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 - Sprinkler Installation Design - Part 41

Posted by LWF: 11/04/2018 14:02

In LWF’s Fire Engineering blog series for Architects and others in the building design business, we have been looking at sprinkler installations. In part 40, the additional measures required for life safety sprinkler systems were reviewed. In part 41, we look at those enhancements necessary for property protection. 

Usually, a sprinkler system is designed to deal with a fire in one location, i.e. a fire which develops from at a single source point. It is possible, however, that a fire might have multiple sources. Fires which fall into an ordinary hazard risk group will be subdued or controlled with one to four sprinkler heads, and in cases where a multi-point fire starts on a single floor of a building, the standard sprinkler system is likely to be able to cope. 

If fires were to start on more than one floor of a multi-storey occupancy, an enhanced sprinkler system would be required. 

A standard sprinkler system, complying with British Standards, which is able to deal with ordinary group 2 risks will deliver sufficient water and provide an acceptable flow to between one and 18 active sprinkler heads. Where a fire has multiple start points or there is a failure in the distribution piping network, the system may become overrun and will be unable to maintain adequate water pressure to provide a flow rate to those sprinkler heads which have been activated. The fire would continue uncontrolled.

A failure condition is likely to be where a multi-seat fire ignites on one floor and requires the opening of more than 18 sprinkler heads, or where a partial failure of the sprinklers on one floor (through deliberate damage) can lead to the fire potentially spreading between floors of the building. In addition, a failure can be in the form of a sprinkler riser or main distribution main.

There are safeguards which can be put into place to guard against such failures in a live fire situation.

Where four pumps are provided instead of two, each pump will be capable of supplying the standard demand for a sprinkler system.

To safeguard power to the pumps, each should be connected to both the mains electricity and the secondary power source – such as a standby generator, diesel engines or similar.

The suction manifold positioned to permit two groups of two pumps to draw from it and subdivided by a motorised stop valve which will normally be left open.
A single full-capacity tank should be provided, subdivided into two equal sections with each section having an infill connection. Each infill connection should be sized and connected to provide maximum inflow from either two independent town mains or from a single town main fed from both directions.

In part 42 of this series, we will continue looking at those enhancements which should be undertaken for property protection in case of a multi-seat fire to avoid failures. 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 Engineering Design and Risk Assessment - Halocarbon Agents - Part 12

    In LWF’s fire engineering blog series for architects and others in the building design business, we have been looking at Fire Suppression and most recently, gaseous systems. In part 11, we looked at the effect of gases on the environment and in part 12, we’ll discuss halocarbon agents and inert agents before touching on water mist systems.Halocarbon agentsHalocarbon agents were developed as a viable alternative to halons after the substance was banned for...

    Read more...

  • Fire Safety for Healthcare Premises - Thermoplastic Materials - Part 31

    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 30, we discussed the potential for internal fire spread and in part 31, we take a look at the use of thermoplastic materials in roof lights and lighting diffusers.In part 30, the national and European classifications for linings within spaces contained in healthcare buildings were detailed. The...

    Read more...

  • Facilities Management & Fire Safety - Taking action upon finding a fire - Part 5

    In LWF’s blog series for those who work in Facilities Management, or who have an interest in or responsibility for fire safety, we have been looking at fire procedures; who they are written for and how they should be written.  Parts 3 and 4 of this series looked at summoning the fire service to a fire and in part 5, we look at what other action should be taken upon fire discovery.The issue of...

    Read more...

  • Fire Safety for Healthcare Premises - Internal Fire Spread - Part 30

    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 29 of this series, we looked at plant areas and how they should be designed with safe evacuation in mind. In part 30, we discuss the potential for fire to spread through internal walls and how this...

    Read more...

  • Fire Engineering Design and Risk Assessment - Agents used in Gaseous Systems - Part 11

    In LWF’s Fire Engineering and Risk Assessment blog series for architects and others in the building design business, we have been looking at gaseous systems as a method of fire suppression. In part 10 of this series, the required configuration of gaseous systems was outlined and in part 11, the agents used in such systems will be discussed from the point of view of safety and the environment.After the banning of halon 1301 for...

    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