Foam extinguishing method for fire protection onboard chemical tankers
Fire prevention is one of the most essential safety measures on board a chemical tanker. Foam extinguishing is provided on many chemical tankers and on a majority of modern large crude oil carriers. Of
all the extinguishing methods in the IMO Code foam is preferred, but the use of dry powder is generally accepted
as an equivalent method.
Water soluble chemicals, e g. acetone, alcohols, have a tendency to break down conventional foams and render them in effective. Chemical tankers should therefore be provided with alcohol- resistant foam ( "alcohol foam").
Fig: Chemical tanker crew wearing protective clothing
Heavy foam (water/air ratio abt 1:15) is in modern tankers distributed by means of several foam guns which can cover the entire deck area, by means of portable jets or by means of long portable pipes. The latter are intended to be used for the introduction of foam into a tank on fire without risk for the foam to dip underneath the liquid surface. Foam has a limited extinguishing effect on very gassing cargoes: the gases penetrate the foam and burn on top of it.
Foam is a good method for fire prevention: a deck area or a free cargo liquid surface can be protectively foam covered if there is a danger of fire. If a liquid surface is to be foam covered: direct the foam onto a bulkhead or other vertical surface and let it spread from there and float out to cover the entire liquid surface. The foam operator may have to be shielded against heat radiation by means of a water spray.
Medium density foam (water/air ratio abt 1:200) is used in enclosed spaces such as pump rooms. Medium density foam can be produced very simply in fixed distribution jets under deck, in e g a pump room, by using the ejector power of the water stream to draw air into the water foam mixture. Medium density foams are intended to cover the bottom part of a compartment. The installation is very simple and relies on starting the fire-pump only.
Light foam (water/air ratio 1:200 - 1:1000) is only used in enclosed spaces such as engine and pump rooms. It is usually produced by means of a water driven fan which blows up the foam mixture. The foam is intended more or less to completely fill up the compartment in question.
Light foam is sometimes used as a preventive blanketing medium when "hot work" (e g welding) has to be carried out in a cargo tank, which may not have been possible to clean perfectly. The whole tank bottom is then foam covered, leaving only the work location free. Of course the tank has to be guaranteed gas free before starting hot work. Similarly neighbouring tanks can be protected before welding is started on bulkheads.
Summarized below are recommended fire fighting methods for modern chemical tankers:
Total flooding method for seagoing chemical tankers
Water extinguishing method for fire protection
Foam extinguishing method for chemical tankers
Dry powder fire extinguishing method
Related Info:
Controlling the atmosphere in cargo tanks with nitrogen supplied from shore
How to determine the level of a liquid in a chemical tank
Poisoning and required first aid treatment onboard
Controlling the atmosphere in cargo tanks with nitrogen supplied from shore
Static electricity -How they generate & required safety precautions
After tank cleaning gas freeing safety guideline for chemical tankers
Draegar safety tube prior entering enclosed spaces
Preparations prior allowing personnel into cargo tanks / enclosed spaces
How to rescue injured or unconscious person from enclosed spaces
Preparations for hot work and safety precautions
Tank cleaning fatality- case study & lessons learned
Tank cleaning and posoning hazards
Testing of tanks and cargoes
Practical tank cleaning methods for various noxious liquid cargo
Special tank cleaning method
Determining proper tank cleaning by acid wash method
Supervision of all tank cleaning and gas freeing operations
Disposal of tank washings, slops and dirty ballast - safe method
Main Info pages!
Home page ||| Chemical hazards ||| Cargo planning & Stowage ||| Cargo loading ||| Cargo documents ||| Safe stability ||| Cargo care ||| Preparation for unloading ||| Inert gas systems |||Gas freeing ||| Nitrogen handling ||| Chemical handling Safe practice |||Handling equipments ||| Cargo & Ballast pumps ||| Cargo tanks |||Tank cleaning |||Special cargoes |||Spills emergencies |||Fire protection
Chemicaltankerguide.com is merely an informational site about various aspects of chemical tankers and safety tips that may be particular value to those working in: Chemical Handling, Chemical Storage, Liquefied Chemical Suppliers, Chemical Shipping, Chemical Transportation, Chemical Terminals, Bulk Chemical Services and Chemical Processing. If you are interested in finding out more about chemical tanker guideline please visit IMO official website. For any comment please Contact us
Copyright © 2011 Chemical Tanker Guide.com All rights reserved.
Water soluble chemicals, e g. acetone, alcohols, have a tendency to break down conventional foams and render them in effective. Chemical tankers should therefore be provided with alcohol- resistant foam ( "alcohol foam").
Fig: Chemical tanker crew wearing protective clothing
Heavy foam (water/air ratio abt 1:15) is in modern tankers distributed by means of several foam guns which can cover the entire deck area, by means of portable jets or by means of long portable pipes. The latter are intended to be used for the introduction of foam into a tank on fire without risk for the foam to dip underneath the liquid surface. Foam has a limited extinguishing effect on very gassing cargoes: the gases penetrate the foam and burn on top of it.
Foam is a good method for fire prevention: a deck area or a free cargo liquid surface can be protectively foam covered if there is a danger of fire. If a liquid surface is to be foam covered: direct the foam onto a bulkhead or other vertical surface and let it spread from there and float out to cover the entire liquid surface. The foam operator may have to be shielded against heat radiation by means of a water spray.
Medium density foam (water/air ratio abt 1:200) is used in enclosed spaces such as pump rooms. Medium density foam can be produced very simply in fixed distribution jets under deck, in e g a pump room, by using the ejector power of the water stream to draw air into the water foam mixture. Medium density foams are intended to cover the bottom part of a compartment. The installation is very simple and relies on starting the fire-pump only.
Light foam (water/air ratio 1:200 - 1:1000) is only used in enclosed spaces such as engine and pump rooms. It is usually produced by means of a water driven fan which blows up the foam mixture. The foam is intended more or less to completely fill up the compartment in question.
Light foam is sometimes used as a preventive blanketing medium when "hot work" (e g welding) has to be carried out in a cargo tank, which may not have been possible to clean perfectly. The whole tank bottom is then foam covered, leaving only the work location free. Of course the tank has to be guaranteed gas free before starting hot work. Similarly neighbouring tanks can be protected before welding is started on bulkheads.
Summarized below are recommended fire fighting methods for modern chemical tankers:
Total flooding method for seagoing chemical tankers
Water extinguishing method for fire protection
Foam extinguishing method for chemical tankers
Dry powder fire extinguishing method
Related Info:
Controlling the atmosphere in cargo tanks with nitrogen supplied from shore
How to determine the level of a liquid in a chemical tank
Poisoning and required first aid treatment onboard
Controlling the atmosphere in cargo tanks with nitrogen supplied from shore
Static electricity -How they generate & required safety precautions
After tank cleaning gas freeing safety guideline for chemical tankers
Draegar safety tube prior entering enclosed spaces
Preparations prior allowing personnel into cargo tanks / enclosed spaces
How to rescue injured or unconscious person from enclosed spaces
Preparations for hot work and safety precautions
Tank cleaning fatality- case study & lessons learned
Tank cleaning and posoning hazards
Testing of tanks and cargoes
Practical tank cleaning methods for various noxious liquid cargo
Special tank cleaning method
Determining proper tank cleaning by acid wash method
Supervision of all tank cleaning and gas freeing operations
Disposal of tank washings, slops and dirty ballast - safe method
Main Info pages!
Home page ||| Chemical hazards ||| Cargo planning & Stowage ||| Cargo loading ||| Cargo documents ||| Safe stability ||| Cargo care ||| Preparation for unloading ||| Inert gas systems |||Gas freeing ||| Nitrogen handling ||| Chemical handling Safe practice |||Handling equipments ||| Cargo & Ballast pumps ||| Cargo tanks |||Tank cleaning |||Special cargoes |||Spills emergencies |||Fire protection
Chemicaltankerguide.com is merely an informational site about various aspects of chemical tankers and safety tips that may be particular value to those working in: Chemical Handling, Chemical Storage, Liquefied Chemical Suppliers, Chemical Shipping, Chemical Transportation, Chemical Terminals, Bulk Chemical Services and Chemical Processing. If you are interested in finding out more about chemical tanker guideline please visit IMO official website. For any comment please Contact us
Copyright © 2011 Chemical Tanker Guide.com All rights reserved.