IMO IBC code 1998

Chemicals for Young Coots Compiled by Nicholas H Moore Chemicals for Young Coots Foreword On 17 June 1983 the Maritime Safety Committee (MSC) adopted, by resolution MSC.4(48), the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code) Under the provisions of chapter VII of the International Convention for the Safety of Life at Sea, 1974 (SOLAS 74), as amended in 1983, chemical tankers constructed on or after July 1986 must comply with the provisions of the Code On December 1985, by resolution MEPC.19(22), the IBC Code was extended by the Marine Environment Protection Committee (MEPC) to cover marine pollution aspects for the implementation of Annex II of the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto (MARPOL 73/78) Under the provisions of regulation 13 of Annex II of MARPOL 73/78, chemical tankers constructed on or after July 1986 must comply with the provisions of the Code The MSC then formally adopted the same amendments as those adopted by the MEPC by resolution MSC.10(54), under article VIII(b) of SOLAS 74, so that the IBC Code remains identical for the purposes of both MARPOL 73/78 and SOLAS 74 The two Committees subsequently established appropriate procedures for amending the IBC Code (MEPC.25J20, annex 7) to ensure that the Code remains identical at all times under the mandatory requirements of the two Conventions Under MARPOL 73/78 chemical tankers constructed before July 1986 must comply with the provisions of the Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (BCH Code) Under SOLAS 74 the BCH Code remains as a recommendation The BCH Code is issued as a separate publication The Index of Dangerous Chemicals Carried in Bulk - a supplement to the IBC and BCH Codes, contained an index of all chemicals referred to in the BCH and IBC Codes which provided the various names known for a particular chemical This index has now been updated and incorporated into the present publication Previously, annexes II and III of MARPOL 73 f 78 contained lists of products which were reproduced in chapters 17 and 18 of the IBC Code as well as chapters VI and VII of pre-1993 editions of the BCH Code However, since 1993, the fists of products in chapters VI and VII of the BCH Code have been replaced by reference to the IBC Code In addition, the lists of products in appendices II and III of annex II to the 1997 consolidated edition of MARPOL 73/78 have also been replaced by references to the IBC Code As a result, the IBC Code is now the definitive source of names for products subject to appendices II and III of Annex If of MARPOL 73/78 Reference is also made to the MEPC.2/Circs, issued annually in December; these contain, inter alia, details of products that have been the subject of Tripartite Agreements and are, in effect, a supplement to the IBC Code Annex of these circulars includes products that are expected to become new or amended entries to the IBC Code A future amendment, shown in the circular, serves as prior notice of the carriage conditions which will only apply to that product when the next set of amendments enter into force A number of other documents closely related to the IBC Code are annexed to this publication The MSC and MEPC agreed that, at their spring 1990 sessions, they would adopt amendments to the BCN Code to introduce the harmonized system of survey and certification Under the provisions of these proposed amendments, they will enter into force when the 1988 SOLAS Protocol, which contains corresponding provisions, enters into force, at which time section 1.5 and the model form of the Certificate of Fitness will be replaced Compiled by Nicholas H Moore Chemicals for Young Coots Contents International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk Preamble CHAPTER -GENERAL 1.1 Application 1.2 Hazards 1.3 Definitions 1.4 Equivalents 1.5 Surveys and certification CHAPTER - SHIP SURVIVAL CAPABILITY AND LOCATION OF CARGO TANKS 2.1 General 2.2 Freeboard and intact stability 2.3 Shipside discharges below the freeboard deck 2.4 Conditions of loading 2.5 Damage assumptions 2.6 Location of cargo tanks 2.7 Flooding assumptions 2.8 Standard of damage 2.9 Survival requirements CHAPTER - SHIP ARRANGEMENTS 3.1 Cargo segregation 3.2 Accommodation, service and machinery spaces and control stations 3.3 Cargo pump-rooms 3.4 Access to spaces in the cargo area 3.5 Bilge and ballast arrangements 3.6 Pump and pipeline identification 3.7 Bow or stern loading and unloading arrangements CHAPTER - CARGO CONTAINMENT 4.1 Definitions 4.2 Tank type requirements for individual products CHAPTER - CARGO TRANSFER 5.1 Piping scantlings 5.2 Piping fabrication and joining details 5.3 Flange connections 5.4 Test requirements for piping 5.5 Piping arrangements 5.6 Cargo-transfer control systems 5.7 Ship's cargo hoses Compiled by Nicholas H Moore Chemicals for Young Coots CHAPTER - MATERIALS OF CONSTRUCTION 6.1 General 6.2 Special requirements for materials CHAPTER - CARGO TEMPERATURE CONTROL 7.1 General 7.2 Additional requirements CHAPTER - CARGO-TANK VENTING AND GAS-FREEING ARRANGEMENTS 8.1 Application 8.2 Cargo-tank venting 8.3 Types of tank venting systems 8.4 Venting requirements for individual products 8.5 Cargo-tank gas-freeing CHAPTER - ENVIRONMENTAL CONTROL 9.1 General 9.2 Environmental control requirements for individual products CHAPTER 10 - ELECTRICAL INSTALLATIONS 10.1 General 10.2 Hazardous locations and types of equipment and wiring 10.3 Bonding 10.4 Electrical requirements for individual products CHAPTER 11 - FIRE PROTECTION AND FIRE EXTINCTION 11.1 Application 11.2 Cargo pump-rooms 11.3 Cargo area 11.4 Special requirements CHAPTER 12 - MECHANICAL VENTILATION IN THE CARGO AREA 12.1 Spaces normally entered during cargo-handling operations 12.2 Pump-rooms and other enclosed spaces normally entered 12.3 Spaces not normally entered CHAPTER 13 - INSTRUMENTATION 13.1 Gauging 13.2 Vapour detection Compiled by Nicholas H Moore Chemicals for Young Coots CHAPTER 14 - PERSONNEL PROTECTION 14.1 Protective equipment 14.2 Safety equipment CHAPTER 15 - SPECIAL REQUIREMENTS 15.1 Acetone cyanohydrin and lactonitrile solution (80% or less) 15.2 Ammonium nitrate solution (93% or less) 15.3 Carbon disulphide 15.4 Diethyl ether 15.5 Hydrogen peroxide solutions 15.6 Motor fuel anti-knock compounds (containing lead alkyls) 15.7 Phosphorus, yellow or white 15.8 Propylene oxide and mixtures of ethylene oxide/ propylene oxide with an ethylene oxide content of not more than 30% by weight 15.9 Sodium chlorate solution (50% or less) 15.10 Sulphur (molten) 15.11 Acids 15.12 Toxic products 15.13 Cargoes protected by additives 15.14 Cargoes with a vapour pressure greater than 1.013 bar absolute at 37.8°C 15.15 Cargoes with low ignition temperature and wide flammability range [Deleted] 15.16 Cargo contamination 15.17 Increased ventilation requirements 15.18 Special cargo pump-room requirements 15.19 Overflow control 15.20 Alkyl (C7-C9) nitrates, all isomers 15.21 Temperature sensors CHAPTER 16 - OPERATIONAL REQUIREMENTS 16.1 Maximum allowable quantity of cargo per tank 16.2 Cargo information 16.3 Personnel training 16.4 Opening of and entry into cargo tanks 16.5 Stowage of cargo samples 16.6 Cargoes not to be exposed to excessive heat 16.7 Additional operational requirements CHAPTER 16A ENVIRONMENT - ADDITIONAL MEASURES FOR THE PROTECTION 16A.1 General 16A.2 Condition of carriage 16A.3 Procedures and Arrangements Manual CHAPTER 17 - SUMMARY OF MINIMUM REQUIREMENTS CHAPTER 18 – LIST OF CHEMICALS TO WHICH THE CODE DOES NOT APPLY Compiled by Nicholas H Moore OF THE MARINE Chemicals for Young Coots CHAPTER 19 - REQUIREMENTS FOR SHIPS ENGAGED IN THE INCINERATION AT SEA OF LIQUID CHEMICAL WASTE 19.1 General 19.2 Ship survival capability and location of cargo tanks 19.3 Ship arrangements 19.4 Cargo containment and incinerator standards 19.5 Cargo transfer 19.6 Materials of construction 19.7 Tank vent systems 19.8 Cargo-tank environmental control 19.9 Electrical installation 19.10 Fire protection and fire extinguishing 19.11 Mechanical ventilation in the cargo area and in the incinerator location 19.12 Instrumentation and overflow control 19.13 Personnel protection CHAPTER 20 - TRANSPORT OF LIQUID CHEMICAL WASTES 20.1 Preamble 20.2 Definitions 20.3 Applicability 20.4 Permitted shipments 20.5 Documentation 20.6 Classification of liquid chemical wastes 20.7 Carriage and handling of liquid chemical wastes APPENDIX Model form of International Certificate of Fitness for the Carriage of Dangerous Chemicals in Bulk Index of dangerous chemicals carried in bulk Relevant decisions of the MSC and MEPC Criteria for hazard evaluation of bulk chemicals Guidelines for the uniform application of the survival requirements of the Bulk Chemical Code and the Gas Carrier Code Revised standards for the design, testing and locating of devices to prevent the passage of flame into cargo tanks in tankers Revised factors to be taken into consideration when designing cargo tank venting and gas-freeing arrangements Calculation of the capacity of foam systems for chemical tankers Procedures for inspection, cleaning, passivation and loading of tanks for the carriage of hydrogen peroxide solutions 8-60%, which have contained other cargoes, or for the carriage of other cargoes after the carriage of hydrogen peroxide Compiled by Nicholas H Moore Chemicals for Young Coots IBC Code Preamble The purpose of this Code is to provide an international standard for the safe carriage by sea in bulk of dangerous and noxious liquid chemicals listed in chapter 17 of the Code by prescribing the design and construction standards of ships, regardless of tonnage, involved in such carriage and the equipment they should carry so as to minimize the risk to the ship, to its crew and to the environment, having regard to the nature of the products involved The basic philosophy is to assign to each chemical tanker one of the ship types according to the degree of the hazards of the products carried by such ship Each of the products may have one or more hazard properties, which include flammability, toxicity, corrosivity and reactivity, as well as the hazard they may present to the environment if accidentally released Throughout the development of the Code it was recognized that it must be based upon sound naval architectural and engineering principles and the best understanding available as to the hazards of the various products covered; furthermore that chemical tanker design technology is not only a complex technology but is rapidly evolving and that the Code should not remain static Therefore the Organization will periodically review the Code, taking into account both experience and technical development Amendments to the Code involving requirements for new products and their conditions of carriage will be circulated as recommendations, on an interim basis, when adopted by the Maritime Safety Committee (MSC) and the Marine Environment Protection Committee (MEPC) of the Organization, in accordance with the provisions of article VIII of the International Convention for the Safety of Life at Sea, 1974 (SOLAS 74), and article 16 of the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol relating thereto (MARPOL 73/78), respectively, pending the entry into force of these amendments The Code primarily deals with ship design and equipment In order to ensure the safe transport of the products, the total system must, however, be appraised Other important facets of the safe transport of the products, such as training, operation, traffic control and handling in port, are being or will be examined further by the Organization The development of the Code has been greatly assisted by relevant work of the International Association of Classification Societies (IACS) and of the International Electrotechnical Commission (IEC) Chapter 16 of the Code, dealing with operational requirements of chemical tankers, highlights the regulations in other chapters that are operational in nature and mentions those other important safety features that are peculiar to chemical tanker operation The layout of the Code is in line with the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code), adopted by the Maritime Safety Committee at its forty-eighth session Gas carriers may also carry in bulk liquid chemicals covered by this Code, as prescribed in the IGC Code The 1998 edition of the Code is based on the original text as adopted by MSC resolution MSC.4(48) In response to resolution 15 of the International Conference on Marine Pollution, 1973, the MEPC, at its twenty-second session, adopted, by resolution MEPC.19(22), the IBC Code extended to cover marine pollution prevention aspects for the implementation of Annex 11 to MARPOL 73/78 10 Subsequent to this, the 1998 edition of the Code includes amendments adopted by the following resolutions: Compiled by Nicholas H Moore Chemicals for Young Coots Resolution MSC.10(54) MSC.14(57) MEPC:.32(27) MSC.28(61) MEPC.55(33) MSC.50(66) MEPC.69(38) MSC.58(67) MEPC.73(39) Adoption 29 April 1987 11 April 1984 17 March 1989 11 December 1992 30 October 1992 June 1996 10 July 1996 December 1996 10 March 1997 Deemed acceptance 29 April 1988 12 April 1990 12 April 1990 January 1994 January 1994 January 1998 January 1998 January 1998 10 January 1998 Entry into force 30 October 1988 13 October 1990 13 October 1990 July 1994 July 1994 July 1998 July 1998 July 1998 10 July 1998 * * Note: Parties invited to implement on July 1998 11 As from the date of entry into force of the 1983 amendments to SOLAS 74 (i.e July 1986) and the date of implementation of Annex II of MARPOL 73/78, this Code became subject to mandatory requirements under these Conventions Amendments to the Code, whether from the point of view of safety or of marine pollution, must therefore be adopted and brought into force in accordance with the procedures laid down in article VIII of SOLAS 74 and article 16 of MARPOL 73/78 respectively Compiled by Nicholas H Moore Chemicals for Young Coots Chapter - General 1.1 Application 1.1.1 The Code applies to ships regardless of size, including those of less than 500 tons gross tonnage, engaged in the carriage of bulk cargoes of dangerous or noxious liquid chemical substances, other than petroleum or similar flammable products as follows: products having significant fire hazards in excess of those of petroleum products and similar flammable products; products having significant hazards in addition to or other than flammability Products that have been reviewed and determined not to present safety and pollution hazards to such an extent as to warrant the application of the Code are found in chapter 18 1.1.2 Liquids covered by the Code are those having a vapour pressure not exceeding 2.8 bar absolute at a temperature of 37.8°C 1.1.2A For the purpose of the 1974 SOLAS Convention, the Code does not apply to ships which are engaged in the carriage of products included in chapter 17 solely on the basis of their pollution characteristics and identified as such by an entry of "P" only in column d 1.1.2B For the purposes of MARPOL 73/78, the Code applies only to chemical tankers, as defined in regulation 1(1) of Annex II thereof, which are engaged in the carriage of noxious liquid substances falling into category A, B or C and identified as such by an entry of "A", "B" or "C" in column c 1.1.3 For a product proposed for carriage in bulk, but not listed in chapter 17 or 18, the Administration and port Administrations involved in such carriage should prescribe the preliminary suitable conditions for the carriage, having regard to the criteria for hazard evaluation of bulk chemicals The Organization should be notified of the conditions for consideration for inclusion of the product in the Code For the evaluation of the pollution hazard of such a product and assignment of its pollution category, the procedure specified in regulation 3(4) of Annex II of MARPOL 73/78 must be followed 1.1.4 Unless expressly provided otherwise, the Code applies to ships the keels of which are laid or which are at a stage at which: construction identifiable with the ship begins; and assembly has commenced comprising at least 50 tonnes or % of the estimated mass of all structural material, whichever is less; on or after July 1986 1.1.5 A ship, irrespective of the date of construction, which is converted to a chemical tanker on or after July 1986 should be treated as a chemical tanker constructed on the date on which such conversion commences This conversion provision does not apply to the modification of a ship referred to in regulation 1(12) of Annex II of MARPOL 73/78 1.1.6 Where reference is made in the Code to a paragraph, all the provisions of the subparagraphs of that designation should apply Compiled by Nicholas H Moore Chemicals for Young Coots 1.2 Hazards Hazards of products covered by the Code include: 1.2.1 Fire hazard, defined by flashpoint, boiling point, flammability limits and autoignition temperature of the chemical 1.2.2 Health hazard, defined by: irritant or toxic effect on the skin or on the mucous membranes of the eyes, nose, throat and lungs in the gas or vapour state combined with vapour pressure; or irritational effects on the skin in the liquid state; or toxic effect, taking into account values of LD50 (oral): a dose which is lethal to 50% of the test subjects when administered orally; LD50 (skin): a dose which is lethal to 50% of the test subjects when administered to the skin; LC50: the concentration which is lethal by inhalation to 50% of the test subjects 1.2.3 Water pollution hazard, defined by human toxicity, water solubility, volatility, odour or taste, and relative density 1.2.4 Air pollution hazard, defined by: emergency exposure limit (E.E.L.) or LC50; vapour pressure; solubility in water; relative density of liquid; vapour density 1.2.5 Reactivity hazard, defined by reactivity with: other products; or water; or the product itself (including polymerization) 1.2.6 Marine pollution hazard, as defined by: bioaccumulation with attendant risk to aquatic life or human health or causing tainting to seafood; damage to living resources; hazard to human health; and reduction of amenities Compiled by Nicholas H Moore Chemicals for Young Coots 3.3.2 A flow condition test shall be carried out with high-velocity vents using compressed air or gas at agreed flow rates The following shall be recorded: The flow rate Where air or a gas other than vapours of cargoes with which the vent is to be used is employed in the test, the flow rates achieved shall be corrected to reflect the vapour density of such cargoes .2 The pressure before the vent opens The pressure in the test tank on which the device is located shall not rise at a rate greater than 0.01 N/mm2/min .3 The pressure at which the vent opens .4 The pressure at which the vent closes .5 The efflux velocity at the outlet, which shall not be less than 30 m/s at any time when the valve is open 3.3.3 The following fire safety tests shall be conducted using a mixture of gasoline vapour and air or technical hexane vapour and air which produces the most easily ignitable mixture at the point of ignition This mixture shall he ignited with the aid of a permanent pilot flame or a spark igniter at the outlet: Flashback tests, in which propane may be used instead of gasoline or hexane, shall be carried out with the vent in the upright position and then inclined at 10° from the vertical For some vent designs further tests with the vent inclined in more than one direction may be necessary In each of these tests the flow shall be reduced until the vent closes and the flame is extinguished, and each shall be carried out at least 50 times The vacuum side of combined valves shall be tested in accordance with 3.2.2 with the vacuum valve maintained in the open position for the duration of this test, in order to test the efficiency of the device which must be fitted .2 An endurance burning test, as described in 3.2.3, shall be carried out Following this test, the main flame shall be extinguished and then, with the pilot flame burning or the spark igniter discharging, small quantities of the most easily ignitable mixture shall be allowed to escape for a period of 10 minutes, during which time flashback shall not occur For the purposes of this test the soft seals or seats shall be removed 3.4 Test rig and test procedures for detonation flame arresters located in-line 3.4.1 A flame arrester shall be installed at one end of a pipe of suitable length and of the same diameter as the flange of the flame arrester On the exposed flange, a plastic bag * shall be affixed The pipe shall be tilled with the most easily ignitable mixture of propane and air, which shall then be ignited The velocity of the flame near the flame arrester shall be measured and shall have a value of that for stable detonations * The dimensions shall be at least 4m circumference, 4m length and a material wall thickness of 0.05 mm 3.4.2 Three detonation tests shall be conducted and no flashback shall occur through the device and no part of the flame arrester shall be damaged or show permanent deformation 3.4.3 Other test rigs may be used provided the tests are achieved to the satisfaction of the Administration A drawing of the test rig is shown in appendix 3.5 Operational test procedures 3.5.1 A corrosion test shall be carried out In this test a complete device, including a section of the pipe to which it is fitted, shall be exposed to a 20% sodium chloride solution spray at a temperature of 25°C: for a period of 240 hours and allowed to dry for 48 hours An equivalent test may be used to the satisfaction of Compiled by Nicholas H Moore Chemicals for Young Coots the Administration Following this test, all movable parts shall operate properly and there shall be no corrosion deposits which cannot be washed off 3.5.2 A hydraulic pressure test shall be carried out in the casing or housing of a simple device, in accordance with 2.2.1 MISCELLANEOUS 4.1 Marking of device Each device shall be permanently marked, or have a permanently fixed tag made of stainless steel or other corrosion-resistant material, to indicate: manufacturer's name or trade mark; style, type, model or other manufacturer's designation for the device; size of the outlet for which the device is approved; approved location for installation, including maximum or minimum length of pipe, if any, between the device and the atmosphere; direction of flow through the device; indication of the test laboratory and report number; and compliance with the requirements of MSC,/Circ 373/Rev 4.2 Laboratory report 4.2.1 The laboratory report shall include: detailed drawings of the device; types of tests conducted Where in-line devices are tested, this information should include the maximum pressures and velocities observed in the test; specific advice on approved attachments; types of cargo for which the device is approved; drawings of the test rig; in the case of a high-velocity vent, the pressures at which the device opens and closes in the efflux velocity; and all the information marked on the device in 4.1 4.3 Manufacturer's instruction manual 4.3.1 The manufacturer shall supply a copy of the instruction manual, which shall kept on board the tanker and which shall include: installation instructions; Compiled by Nicholas H Moore Chemicals for Young Coots operating instructions; maintenance requirements, including cleaning (see 2.3.3); copy of the laboratory report referred to in 4.2; and flow test data, including flow rates under both positive and negative pressures, operating sensitivity, flow resistance and velocity Appendix Proposed amendments to regulation II-2/59 [see Note below] Cargo tank purging and/or gas-freeing * Arrangements for purging and/or gas-freeing shall be such as to minimize the hazards due to the dispersal of flammable vapours in the atmosphere and to flammable mixtures in a cargo tank Accordingly: When the ship is provided with an inert gas system, the cargo tanks shall first be purged in accordance with the provisions of regulation 62.13 until the concentration of hydrocarbon vapours in the cargo tanks has been reduced to less than 2% by volume Thereafter, gas-freeing may take place at the cargo tank deck level .2 When the ship is not provided with an inert gas system, the operation shall be such that the flammable vapour is discharged initially: 2.1 through the vent outlets as specified in paragraph 1.9; or 2.2 through outlets at least m above the cargo tank deck level with a vertical efflux velocity of at least 30 m/s maintained during the gas-freeing operation; or 2.3 through outlets at least m above the cargo tank deck level with a vertical efflux velocity of at least 20 m/s and which are protected by suitable devices to prevent the passage of flame When the flammable vapour concentration at the outlet has been reduced to 30% of the lower flammable limit, gas-freeing may thereafter be continued at cargo tank deck level * Refer to the Revised standards for the design, testing and locating of devices to prevent the passage of flame into cargo tanks in tankers (MSC/Circ 373/Rev 1) and to Revised factors to be taken into consideration when designing cargo tank venting and gas freeing arrangements (MSC/Circ 450/Rev 1) Note: This amended text was adopted by resolution MSC.13(57) on 11 April 1989 Compiled by Nicholas H Moore Chemicals for Young Coots Compiled by Nicholas H Moore Chemicals for Young Coots Compiled by Nicholas H Moore Chemicals for Young Coots Compiled by Nicholas H Moore Chemicals for Young Coots Compiled by Nicholas H Moore Chemicals for Young Coots Revised factors to be taken into consideration when designing cargo tank venting and gas-freeing arrangements The amendments to the International Convention for the Safety of Life at Sea, 1974 (SOLAS 1974), include requirements for fire safety measures for tankers in regulations II-2/59 and 62, and the IBC and IGC Codes These amendments contain arrangements for venting, inerting, purging, gas-freeing and ventilation The Sub-Committee on Fire Protection has considered problems associated with the design of cargo tank venting and gas-freeing arrangements and the Maritime Safety Committee has approved the main factors to be considered for the design of the arrangements in above as follows: Maximum loading/discharge rate: the venting system should be designed to take into consideration the maximum permissible loading/discharge rate for each cargo tank and in the case of a combined venting system, for each group of tanks These loading and discharge rates should also be used for the design of the inert gas system, regulation 11-2/62.3.1 .2 Gas evolution: regulation II-2/59.1.9.5 requires at least 25% to be added to the maximum loading rate to account for the increased volume due to gas evolution from the cargo A higher gas evolution factor may be considered for highly volatile cargoes .3 Pressure loss across devices: data relating to pressure loss across devices to prevent the passage of flame, approved in accordance with MSC/Circ 373 and referred to in regulation II2/54.1.5, are to be considered in the design of the venting system Fouling of devices should be taken into account .4 Pressure loss in the venting system: pressure loss calculations of systems including pipes, valves, bends, fittings, etc., should be made to ensure that the pressure inside the cargo tanks does not exceed the pressure these tanks are designed to withstand, taking into consideration and above In the case where a combined venting system is used in association with loading of cargo tanks simultaneously, the combined effect of vapour pressure generated in the tanks and venting system should be considered .5 Pressure at which the vents open: the initial opening pressure of the vent valves should be considered in selecting the appropriate valves for the venting system .6 Density of the gaseous mixture: the maximum density of the gaseous mixtures likely to be encountered in the cargo tanks, having regard to the types of cargo intended to be carried and their temperature, is to be considered .7 Design to prevent liquid overfill: where overflow control systems are fitted, consideration is to be given to the dynamic condition during loading .8 Location of vent outlets: horizontal and vertical distances of the vent outlets are to be in accordance with regulation II-2/59 .9 Types of venting systems: due regard is to be given to cargo segregation when considering a venting system or inert gas system common to more than one tank Where the inert gas main is designed for venting of cargo tanks, additional means for venting of these tanks are to be in accordance with regulation II-2/62.11.3 .10 Vent draining arrangements: the draining arrangements for venting systems are to be designed in accordance with regulation II-2/59.1.4 Compiled by Nicholas H Moore Chemicals for Young Coots 11 Gas-freeing: in designing a gas-freeing system in conformity with proposed regulation II2/59.2.2.2 and 59.2.2.3 (see annex*) in order to achieve the required exit velocities, the following should be considered: the flow characteristics of the fans to be used; the pressure losses created by the design of a particular tank's inlets and outlets; the pressure achievable in the tan driving medium (e.g water or compressed air); the densities of the cargo vapour/air mixtures for the range of cargoes to be carried * The annex has not been included Its text is identical with appendix of MSC/Circ 373/Rev Repairs and renewal of the venting system should conform to the original design parameters Factors in the above paragraphs are to be taken into consideration when modifications are carried out to the venting system The master is to be provided with a manual containing information relating to the maximum loading and unloading rates for each tank or group of tanks established during the design of the venting system, as per paragraph above Data referred to in paragraph 4.3 of MSC/Circ 373/Rev should be taken into consideration when renewing devices referred to in the above circular Compiled by Nicholas H Moore Chemicals for Young Coots Calculation of the capacity of foam systems for chemical tankers * * This is based on MSC/Circ 314, Paragraph numbers have been altered from those of the BCH Code (for which the circular was developed) to refer to appropriate paragraphs of the IBC Code In section 11.3 of the IBC Code concerning fire-extinguishing arrangements for cargo tank areas the foam supply has to be determined in accordance with paragraphs 11.3.5 to 11.3.7 In order to provide for a correct interpretation of the requirements the Sub-Committee on Fire Protection agreed on the following example for a calculation of foam system for a chemical tanker of 10,000 tonnes deadweight The Maritime Safety Committee at its forty-fourth session agreed that this example be followed when calculating the capacity of foam systems for chemical tankers Example of foam system calculation for chemical tanker of 10,000 dwt Ship particulars Beam Length of cargo area Length of largest cargo tank = 14.5 m = 56 m =9m Cargo deck area = 14.5 m x 56 m = 812 m2 Horizontal sectional area of single largest tank = 14.5 m x m = 130.5 m2 Note: for the purpose of this illustration, a single tank encompasses the entire beam of the ship) Proposed monitor spacing =9m Area protected by largest monitor = m x 14.5 m = 130.5 m2 Calculations Determination of foam supply rate: 11.3.5 The largest of: 11.3.5.1 - the foam supply rate based upon the entire cargo deck area l/m2/min x 812 m2 = 1,624 l/min 11.3.5.2 - the foam supply rate based upon the horizontal sectional area of the single largest tank Compiled by Nicholas H Moore Chemicals for Young Coots 11.3.5.3 20 l/m2/min x 130.5 m2 = 2,610 l/min - the foam supply rate based upon the area protected by the largest monitor 10 l/m2/min x 130.5 m2 = *1,305 l/min (*Shall not be less than 1,250 l/min) The foam supply rate is therefore 2,610 l/min, which is the largest of the three above calculated rates Determination of the required quantity of foam concentrate: 11.3.6 - 2,610 l/min is the foam supply rate from regulation 3.14.5 This flow rate for thirty minutes will require 30 x 2,610 l/min = 78,300 litres of foam-water solution If a 5% foam concentrate is used, then 5% of the 78,300 litres must be foam concentrate, or 0.05 x 78,300 = 3,915 litres Determination of the minimum monitor capacity: 11.3.7 - Each monitor must supply at least: (a) 50% of the required foam rate; or (b) 10 l/m2/min for the area it protects; or (c) 1,250 l/min, whichever is greater 50% of the foam supply rate = 2,610 l/min x 0.5 = 1,305 l/min 10 l/m2/min times the area the monitor protects = 130.5 m2 x 10 l/m2/min = 1,305 l/min The minimum monitor capacity is therefore 1,305 l/min Designer wishes to increase monitor spacing to 15 metres between monitors Recalculate required foam supply: 11.3.5.1 - same as before - 1,624 l/min 11.3.5.2 - same as before - 2,610 l/min 11.3.5.3 - larger area covered by monitor is 15m x 14.5m=217.5m2 10 l/m2/min x 217.5 m2 = 2,175 l/min The required foam rate therefore remains 2,610 litres per minute Recalculate required foam concentrate supply: 11.3.6 The minimum foam supply rate has not changed; therefore 3,915 litres of foam concentrate are still required Compiled by Nicholas H Moore Chemicals for Young Coots Recalculate minimum monitor capacity: 11.3.7 - 50% of foam supply rate 2,610 l/min x 0.5 = 1,305 l/min 10 I/m2/min of area protected by monitor = 10 l/m2/min x 217.5 m2 = 2,175 l/min The new minimum monitor capacity is therefore 2,175 l/min Compiled by Nicholas H Moore Chemicals for Young Coots Procedures for inspection, cleaning, passivation and loading of tanks for the carriage of hydrogen peroxide solutions 8-60%, which have contained other cargoes, or for the carriage of other cargoes after the carriage of hydrogen peroxide * * These procedures were originally published as the annex to MSC/Circ.394 Tanks having contained cargoes other than hydrogen peroxide should be inspected, cleaned and passivated before re-use for the transport of hydrogen peroxide solutions The procedures for inspection and cleaning, as given in paragraphs 1.1 to 1.7 below, apply to both stainless steel and pure aluminium tanks (see paragraph 4.20.16 of the BCH Code and paragraph 15.5.15 of the IBC Code) Procedures for passivation are given in paragraph 1.8 for stainless steel and 1.9 for aluminium Unless otherwise specified, all steps apply to the tanks and to all associated equipment having been in contact with the other cargo 1.1 After unloading the previous cargo the tank should be rendered safe and inspected for any residues, scale and rust 1.2 Tanks and associated equipment should be washed with clean filtered water The water to be used should at least have the quality of potable water with a low chlorine content 1.3 Trace residues and vapours of the previous cargo should be removed by steaming of tank and equipment 1.4 Tank and equipment are washed again with clean water (quality as above) and dried, using filtered, oil-free air 1.5 The atmosphere in the tank should be sampled and investigated for the presence of organic vapours and oxygen concentration 1.6 The tank should be checked again by visual inspection for residues of the previous cargo, scale and rust as well as for any smell of the previous cargo 1.7 If inspection or measurements indicate the presence of residues of the previous cargo or its vapours, steps 1.2 to 1.4 should be repeated 1.8 Tank and equipment made from stainless steel which have contained other cargoes than hydrogen peroxide or which have been under repair should be cleaned and passivated, regardless of any previous passivation, according to the following procedure: New welds and other repaired parts should be cleaned and finished using stainless steel wire brush, chisel, sandpaper or buff Rough surfaces should be given a smooth finish A final polishing is necessary .2 Fatty and oily residues should be removed by the use of appropriate organic solvents or detergent solutions in water The use of chlorine-containing compounds should be avoided as they can seriously interfere with passivation .3 The residues of the degreasing agent should be removed, followed by a washing with water .4 In the next step, scale and rust should be removed by the application of acid (e.g a mixture of nitric and hydrofluoric acids), followed again by a washing with clean water .5 All the metal surfaces which can come into contact with hydrogen peroxide should be passivated by the application of nitric acid of a concentration between 10 and 35% by weight The Compiled by Nicholas H Moore Chemicals for Young Coots nitric acid must be free from heavy metals, other oxidizing agents or hydrogen fluoride The passivation process should continue for to 24 hours, depending upon the concentration of acid, the ambient temperature and other factors During this time a continuous contact between the surfaces to be passivated and the nitric acid should be ensured In the case of large surfaces this may be achieved by recirculating the acid Hydrogen gas may be evolved in the passivation process, leading to the presence of an explosive atmosphere in the tanks Therefore, appropriate measures must be taken to avoid the build-up or the ignition of such an atmosphere .6 After passivation the surfaces should be thoroughly washed with clean filtered water The washing process should be repeated until the effluent water has the same pH value as the incoming water .7 Surfaces treated according to the above steps may cause some decomposition when coming into contact with hydrogen peroxide for the first time This decomposition will cease after a short time (usually within two or three days) Therefore an additional flushing with hydrogen peroxide for a period of at least two days is recommended .8 Only degreasing agents and acid cleaning agents which have been recommended for this purpose by the manufacturer of the hydrogen peroxide should be used in the process 1.9 Tanks and equipment made from aluminium and which have contained cargoes other than hydrogen peroxide, or which have been under repair, should be cleaned and passivated The following is an example of a recommended procedure: The tank should be washed with a solution of a sulphonated detergent in hot water, followed by a washing with water .2 The surface should then be treated for 15 to 20 minutes with a solution of sodium hydroxide of a concentration of 7% by weight or treated for a longer period with a less concentrated solution (e.g for 12 hours with 0.4 to 0.5% sodium hydroxide) To prevent excessive corrosion at the bottom of the tank when treating with more concentrated solutions of sodium hydroxide, water should be added continuously to dilute the sodium hydroxide solution which collects there .3 The tank should be thoroughly washed with clean, filtered water As soon as possible after washing, the surface should be passivated by the application of nitric acid of a concentration between 30 and 35% by weight The passivation process should continue for 16 to 24 hours During this time a continuous contact between the surfaces to be passivated and the nitric acid should be ensured .4 After passivation the surfaces should be thoroughly washed with clean, filtered water The washing process should be repeated until the effluent water has the same pH value as the incoming water .5 A visual inspection should be made to ensure that all surfaces have been treated It is recommended that an additional flushing is carried out for a minimum of 24 hours with dilute hydrogen peroxide solution of a concentration approximately 3% by weight 1.10 The concentration and stability of the hydrogen peroxide solution to be loaded should be determined 1.11 The hydrogen peroxide is loaded under intermittent visual supervision of the interior of the tank from an appropriate opening 1.12 If substantial bubbling is observed which does not disappear within 15 minutes after the completion of loading, the contents of the tank should be unloaded and disposed of in an environmentally safe manner The tank and equipment should then be repassivated as described above Compiled by Nicholas H Moore Chemicals for Young Coots 1.13 The concentration and stability of the hydrogen peroxide solution should be determined again If the same values are obtained within the limits of error as in step 1.9, the tank is considered to be properly passivated and the cargo ready for shipment 1.14 Steps 1.1 to 1.7 should be carried out under the supervision of the master or shipper Steps 1.8 to 1.12 should be carried out under the on-site supervision and responsibility of a representative of the hydrogen peroxide manufacturer or under supervision and responsibility of another person familiar with the safety-relevant properties of hydrogen peroxide The following procedure should be applied when tanks having contained hydrogen peroxide solution are to be used for other products (unless otherwise specified, all steps apply to the tanks and to all associated equipment having been in contact with hydrogen peroxide): Hydrogen peroxide cargo residue should be drained as completely as possible from tanks and equipment .2 Tanks and equipment should be rinsed with clean water, and subsequently thoroughly washed with clean water .3 The interior of the tank should be dried and inspected for any residues Steps 2.1 to 2.3 should be carried out under the supervision of the master or the shipper Step 2.3 should be carried out by a person familiar with the safety-relevant properties of the chemical to be transported and of hydrogen peroxide SPECIAL CAUTIONS: Hydrogen peroxide decomposition may enrich the atmosphere with oxygen and appropriate precautions should be observed Hydrogen gas may be evolved in the passivation processes described in paragraphs 1.8.5, 1.9.2 and 1.9.4, leading to the presence of an explosive atmosphere in the tank Therefore, appropriate measures must be taken to avoid the build-up or the ignition of such an atmosphere Compiled by Nicholas H Moore ... 1994 January 1998 January 1998 January 1998 10 January 1998 Entry into force 30 October 1988 13 October 1990 13 October 1990 July 1994 July 1994 July 1998 July 1998 July 1998 10 July 1998 * * Note:... Dangerous Chemicals Carried in Bulk - a supplement to the IBC and BCH Codes, contained an index of all chemicals referred to in the BCH and IBC Codes which provided the various names known for a particular... chapters 17 and 18 of the IBC Code as well as chapters VI and VII of pre-1993 editions of the BCH Code However, since 1993, the fists of products in chapters VI and VII of the BCH Code have been replaced