Fire sprinkler systems are often part of a complete fire protection plan, where they are built into the fire alarm system. They are designed to either kill off a fire or contain it until more help arrives. Although mostly for large buildings with large fire safety systems, there are also smaller fire sprinkler systems available today, for small households.
It has been proven many times, that fire sprinklers are able to prevent or lessen the risk of death from fire breakouts, by as much as 80%. It is a good idea to install a fire sprinkler system if you can afford one.
In some countries with strict building safety codes, fire sprinklers are required to be installed in all high rise buildings where firefighters often have difficulty getting access to, and bringing water to that height. Obviously, fire sprinklers can put out a fire, even before the fireman arrives.
Types of fire sprinkler systems
There are several types of fire sprinkler systems, but they are usually
- Wet pipe systems
- Dry pipe systems
- Deluge systems
The wet pipe systems are connected to a main water supply, and always have water in the piping, while the dry pipe systems do not. Dry pipe systems have their piping filled with air while the water resides in a separate area, and a safety valve keeps them in place.
When the valve is released due to a fire, the water will then gush into the piping system, and out the sprinkler heads. They are normally installed in places subjected to freezing temperatures, and have a slower response time compared to wet pipe systems.
Deluge systems will have all their heads spraying water at the same time. They are the most effective in putting out fires on the spot. Other types of fire sprinklers include foam water sprinklers, which spray water and anti fire foam concentrate on the fire.
How do fire sprinklers work?
A fire sprinkler system is just a water piping system with sprinkler heads installed at intervals. The sprinkler heads are fitted on the ceiling. Each fire sprinkler head operates independently of the others, and has a heat sensitive bulb filled with liquid that explodes when the bulb is exposed to a certain temperature. Less commonly, some designs have heat sensitive metal instead.
The bulb is connected to a seal which stops the water from coming out. However, if there is a fire nearby, the high temperature will cause the pressure of the liquid in the bulb to rise, and when it gets too much, the bulb will shatter, releasing the water from the piping that is connected to it. This temperature threshold varies from one sprinkler design to another. Some only break at very high temperatures. These will have a different color code.
The water gushes out from valves at the sprinkler head and hits the deflector which breaks it up into droplets which fall over a wide area. In Early Suppression Fast Response (ESFR) sprinklers, the water pressure is more than double that of conventional sprinklers.
The action of one fire sprinkler head is usually sufficient to put out a fire, but if it is not, the heat from the fire will trigger other nearby fire sprinklers to help out. The entire process is automatic, yet highly effective.