Fire fighters find it easier to use dry or wet risers when a building is on fire. These are systems of pipework used when there is fire in order to acquire water easily. These are quite suitable for high-rise buildings in which dry risers serve as the vertical mains fitted into lift enclosures or staircases.
How Dry Risers Work
Dry riser systems should have an inlet from the ground level of the building and outlets fitted into cabinets in each floor level. This setup will provide fire and rescue teams to put pressure on the main from their appliances.
Unlike wet risers, the pipes of dry risers are not filled with water until such time when fire fighters arrive. It will be their job to connect the pump outlet in one of the appliances into the inlet of the dry riser. From that instance, water will then be drawn from the closest public fire hydrant in which it will be pressurised by the fire pump in order to provide water in the right direction. This will also provide the fire fighting crew with the required pressure at the particular floor level.
Provides Convenience for Fire Fighters
The purpose of dry risers is mainly to provide water within buildings so that fire fighters should not create their own distribution system in the event of fire. This will also be able to avoid any breach in the fire compartments by running hose lines in between.
The fire mains in buildings are required when the structure is higher than 18m. Either dry or wet risers can be used in buildings not more than 50m high. Nevertheless, if the building extends to more than 50m over the access level of the rescue service vehicle, then it is necessary to use wet risers. This is intended because pumping pressure that requires charging the riser will be higher than the fire service appliance. Therefore, to ensure that there is an immediate supply of water available at high levels, wet risers can easily rise up to the challenge.
Strategic Locations in Buildings
It is required that dry risers be within the fire fighting shafts and situated strategically in protected stairs. At the same time, dry riser outlets or landing valves must be situated in enclosures, lobbies or stairs that are protected.
To ensure that dry risers should function properly and ready for use, then it must be under regular inspection and testing. It will be quite a disaster when problems arise in the event of fire, particularly when the installation has been subject to blockages, pipework or air valve failure, and theft.