are applicable to products with a flashpoint not exceeding 60C. These provisions are in addition to the general provisions of chapter 3 of the present Code.

4.2.2 Unless they are located at least 7 m away from the deck area as defined in 1.2.7.3, entrances, air inlets and openings to accommodation, service and machinery spaces and control stations should not face the cargo deck area. Doors to spaces not having access to accommodation, service and machinery spaces and control stations, such as cargo control stations and storerooms, may be permitted within such deck area, provided the boundaries of the spaces are insulated to A-60 standard. When arranged within such deck area, windows and sidescuttles facing the deck area should be of a fixed (non-opening) type. Such sidescuttles in the first tier on the main deck should be fitted with inside covers of steel or equivalent material.

4.3 Toxic products

4.3.1 The provisions of this section are applicable to toxic products. These provisions are additional to the general provisions of chapter 3 of the present Code and to the special requirements in section 15.12 of the IBC Code.

4.3.2 Unless they are located at least 15 m away from the deck area as defined in 1.2.7.3, entrances, air inlets and openings to accommodation, service and machinery spaces and control stations should not face the deck area. Doors to spaces not having access to accommodation, service and machinery spaces and control stations, such as cargo control stations and storerooms, may be permitted within such deck area, provided the boundaries of the spaces have equivalent gas tightening to A-60 standard. Wheelhouse doors and wheelhouse windows may be located within the limits specified above so long as they are designed in such a way that a rapid and efficient gas- and vapour-tightening of the wheelhouse can be assured. Windows and sidescuttles facing the deck area and on the sides of the superstructures and deckhouses within the limits specified above should be of the fixed (non-opening) type. Such sidescuttles in the first tier on the main deck should be fitted with inside covers of steel or equivalent material.

4.3.3 For a vessel certified to carry toxic products only subject to the requirements of 15.12.3 and 15.12.4 of the IBC Code, entrances, air inlets and openings to accommodation, service and machinery spaces and control stations may be accepted in bulkheads facing the cargo deck area if they are located outside the deck area as defined in 1.2.7.3.

4.3.4 Cargo tanks certified to carry toxic products should be fitted with fixed tank washing arrangements. Other arrangements allowing cleaning of the tank(s) without the need for personnel to enter during the cleaning process may be fitted, if proper safety equipment is used.

4.3.5 The cargo deck area should be such as to promote natural ventilation and to prevent toxic gas from accumulating in closed or partly closed spaces on deck. A high closed cargo rail in the stern is prohibited. However, if proper natural ventilation can be documented, a higher aft bulwark/cargo rail may be accepted.

4.3.6 Means should be provided to minimize the range of a possible leak in the hose landing area on the main deck. An example of such means is transverse gutter bars on both sides of the hose landing area in way of the loading stations.

4.3.7 The set point of the pressure side of the P/V valves should be set at a minimum 0.6 bar gauge.

4.4 Acids

4.4.1 The provisions of this section are applicable to acids. These provisions are additional to the general provisions of the present Code and to the special requirements in section 15.11 of the IBC Code.

4.4.2 Floors or decks under acid storage tanks and pumps and piping for acid should have a lining or coating of corrosion-resistant material extending up to a minimum height of 500 mm on the bounding bulkheads or coamings. Hatches or other openings in such floors or decks should be raised to a minimum height of 500 mm; however, where the Administration determines that this height is not practicable, a lesser height may be accepted.

4.4.3 Flanges or other detachable pipe connections should be covered by spray shields.

4.4.4 Portable shield covers for connecting the flanges of the loading manifold should be provided. Drip trays of corrosion-resistant material should be provided under loading manifolds for acids.

4.4.5 Spaces for acid storage tanks and acid pumping and piping should be provided with drainage arrangements of corrosion-resistant materials.

4.4.6 Deck spills should be kept away from accommodation and service areas by means of a permanent coaming of suitable height and extension.


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