Appendix
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.951(23) – Improved Guidelines for Marine Portable Fire Extinguishers – (Adopted on 5 December 2003) - Annex - Improved Guidelines for Marine Portable Fire Extinguishers - Appendix

Appendix

  TYPES OF EXTINGUISHER
Extinguishing medium used: Water Foam Powder Carbon dioxide Clean agents
Water, with possible salts in solution     Water solution containing foam generating substances Dry chemical powders Pressurized carbon dioxide  
Expellant charge of the extinguisher (stored pressure or cartridge as indicated):   Carbon dioxide or other pressurized inert gases or compressed air (stored pressure or separate cartridge)     Carbon dioxide or other pressurized inert gases or compressed air (stored pressure or separate cartridge) Carbon dioxide or other inert gases or dry air (stored pressure or separate cartridge)    
The discharge of the extinguisher is achieved by:   Opening of the valve. Action of pressurized gas (opening of the cartridge)     Opening of the valve. Action of pressurized gas (opening of the cartridge) Opening of the valve. Action of pressurized gas (opening of the cartridge) Opening of the valve of the container constituting the extinguisher  
The discharged extinguishing medium consists of: Water with possible salts in     Foam containing the gas used Dry chemical powders and carbon dioxide or other gas Carbon dioxide  
The discharged extinguishing medium causes the extinction of the fire by: Cooling of the burning materials. Water evaporation and consequent formation of a local atmosphere (water/steam) which isolates the burning products from the surrounding air Formation of a foam layer which isolates the burning products from the surrounding air and cooling in the case of class A fires Inhibition of the combustion process by the interrupting the chemical reaction. Some separation of burning materials from the surrounding air Formation of a local inert atmosphere (carbon dioxide) which isolates the burning material from the surrounding air. Smothering and cooling action of carbon dioxide  
The electrical resistance of the discharged extinguishing medium is: Very low Very low     Varied Very high. Under intense heat some powders may be electrically conductive Very high  
Operating peculiarities and limitations: The jet or spray of the extinguisher should be directed towards the base of the fire Powder mixture subject to windage; they may therefore have reduced effectiveness in the open or in ventilated spaces Gas subject to windage; they therefore have limited effectiveness in the open or in ventilated spaces
  The extinction of the fire achieved only when all the burning surface is covered by foam
Disadvantages and dangers: Not to be used where there is electrical hazard Generated powder mixtures may be suffocating and can impair vision. Powder can damage electrical contact. Carbon dioxide may be suffocating
     
Maintenance: Extinguishers with copper or copper alloy body should not be polished with products of corrosive or abrasive nature which may cause wall thickness reduction. Such extinguishers should be avoided but where used they should preferably be painted externally.      
The charge can freeze at temperatures of about 0°C (unless the charge is made non-freezable chemically) The charge can freeze at about 5°C.The charge can be altered by elevated temperatures (about 40°C or more). Therefore, the extinguisher should not be installed in positions where it may be exposed to high or low temperatures. Some types of powder may be altered by humidity, therefore, avoid the refilling of the extinguisher in humid locations.    
  Avoid installing the extinguisher in excessively warm locations, where the internal pressure of the carbon dioxide in the cartridge might rise to a very high value   When a carbon dioxide container is provided, avoid the installation of the extinguisher in excessively warm locations, where the internal pressure of the carbon dioxide in the container might rise to very high values.  
Parent topic: Annex - Improved Guidelines for Marine Portable Fire Extinguishers
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