The LWF Blog
Fire Engineering Design and Risk Assessment – Firefighting & Hose Reels – Part 15
November 22, 2018 11:23 amIn LWF’s fire engineering blog series for Architects and others in the building design business, we have been discussing firefighting, both from the point of view of the Fire Service and the occupants of a building where a fire starts. In part 14, the distinct types of hose reel were detailed and in part 15, we continue looking at hose reels by examining the operating methods which can be encountered.
Hose reels can be either manually or automatically operated. In the first instance, the isolating valve (which controls water flow) is located on the feed to the reel and is kept closed when the reel is not in use. It must therefore be manually opened prior to the hose being reeled out.
In the case of automatic operation, the turning of the wheel as the hose is reeled out operates a valve in the mechanism allowing water to flow through the hose.
The automatically opening valve is not the same as the isolating valve. In the case of automatically operating hose reels, the isolating valve is kept open and a lock shield valve protects it from mild interference. Some manual reels may be protected by an interlocking device which means that the supply valve must be opened before the hose reel can be turned to release the hose.
It should be noted, however, that on each type of hose reel, the control nozzle on the end of the hose will be in the closed position and must be opened only when the fire location is within reach.
Standards relating to the size of the hose generally require that the diameter of hose should be up to 19mm with a maximum length of 45m, or 25mm with a maximum hose length of 35m.
Due to the design and layout of a building, it may be necessary to place a hose reel on an escape route and as such, they should where possible be located within a recess so that the means of escape is not obstructed in any way. Such recesses are commonly marked by a non-lockable door with clear indications of what is contained within. The doors must open fully back against the wall so as to avoid interfering with reel operation or in providing an obstacle to those people evacuating.
When considering the water supply to firefighting hose reels, it should be capable of providing a minimum flow of 30 litres/minute at the nozzle and being able to sustain two reels in the most hydraulically unfavourable situations. The length of the water jet should be 6 m at the minimum delivery rate. For this to be achieved the supply pipework must be considered and should be a minimum of 25 mm diameter for one hose reel, while 50 mm diameter pipes would normally be the maximum that an average system should require. Thought should be given to protection of the feed pipes in case of frost or sustained sub-zero temperatures.
In part 16 of this series, LWF will look at an alternative approach for the provision of hose reels. 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.