The fire hydrant system is the backbone of the firefighting systems in a building or premises. The system is a water distribution system consisting of water tank, suction piping, fire pumps and a distributed piping system.
The distributed piping system establishes connectivity throughout the building through fire hydrants, hoses and nozzles. The purpose of the fire hydrant system is to provide a readily available source of water to any point throughout the building. This helps in controlling fire during an emergency.
Under normal circumstances, a fire hydrant system is pressurised with water ready for emergency use. When a hydrant valve is opened, the system experiences a drop in water pressure.
The drop in water pressure is detected by a pressure switch which in turn starts the booster pump(s), drawing water from the water supply to increase the water pressure of the system.
Water from the hydrant is then directed through the lay flat fire hose to a nozzle which is then directed to the seat of a fire.
During a fire the fire brigade may provide additional water and boost the water pressure to satisfy the demands of the fire hydrant system. This is carried out by connecting a fire appliance (truck) between an alternate water supply and the booster connection.