Deluge fire sprinkler systems are generally used in industrial type hazard areas which will require water to be applied over a large hazard area during a fire emergency. In a deluge sprinkler system, water is held back in a separate supply zone, and is not sitting within the piping itself that connects with the sprinklers. Nor is there any pressurized air in the piping, as is often found in different sprinkler systems. The sprinkler orifices are ‘open’ and thus the pipes are not able to hold back any water or pressurized air. The water is held in the supply zone by way of a mechanically latched valve called a deluge valve. This valve is opened when the fire alarm system detects a potential fire, which can be detected in a variety of ways. The fire alarm device may include smoke detectors, heat detectors, or even optical flame detectors. When the system detects a fire, the deluge valve is automatically opened, thereby allowing water to rush from the supply, through the piping, and out of the open sprinkler heads. In other cases, the deluge valve can also be opened manually. The deluge valve is ‘non-resetting’, which means that once it is opened, it will remain so.
A Non-Traditional System
Deluge fire sprinkler systems differ from the more traditional systems in two main ways. Firstly, the sprinkler heads in deluge systems, as mentioned, are always open, and thus when the deluge valve releases the water, it will automatically flow out of every single sprinkler that that is connected to the water supply. This allows for a very fast and reliable flow of water over a large area, since it guarantees that water will be flowing out of every single attached sprinkler head simultaneously. Secondly, some deluge systems incorporate foam concentrate and solution mixed with the water, so that along with water, a foam blanket is also discharged from the sprinkler heads. This extra blanket of foam not only helps extinguish the current fire, but also helps in controlling the fire from spreading to new areas.
Since deluge fire sprinkler systems are excellent at providing large volumes of water throughout all of the premises simultaneously in a reliable fashion, these systems are often chosen for areas which have the following three concerns. Firstly, areas where high velocity water suppression is necessary will often use deluge systems. High hazard areas such as chemical storage facilities or power plants, which will need this high velocity of water to ensure the fire does not spread, will often use these systems. Secondly, areas that require significant amounts of water to control and extinguish a fire will use deluge systems. Areas with hazards containing flammable liquids or with large amounts of combustible materials will require a lot of water to be ejected at once, and thus here too deluge systems are often chosen. Thirdly, areas where rapid fire spread is a main concern also often use deluge systems. Since these systems provide a simultaneous application of water over the entirety of the hazard, these systems are excellent at preventing the spread of an already existing fire.
Got questions? Ask us anything about fire protection system design!