Merseyside Fire and Rescue Authority endorse the correct installation and use of
Automatic Suppression Systems as a means of securing life, property protection
and Firefighter safety.
Automatic Suppression Systems possess many benefits including supporting the
environment and if more widely used will potentially save millions of pounds for
our economy sustaining business continuity.
The Authority believes there should be wider use of Automatic Suppression
Systems in Domestic, Commercial, Education and Residential premises across
Merseyside and will actively work towards supporting this aim through our wider
work within our Legislative Fire Safety Department.
Are automatic sprinklers a recent invention?
No. The oldest recorded use of automatic sprinklers was in the
Theatre Royal, Drury Lane, in 1812. The updated version is still in use today.
Are they likely to go off by mistake?
No. The likelihood of a sprinkler operating accidentally is 1
in 500,000 (per year of service) about the same as being struck by lightning in
a given year.
Do all the heads operate at once?
No. Each sprinkler head is effectively a self-contained heat
detector and is designed to operate when the predetermined temperature at which
it is set to operate is reached. In normal operation sprinklers are set to
operate at 68°C, and only the head in the vicinity of a fire will operate. If a sprinkler
activates it is unlikely to be a false alarm, unlike smoke detectors that may operate if you
Do sprinklers create more water damage than the fire service?
No. Depending on the type of system and the type of premises it
is designed to protect, each sprinkler head discharges between 50 - 100 litres of
water per minute. Typically the discharge begins about 10 - 30 seconds after the
fire produces enough heat to operate the sprinkler. This is in contrast to the
1,000 - 2,000 litres per minute of water that is likely to be used by the fire
service, due the time taken to respond to the incident. Even if you have
automatic fire detection, the time taken for the fire service to respond will be
greater than that for a sprinkler to operate.
If a sprinkler "false alarms", won’t it create a lot of damage?
Sprinkler systems cannot false alarm as they only operate if the air surrounding
the head reaches the pre-determined temperature. They do not respond to smoke,
steam, dust or sprays from aerosols.
How does a sprinkler work?
A sprinkler head is a temperature-controlled valve that operates, to release a
spray of water, when the heat sensitive element reaches a pre-determined
temperature. The majority of sprinklers installed in the UK are of the ‘glass
bulb type’. This bulb is filled with a coloured liquid and a small bubble of
As the bulb heats to its operating temperature the vapour expands, until the
glass bulb is fractured allowing the water in the pipe behind the head to
escape. The sprinkler head is designed to operate at 30°C above the highest
anticipated ambient temperature. Under normal conditions, in temperate climates,
a rating of 68°C or 74°C will be suitable. However, sprinkler heads with a
operating range from 57°C to 230°C are available as needed.
Is there a risk of vandalism to the system?
Regardless of the type of fire protection system used there is always the chance
of vandalism. However, this is extremely rare and the vandal would get very wet
and be easily identifiable. All sprinkler systems should be fitted with water
flow alarms that provide an alert when a head operates. This alarm can be
connected to an alarm receiving centre that will alert the fire service to the
activation. It is worth noting that deliberate damage to any part of a sprinkler
system would constitute a criminal offence.
Is there a risk of Legionnaire’s disease from sprinklers?
Research carried out by the Fire Protection Association and the Loss Prevention
Council has shown that there is no realistic chance of a member of the public
contracting Legionella pestis from a sprinkler system when it operates. There may
be a small risk to engineering and maintenance staff; this can be entirely
eliminated by proper maintenance of the system. There has been no recorded case
of Legionnaire’s Disease being contracted from any fire protection system
anywhere in the world.
Are sprinklers expensive to maintain?
Unlike other fire protection systems that rely on electronics sprinkler systems
need only very basic maintenance. Usually only two maintenance visits per year
are required, to keep the system in good working order. Weekly and monthly
checks of pumps, pressure gauges and valve settings can be carried by suitably
Further information regarding the use of sprinklers can be found at the British
Automatic Fire Sprinkler Association, www.bafsa.org.uk