Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants
Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants



Navigation

Client login
Forgotten password
Follow us on Twitter Follow us on Facebook Subscribe to our blog

Lawrence Webster Forrest
Legion House
Lower Road
Kenley
Surrey
CR8 5NH

Tel: +44 (0)20 8668 8663 Fax: +44 (0)20 8668 8583
E-mail: fire@lwf.co.uk

Fire Engineering Design and Risk Assessment - Fire Suppression - Foam Systems - Part 1

Posted by LWF: 02/05/2018 14:45

In LWF’s Fire Engineering blogs for Architects and others involved in building design, we have been looking at fire suppression systems, most recently sprinkler systems for both industrial and residential purposes. In part 1 of this series, LWF discusses the design criteria for foam systems. 

Most commonly, foam systems are used to protect areas where flammable liquids and surface fire hazards are a risk factor. The type of foam used varies according to several criteria – the type of system, water supply pressure and if the water source is shared between several hazard areas or not.

Reference documents which are relevant to foam systems include:

BS 5306-3:2017 - Fire extinguishing installations and equipment on premises. Commissioning and maintenance of portable fire extinguishers. Code of practice. 

BS EN 1568-3:2008 - Fire extinguishing media. Foam concentrates. Specification for low expansion foam concentrates for surface application to water-immiscible liquids.

BS EN 13565-2:2009 - Fixed firefighting systems. Foam systems. Design, construction and maintenance

NFPA 11 - Standard for Low, Medium and High-Expansion Foam

NFPA 16 - Standard for the Installation of Foam-Water Sprinkler and Foam-Water Spray Systems

The foam concentrate most appropriate for a particular fire risk is mixed with an appropriate ratio of water which produces a ‘foam solution’. The solution is charged with air to form a bubbly mixture designed to flow onto the surface of a flammable liquid. 

The charged solution is then able to extinguish a fire by smothering the flames. The foam mixture prevents air mixing with the flammable vapour emitted by the flammable liquid.

The coating of foam mixture also suppresses the release of flammable vapours from the fuel surface and provides a barrier between the flames and heat and the fuel surface. It cools the fuel surface and therefore the sources of fire ignition.

Foams must be able to flow freely, form a tough and consistent blanket over the flammable liquid, resist heat and fuel pick-up and retain water within the mixture in order to be effective in a fire. 

While foam solutions are ideally suited to flammable liquid and surface fires, they can also be used for class A (ordinary combustible) fires where appropriate. However, they are not generally suitable for use where there are live electrical hazards or three-dimensional running fuel fires.

In part 2 of this series looking at Foam Systems, LWF will look at the types of foam concentrate which may be used. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact Peter Gyere on 020 8668 8663.

While care has been taken to ensure that information contained in LWF's publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.

Leave a reply

  *

  *

 


CAPTCHA Image

[ Change the image ]


*Required

Subscribe to our fire safety blogs

Bulletins
Email Format
* indicates required

FIRE SAFETY BLOGS

  • Fire Safety for Healthcare Premises - Vertical Escape - Part 23

    In LWF’s blog series for healthcare professionals, we look to give information on best practice in fire safety for hospitals and other healthcare premises. In part 22 of this series, we looked at the issue of vertical escape in relation to stairways and ascertained that in effect, all stairways in a hospital must be considered escape stairways as they would be used for escape in case of fire. In part 23, we will continue looking...

    Read more...

  • Facilities Management & Fire Safety - Inspection, Testing and Maintenance - Part 1

    In LWF’s blog series for Facilities Managers or those with an interest in or responsibility for fire safety, we aim to give an overview of best practice and methods of applying or maintaining fire prevention provision. In part 1, the importance of inspection, testing and maintenance of fire protection measures is discussed.Once fire protection measures are installed in a building, it would be comforting to think that they were simply waiting in case they...

    Read more...

  • Fire Engineering Design and Risk Assessment - Foam Proportioning - Part 4

    In LWF’s fire engineering blog series for Architects and others in the building design business, we have been looking at fire suppression systems and in particular, foam systems. In part 3, it was ascertained that foam proportioning is the means by which foam concentrate is mixed with water at the necessary ratio. An overview of inductors (also known as line proportioners) was given. In...

    Read more...

  • Fire Safety for Healthcare Premises - Vertical Escape - Part 22

    In LWF’s blog series for healthcare professionals, the aim is to give information on best practice of fire safety in hospitals and other healthcare premises. In part 21 of this series, LWF looked at the necessary considerations of hospital streets and escape route widths. In part 22, we will look at vertical escape using stairways.While it is possible for organisations to denote certain staircases as escape stairs (and therefore, certain staircases are not classed...

    Read more...

  • Fire Engineering Design and Risk Assessment - Foam Systems - Part 3

    In LWF’s Fire Engineering blog series for Architects and others in the building design business, we have been looking at fire suppression systems and, in particular, foam concentrate systems. In part 2, we began an overview of the different types of foam concentrate and part 3 will continue from that point before discussing foam proportioning.Synthetic, or high expansion foam is produced from detergents and, as a result, can produce great quantities of ‘bubbles’ making...

    Read more...

Case Studies

The Wohl Neuroscience Institute - Fire Safety, Strategy & Engineering
Key Facts: Client: King’s Clinical Neuroscience Institute Project Manager: MACE Ltd Designers: Devereux Architects/Allies and Morrison Approximate Size: 7,400m2 Description of the Project:...

Read more..

General Bulletins

Fire - The External Risk
When we consider fire safety, our focus is normally from within, what can we do to prevent the occurrence of fire and how we can limit its damage.  Whilst this is the correct stance to take, we m...

Read more..

Technical Bulletins

Evacuation Modelling - Factor in Human Behaviour
Evacuation of buildings can be analyzed in different ways. Approved Document B (ADB) which provides guidance on meeting the requirements of the England and Wales Building Regulations with regard to fi...

Read more..

Site map | Web development London