Fire hydrant systems are the means by which large quantities of water are distributed to premises (and within larger premises) so that the water can be used for fire-fighting purposes. It is normal for fire hydrant systems to be capable of delivering a virtually unlimited supply of water for use by the fire service.
In larger commercial and industrial premises, there is a requirement under building regulations for the installation of private fire hydrants for use by the fire service in the event of a fire.
If the Fire service uses the fire monitor with the capacity of 50,000 litre it finishes with in few minutes, then they need fire hydrants. That is why it is important.
Wet and Dry Risers
In buildings with large floor areas, and in high buildings, hydrant outlets will be required inside in order to overcome the difficulty which the fire service would otherwise have in conveying fire-fighting water to the seat of a fire. In these cases, the hydrants will take the form of landing valve outlets to which a standard fire service pattern hose can be connected. The landing valves will be mounted on wet or dry fire mains, usually referred to as “risers”.
Wet mains or risers are left charged and water is instantaneously available when needed. Dry risers are required to be charged, usually through an external coupling by the fire brigade when they attend the premises, to fight a fire. Dry and wet risers need to be tested on a regular basis — usually annually — to ensure that they will operate as designed, that hose couplings are operational and that valves and wheel cocks are freely moving. It is the duty of the “responsible person” to ensure that these tests are undertaken.