Fire Safety Systems

Question 1

Fire Safety Systems:

The functions of fire alarms and sprinkler systems are

Answer 1

To detect a fire at and early stage.
To sound a building occupant warning or alarm system.
To transmit a signal to summon the fire system.
To interface with other fire safety subsystems.
To commence extinguishment of the fire.

Question 2

Fire Safety Systems:

The three types of dry alarms are

Answer 2

Heat detectors
Smoke detectors
Flame detectors

Question 3

Fire Safety Systems:

Info about heat detectors

Answer 3

Used in applications where smoke detectors are not suitable such as in non-life safety installations where the environment has too many airborne particles due to excessive steam, moisture, dust, humidity or temperature, such as in attics, garages, warehouses, storage facilities, elevator machine rooms or electrical closets.
Heat detectors can operate via fixed temperature or rate of rise.

Question 4

Fire Safety Systems:

Where would you find heat probes

Answer 4

Heat probe detectors are mostly found in kitchen exhaust hood or areas where the ambient temperature is excessively high. Their operating temperature varies and can be calibrated to range from 60-270 degrees.

Question 5

Fire Safety Systems:

4 main groups of smoke detectors

Answer 5

Smoke detection as opposed to heat detection is specifically designed for the protection of life by its ability to detect fire in its early stages.
the 4 main groups are:
Point type
Beam type
Sampling type (e.g. VESDA Very Early Smoke Detection Apparatus)
Residential smoke alarms

Question 6

Fire Safety Systems:

Point type smoke detectors

Answer 6

Detect smoke at a single point or location.
There is two main group of which they work:
Ionisation or Photo-electric

Question 7

Fire Safety Systems:

Beam type smoke detectors

Answer 7

Made up of a transmitter and a receiver located on opposite walls of the building or room being protected. usually found in open areas such as atriums, convention centres and warehouses.
Beam detector relies on the breaking, by smoke, of a long light beam.

Question 8

Fire Safety Systems:

Sampling type smoke detectors

Answer 8

The air sampling system draws air from the protected area through tiny holes in a pipe work system spaced out uniformly around the room. Pipes are connected to detector control unit where there is a fan that creates flow inside. The flow creates a slight vacuum which allows air to be drawn in. A dust filter reduces the chance on contamination. The air is then sampled at a central point by a sensitive light scattering detector.
Can be used in large areas and is very sensitive.

Question 9

Fire Safety Systems:

Residential smoke detector/alarm

Answer 9

Used in residential housing, work on ionisation or photo-electric.
Are stand alone detector and alarm systems.
Powered by either battery or mains power.
New homes are required to have Smoke detectors connected to mains power.

Question 10

Fire Safety Systems:

Main groups of flame detectors

Answer 10

Flame detectors are radiation detectors and belong to two groups:
Infra-red (IR)
Ultra-violet (UV)
Used in the following situations:
Flammable liquid storage
Fuel or lubrication systems
Aircraft hangers

Question 11

Fire Safety Systems:

Sprinkler systems will be required in

Answer 11

Buildings over 25m.
Enclosed carparks accommodating more than 40 vehicles.
Occupancies of excess hazard, e.g. tyre storage facilities, factories.
Shopping centres over 3500m2.
Certain large isolated buildings.
Buildings with atriums installed.

Question 12

Fire Safety Systems:

The basic functions of a sprinkler system are

Answer 12

Detect the presence of fire.
Locate the area involved in fire.
Raise the alarm, both with the occupants of the building and the fire brigade.
Attack the fire.

Question 13

Fire Safety Systems:

Sprinkler system design classification

Answer 13

Sprinkler design and installation has been divided into three main hazard classifications: 
Light hazard (LH) 
Ordinary hazard (OH) 
High hazard (HH)

Question 14

Fire Safety Systems:

Sprinkler system light hazard classification

Answer 14

Light hazard (LH) occupancies are non industrial premises where the amount and combustibility of the contents is low, e.g. Art galleries, churches, offices, etc.

Question 15

Fire Safety Systems:

Sprinkler system ordinary hazard classification

Answer 15

Ordinary hazard (OH) occupancies are commercial and industrial occupancies involving the handling, processing and storage of mainly ordinary combustible materials unlikely to develop intensely burning fires in the initial stages. Further subdivided into 4 groups (OH1-4). 
Examples are footwear manufacturing, motor garages, and paper mills/storage.

Question 16

Fire Safety Systems:

Sprinkler system high hazard classification

Answer 16

High hazard (HH) occupancies are commercial and industrial occupancies with high fuel loads. Has two broad components: 
Process risk - where the materials handled are mainly of an extra hazardous nature likely to develop rapid and intensely burning fires, e.g. aircraft hangers, flammable liquid spraying. 
High piled risk - where goods are stacked above acceptable limits for fire protection by ordinary hazard sprinkler systems, e.g. tyre storage, wooden pallet storage.

Question 17

Fire Safety Systems:

9 Types of sprinkler systems

Answer 17

Wet pipe
Dry pipe
Pre-action
Tail-end
Alternate wet and dry
Drencher
Deluge system
Floor by floor
ESFR (Early Suppression Fast Response)

Question 18

Fire Safety Systems:

Wet pipe sprinkler systems

Answer 18

System pressurised with water. Is activated when sprinkler head in fractured either accidently or from the heat from a fire.
As water is used, pressure in the system drops. When its below or equal to town mains the alarm valve will lift and allow continuous water to flow.
Water will activate a local alarm bell and activate the pressure switch, the latter causing an automatic F&R notification and interface with other fire safety systems.
Water will continue to flow until main wheel valve is shut.
Can be installed where ambient temperature is consistently above 4 and below 70 degrees.

Question 19

Fire Safety Systems:

Dry pipe sprinkler systems

Answer 19

Dry pipe systems don’t contain water. Instead they’re pressurised by air or nitrogen.
Found in areas of extreme cold where there is danger of water freezing or temperatures above 70 degrees.
Operate the same as wet systems, once air flows out and pressure drop alarm allows water to flow through.

Question 20

Fire Safety Systems:

Pre-action sprinkler systems

Answer 20

A dry pipe systems that consists of both heat or smoke detectors and sprinkler heads.
When the detector activated it allows water to fill the pipe system. The when the sprinkler head activates it allows water to flow out.
Gives greater security from accidental release of water.

Question 21

Fire Safety Systems:

Tail-end sprinkler system

Answer 21

Similar to other systems except it only forms an extension to the sprinkler system.

Question 22

Fire Safety Systems:

Floor by floor combined system system

Answer 22

Floor by floor systems consist of sprinkler and hydrant combined systems serving one floor at a time.
In most cases may not have a sprinkler control room but can be isolated in the fire isolated stairwell.
Each floor has its own sprinkler valve set.

Question 23

Fire Safety Systems:

Drencher systems

Answer 23

Can be their own system or an extension of the eternal sprinkler system. Can be operated manually or automatically.
Designed to provide discharge of water over the external openings of the building to prevent the spread of fire to nearby buildings.
Can be wall or curtain drenchers or window drenchers.

Question 24

Fire Safety Systems:

Deluge systems

Answer 24

A system of open sprinklers controlled by a quick-opening valve (deluge valve) which is operated by a system of smoke/heat detectors, sprinklers in the same area as the open sprinklers. Deluge systems can be operated manually.
Deluge systems are dry pipe systems where all the water discharges simultaneously from all sprinkler heads in the zone. Deluge systems are typically used where very rapid fires can develop, e.g. aircraft hangers, flammable liquid stores.

Question 25

Fire Safety Systems:

ESFR (Early Suppression Fast Response)

Answer 25

ESFR systems are quick responding, high volume sprinkler systems that provide exceptional protection for high piled storage occupancies.
They use large volumes of water delivering large water droplets at a high velocity to knock down the fire plume, instead of merely controlling a fire until the original source is depleted.

Question 26

Fire Safety Systems:

Components of a sprinkler system

Answer 26

Question 27

Fire Safety Systems:

2 types of sprinkler heads

Answer 27

Sealed glass bulb

Fusible link

Question 28

Fire Safety Systems:

Sprinkler valve rooms

Answer 28

The room must be secured with a sprinkler valve room key and accessible via a public road. Ideally the room should be fire and or smoke seperated from the building.

Any valves that are locked ina position are opened using a 003 key. 003 and sprinkler valve room keys are located on each urban pumper.

Question 29

Fire Safety Systems:

Fixed fire extinguisher systems

Answer 29

Installed when specific hazards require specialised extinguishing mediums, e,g, oil refineries, computer rooms etc.

Systems could be inergen, NAFS111, FM200, CO2, foam, smoke scrubbing or water mist.

Question 30

Fire Safety Systems:

Alternate solution to be aware of

Answer 30

Alt solutions will have signage in the following places: outside of the building, at the FIP, at the booster cabinet, at all internal hydrants in the fire isolated stairwell or on the open floor plate.

Two lengths or hose required instead of one. (internal hydrants)

Three lengths of hose required instead of two. (external hydrants)

Fire curtains for fire seperation.

Jet fans in car parks.

Heat detectors in apartments for extended travel of distance issues of the occupants.

Question 31

Fire Safety Systems:

In sprinkler valve room FF’s must be able to identify and operate 6 things

Answer 31

Main stop valves

Drain valves and associated pipework (usually black in colour)

Alarm bell isolation valves

Pressure switch isolation valves

Jacking pumps and associated pipework

Sprinkler system block plan

Question 32

Fire Safety Systems:

Fire control room

Answer 32

Large buildings or complexes will usually have a fire control room. these rooms are required to be fire and smoke isolated from the rest of the building and if locked, accessible via a sprinknler valve room key.

This is where firefighters initially attend when responding to an alarm call. On site staff such as wardens and security or building managers will usually attend here as well to liase with ACTF&R.

The fire control room will contain:

Fire indicator panel. (FIP)

EWIS (Emergency warning & intercommunication system) or SSISEP panel.

Fire fan control panel.

Block plans.

Question 33

Fire Safety Systems:

Common faults in alarm systems

Answer 33

Faults in alarm systems can be categorised as:

Transmission signal faults.

Fire panel faults.

Faults in monitoring devices.

Faults in detection devices.

Question 34

Fire Safety Systems:

Sprinkler system activation operating procedure

Answer 34

On arrival go to sprinkler control room.

Shut off local alarm.

Liase with staff or owner to determine the cause of activation or extent of fire.

In sprinkler room determine which valve set is releasing water.

Determine by block plan which area is dischargin water.

Confirm with staff or owner.

A firefighter stay at valve set with radio.

Remainder of crew investigate alarm and begin firefighting if neccessary.

Firefighter at valve set will undo leather strap on main valve and await further instruction.

If fire is present boost system.

When SO determines fire has been extinguished or alarm was false, will give order to shut down valve set.

Firefighter at valve set will close main wheel valve and cease boosting.

Firefighter will then drain valve, isolate pressure switches and close drain once empty.

SO will then request technician to re-instate the system to operation readyness.

FF’s must record actions taken.