Installation Types
Wet-Pipe
The sprinklers in these systems are attached to pipes containing
pressurized water at all times. Individual sprinklers in the vicinity of a fire are set off by heat, allowing water to flow through them immediately.
Wet-pipe systems are used wherever temperatures are high enough to prevent freezing.
Dry-Pipe
In a dry-pipe system, sprinklers are attached to pipes that contain pressurized air. When heat activates the sprinklers to open, the air pressure is reduced, allowing the dry pipe valve
to open and water to flow from the sprinkler.
Dry-pipe systems are usually used only when temperatures are not high enough to prevent freezing (Below 40 deg. F).
Since they have a slower response time, they should be
converted to wet-pipe systems as soon as sufficient heat becomes available.
In situations where only a few sections lack heat, it is recommended to use a combination of dry and wet-pipe systems.
Pre-Action
These systems contain an additional fire-detection device that will recognize a fire before
the sprinklers are activated. The sprinklers are attached to a pipe containing air that may or may not be pressurized.
When the detection device senses a fire, it opens the main valve, allowing water to flow through the
pipes before the sprinklers are set off. When the heat activates the sprinklers, water flows through immediately, as in a wet-pipe system.
Pre-action systems are usually employed in areas that are at risk for serious water
damage due to damaged sprinkles and/or piping.
Deluge Sprinkler System
In these systems, sprinklers are open at all times. They are connected to a dry pipe that is connected to a main water supply.
A fire detection device controls the main valve. When it is activated, the valve opens, allowing
large amounts of water to flow through all of the sprinklers.
The purpose of a deluge system is to quickly wet down an entire hazardous area to prevent a fire from spreading. They are usually used in facilities that contain
high or extra hazard materials such as: flammable liquids, chemicals, and explosives. Rooms with high ceilings sometimes use deluge systems, as it is difficult to direct water over the burning area from such a distance. |
