Fire sprinklers are considered the most effective form of fire suppression due to an impressive record in preventing injury, loss of life and structural damage. Fire sprinkler design is fairly simple, and perhaps that is the reason for the sprinkler’s high reliability rate in extinguishing fires and not activating unnecessarily Fire sprinkler parts have innovated with technology and the materials used to make fire sprinkler parts have become more durable and robust. However the original design concept and principle functionality remains the same.
Fire Sprinkler Design
Although fire sprinkler systems can be customised for specific jobs, the basic fire sprinkler is made up of the following components.
The heat detector is responsible for identifying the fire. It does this through a heat sensitive element which distinguishes a fire from a high room temperature by being set to a particular threshold. Sprinklers are normally fitted with a glass bulb element. The bulb contains a fluid with a small amount of vapour. When the temperature threshold is reached the vapour expands and breaks the glass, allowing the water in the pipe feeding the sprinkler head to be released. A fire engineer will work out the ambient temperature of a room or space and set the threshold at approximately 30c above the ambient temperature – this is usually between 68c and 74C.
When a fire is detected and the glass bulb is broken, a valve is released and the pipe feeding the sprinkler head opens up to allow water to pass through at a high speed.
The sprinkler head is the mouth of the sprinkler and designed to withstand high levels of heat so that it will not melt and become ineffective. The sprinkler head douses the fire with water and suppresses dangerous smoke particles in the air.
Sprinkler Fire Alarm
When a sprinkler system is activated an alarm is triggered to alert occupants of the danger and to prompt an immediate exit from the building. The alarm can be connected to a central emergency services network which immediately notifies the fire service.
If a sprinkler system is serving multiple floors it will require a dry riser installation. A dry riser installation for a sprinkler system refers to a vertical mains pipe which feeds water to higher floors through a network of pipes and valves. This enables maximum water pressure for each sprinkler helping to optimize performance.
Fire Sprinklers: Effective and Efficient
Fire sprinklers provide a highly effective targeted method
of putting out fire. It is very common for a single
sprinkler to be solely responsible for putting out
a fire rather than the entire system becoming engaged.
On average a fire put out by the fire service uses
20 times more water than a sprinkler system, meaning
less water damage to a building. Typically a fire
sprinkler will be activated 1-3 minutes after a fire
has started (depending on the temperature threshold
setting), and therefore provides immediate extinguishment.
The fire service may take as long as 10-15 minutes
to arrive at the scene of a fire.