Each sprinkler head will
open when it reaches a specific temperature and spray water
on to a fire. The hot gases from a fire are usually enough
to make it operate. Only the sprinklers over the fire open.
The others remain closed. This limits any damage to areas
where there is no fire and reduces the amount of water needed.
The sprinkler heads are spaced, generally on the ceiling,
so that if one or more operate there is always sufficient
flow of water. The flow is calculated so that there is always
enough to control a fire taking into account the size and
construction of the building and the goods stored in it
or its use.
Sprinker heads can be placed in enclosed roof spaces and
into floor ducts to protect areas where a fire can start
without being noticed. In a large warehouse sprinklers may
be placed in the storage racks as well as the roof.
At the point where the water enters the sprinkler system
there is a valve. This can be used to shut off the system
for maintenance. For safety reasons it is kept locked open
and only authorised persons should be able to close it.
If a sprinker opens and water flows through the valve it
lets water into another pipe that causes a bell to ring.
In this way the sprinkler system both controls the fire
and gives an alarm using water, not electricity.
by courtesy of BASA |