Aim To introduce students to the various types of fire extinguishers and their differing uses
Learning Outcomes At the end of the session students will be able to: Recognise the extinguisher colour coding scheme Describe the principles of operation of portable fire extinguishers Recognise extinguisher suitability for individual risks Recognise the hazards associated with each extinguisher State when it would be suitable to use a fire blanket.
Types of extinguishers Water Foam Dry powder Carbon dioxide Halon.
Method of pressurisation Gas cartridge Stored pressure.
Considerations when using foam extinguishers Check whether the foam is self-aspirating or non-aspirating Check the foams suitability for the type of fire, i.e. is it polar resistant Do not use on fires involving electricity.
Dry powder extinguishers Powders can be effective on varying classes of fires; Class A Class B Class C Class D Or combinations of the above.
Dry powder extinguisher Gas cartridge. Operating lever Carrying handle CO2 cartridge piercer Gas inlet tube CO2 gas cartridge Powder Discharge tube Nozzle
Considerations when using powder extinguishers(1) Avoid inhaling powders especially if chloride based Beware re-ignition when extinguisher is expended Wind and moisture will affect efficiency outdoors Visibility will be reduced.
Considerations when using powder extinguishers(2) Powders will not penetrate hidden spaces Powders always create a mess Although they are non-conductors they will damage delicate electrical equipment.
Main uses of halon extinguishers Small class B or class C fires Fires involving delicate electrical equipment.
Non-use of halons Do not use on fires involving; Chemicals containing oxygen Reactive metals Metal hydrides.
Carbon dioxide extinguisher. Operating lever Safety pin Carrying handle Control valve CO2 gas Discharge horn Flexible high pressure hose Liquid CO2 Discharge tube
Main uses of carbon dioxide extinguishers On small fires involving flammable liquids On small fires involving electrical equipment.
Considerations when using carbon dioxide Discharge will be noisy Visibility may be impaired The discharge horn and hose become extremely cold - do not hold them with bare hands Owing to the poor cooling effect of carbon dioxide, re-ignition may occur.
Confirmation Assessments will be based on this lesson and the corresponding study note Learning Outcomes Recognise the extinguisher colour coding scheme Describe the principles of operation of portable fire extinguishers Recognise extinguisher suitability for individual risks continued…
Recognise the hazards associated with each extinguisher State when it would be suitable to use a fire blanket.