FIRE PROTECTION FUNDAMENTALS Chapter 7: WATER-BASED FIRE PROTECTION SYSTEMS & EQUIPMENT

FIRE PROTECTION FIRE PROTECTION FUNDAMENTALSFUNDAMENTALS

Chapter 7:Chapter 7:WATER-BASED FIRE WATER-BASED FIRE

PROTECTION SYSTEMSPROTECTION SYSTEMS& EQUIPMENT& EQUIPMENT

An automatic fire extinguishing system, when An automatic fire extinguishing system, when properly designed, installed, and maintained, is a properly designed, installed, and maintained, is a vital component of property and life protectionvital component of property and life protection

Understand the reasons for and the methods of Understand the reasons for and the methods of electrical interconnections between extinguishing electrical interconnections between extinguishing systems and fire alarm systemssystems and fire alarm systems

The technician must realize that this training The technician must realize that this training module does not provide the skills and knowledge module does not provide the skills and knowledge to design, install, inspect, or test such to design, install, inspect, or test such extinguishing systemsextinguishing systems

CHAPTER 7: WATER-BASED FIRE CHAPTER 7: WATER-BASED FIRE PROTECTION SYSTEMS & EQUIPMENTPROTECTION SYSTEMS & EQUIPMENT

CHAPTER 1CHAPTER 1Fire Protection History Lessons LearnedFire Protection History Lessons Learned

1. Chapter Overview and Key Concepts

Primary Purpose of Fire Alarm Systems Reference Infamous Canadian Fires CFAA Program and Expectations The Building Code Building Requirements for Fire Alarm Systems Governing Documents Codes & Standards Plans & Specifications

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How water-based sprinkler system are applied based on the principles of the Fire Tetrahedron

Describe the methods water-based sprinkler system utilize to protect the occupants

Why do Canadian building codes and fire codes contain the parameters under which sprinkler systems must be installed into certain types of buildings.





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Make a distinction between wet pipe systems and dry pipe systems

Identify a Pre-action system and describe how they typically operate

Identify a Deluge system and describe how they typically operate

Analyze how fire alarm systems interoperate with sprinkler systems

Describe Special extinguishing systems




Primary Purpose of Fire Alarm Systems

Reference Infamous Canadian Fires

CFAA Program and Expectations

The Building Code Building Requirements for

Fire Alarm Systems Governing Documents Codes & Standards Plans & Specifications

CFAA 2009

5

Language DefinedLanguage Defined

Term Definition

Deluge System Similar to a pre- action system except the sprinklers are open type. They are not kept closed by a fusible link. The water supply is kept from the system by a “deluge valve” which is released by the activation of supplemental fire detection such as fire detectors (heat or smoke). Once water flows through the system, it is discharged by every sprinkler head in the system.

Dry Pipe System Similar to a wet system, but does not contain water above the clapper. The system side is filled with compressed air, which holds back the water supply by keeping the clapper or “dry pipe valve” closed.

Pre-action System

Similar to a dry- pipe system in that water is kept from entering the piping by a “pre- action” valve. Closed sprinklers are used on piping that is filled with air that may or may not be pressurized. A supplemental electronic fire detection system (separate from the main building fire alarm system) is also installed, serving the same areas protected by the pre- action system.

Sprinkler Head A mechanical device that, when activated, effectively distributes water in a specific pattern over a fire, so as to extinguish the fire or at least contain and control it.

Wet Pipe Sprinkler System

The most common type of sprinkler system is the wet pipe, which contains water under pressure in the sprinkler system pipes at all times. The system uses closed sprinkler heads

Water as an extinguishing agentWater as an extinguishing agent

Physical propertiesHeavy, stable liquidMelting of water absorbs 143.4 BTUSpecific heat of waterConverting 1 lb. of water to steam- 970.3 BTU/lb. (2254.8

kJ/kg)When converted from liquid to vapour, volume increases

1600 times

Extinguishing Properties of WaterExtinguishing Properties of Water

Extinguishment by cooling:Rate of heat transfer is proportional to exposed

burning surface and the surface area of the waterRate of heat transfer – temperature difference

between water and surrounding air or burning material

Rate of heat transfer – vapour content of the airHeat-absorbing capacity – distance the water

travels and its velocity in the combustion zone

Other Extinguishing MethodsOther Extinguishing Methods

Extinguishment by smotheringFoaming agentSteam production

Extinguishment by emulsificationAgitation of two liquids together that normally do not

mix Extinguishment by dilution

Water-soluble flammable materialsEthyl alcohol for example

Electrical Conductivity of WaterElectrical Conductivity of Water

Voltage and current flowingBreak-up of the stream, pressure used, wind

conditionsPurity of the water – resistivity Length and cross-section of the water streamResistance to groundResistance to ground through hose

Use of Water on Special HazardsUse of Water on Special Hazards

ChemicalsCombustible metalsRadioactive metalsGasesCombustible and Flammable liquids

Automatic Sprinkler SystemsAutomatic Sprinkler Systems

Development1st were perforated pipeEdward Parmalee developed first working sprinkler head

Value of Automatic sprinkler ProtectionApply water to fire and give warningDecrease smoke levels and cool areaAllow longer travel distances to exits, higher combustibility of

finishes, etc.

Sprinkler performance95 % satisfactory performanceLargest reason for unsatisfactory performance was

human errorWill control fires

Minimize business interruption and water damageEconomics of sprinkler protection

Automatic Sprinkler SystemsAutomatic Sprinkler Systems

Incipient Stage Smoldering Stage Heat StageFlame Stage

Time (minutes/hours)

Damage

A sprinkler head operates just before the point where collateral damage from water would likely do less damage than the fire. It would be of little value to cause release at an earlier point of fire growth.

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Water Based SprinklersThe most common automatic extinguishing system is

the water-based sprinkler systemFire Tetrahedron reminds us that a fire will not live if

oxygen and high temperatures are excluded from the fire condition

7.3 Water Based Sprinkler Systems 7.3 Water Based Sprinkler Systems

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Water Based SprinklersWhen properly applied, water can cause both of

these conditions and suppress or even extinguish most fires

A sprinkler head (sprinkler) is a mechanical device that, when activated, effectively distributes water in a specific pattern over a fire, so as to extinguish the fire or at least contain and control it.


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Water Based SprinklersA sprinkler head (sprinkler) is a mechanical device

that, when activated, effectively distributes water in a specific pattern over a fire, so as to extinguish the fire or at least contain and control it.


24” Clearance

7.3.1 Wet Pipe System7.3.1 Wet Pipe System

Water flow Switch

Butterfly Supervisory Valve

Flow Switch

Supervisory Valve Monitor

24” Clearance

Tamper Switch

Water flow Switch

Drain valve Closed

Inspectors Test valve Closed

To Drain

Main Riser

To Sprinklers

Control Valve Open

Open Inspectors valve to test Flow Switch

Flow Switch will trip after retard expires

10 GPM required

24” clearance

Monitor Butterfly shut off valve

Flow Switch

Main Riser From Water Supply

2” main drain

The Flow Switch will operate after a continuous flow of 10 GPM or more for the length of the retard time.

System Pressure

Supply Pressure

No Pressure

Pressure Switch

To Water motor gong

Retard Chamber

BVS

“Clapper”, normally closed

Alarm Valve

System Pressure

Supply Pressure

Normal Condition

Test Valve, normally closed

System Pressure

Supply Pressure

No Pressure

Clapper opens

Retard chamber begins to fill

Shut off valve in line with PS10A must be supervised. Use BVS.

LPS

The pressure switch operates when the pressure reaches 6psi.

System Pressure

Supply Pressure

No Pressure

To water motor gong

Alarm Pressure Switch

System Pressure

Supply Pressure

No Pressure

To water motor gong

Clapper opens

WFSR-F trips after retard time expires

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Dry PipeThe dry-pipe piping system is similar to a wet

system, but does not contain water above the clapper

When a sprinkler opens, the air pressure is released thus causing a low air pressure condition in the system

A dry-pipe type of system is typically used in locations where water that is kept in the system may freeze

7.3.2 Dry Pipe Sprinkler Systems 7.3.2 Dry Pipe Sprinkler Systems


Dry-pipe system for unheated properties - the system riser, cross

mains, and branch lines are maintained at the same air pressure.

When the air pressure is bled off the system, the dry pipe valve opens and

water flows into the system.


In a large dry pipe system, several minutes lost while the air is being expelled through the open sprinklers before the dry valve operates. Delay provides time for fire growth. Possible to speed the operation of the system by using a quick opening device.

There are two types of quick opening devices: Accelerators - unbalance the differential in the

dry pipe valve, which causes it to trip more quickly.

Exhausters - function by quickly expelling air fromthe system.


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Pre Action Dry PipeA pre-action system is similar to a dry-pipe system in

that water is kept from entering the piping by a “pre-action” valve.

Closed sprinklers are used on piping that is filled with air that may or may not be pressurized

The pre-action valve is held in place electronically by a solenoid control valve. The solenoid is energized upon the activation of the supplemental fire detection system

A double interlock pre-action system requires two conditions to be met before water is released.

7.3.3 Pre-Action Sprinkler Systems 7.3.3 Pre-Action Sprinkler Systems

A pre-action system:

Used when especially important that water damage be prevented, even if the sprinkler pipes should break accidentally.

Used to protect computer rooms & document

storage areas.

Employs a deluge type valve, fire detection devices, and closed sprinklers.

Will not discharge water into the sprinkler piping

until an indication is received from fire detection devices (other than sprinklers) that a fire may exist.


When water in system, discharged through any sprinkler that is fused.

Usually, air under a low pressure is maintained in piping as a supervisory function.

With leak or break in piping, the supervisory air pressure drops and transmits a supervisory signal without admitting water to the system.



Preaction system

Comparison of operating features for the types of preaction systems

Double interlock preaction system


Where should they be used?

•Where risk of mechanical damage is high

•Where wide fluctuations in temperature could occur

Why?

To reduce the risk of water damage


Type of System A Failure of the Results inSeparate Sprinkler

&Detection System

Detection System No alarm transmitted. Sprinkler system continues to operate.

Sprinkler system No automatic fire extinguishing capability - fire alarm system not impaired.

Pre-Action System Detection systemTotal failure - no alarm capability - no fire extinguishing capability.

Pre-Action System Sprinkler system No automatic fire extinguishing capability - fire alarm system not impaired.

Separate Sprinkler&

Detection System

Consider the following..........


Question: Should pre-action sprinkler systems be used in telephone, exchanges, computer rooms, art storage vaults, etc. ?

Answer: Probably not. These types of hazard areas have precise temperature control and low risk of mechanical damage. The added complexity of a pre-action sprinkler system may actually decrease reliability.


A smoke-detection-type automatic detection equipment should be installed and maintained in accordance with relevant standards. Automatic detection devices should be installed in the following locations:

•At the ceiling level throughout the area;•Below the raised floor (if provided); and•Above the suspended ceiling (if provided)

Where interlock and shutdown devices are provided, the electrical power to the interlocks and shutdown devices should be supervised by the fire alarm control panel.

7.3.3 Pre-Action & Automatic Detection 7.3.3 Pre-Action & Automatic Detection

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DelugeA deluge system is similar to a pre-action system

except the sprinklers are open type

They are not kept closed by a fusible link.

The water supply is kept from the system by a “deluge valve” which is released by the activation of supplemental fire detection such as fire detectors (heat or smoke).

The deluge system allows water to be applied to a fire more quickly than systems which depend on the opening of individual sprinklers as the fire spreads to each head

7.3.4 Deluge Systems 7.3.4 Deluge Systems

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Where to Utilize DelugeWhere fire may flash ahead of the operation of

ordinary automatic sprinklers such as flammable liquid handling or storage

To create a water curtain that will prevent the movement of fire such as openings around escalators in shopping malls


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Where to Utilize Deluge In areas where ceilings are exceptionally high and

there is likelihood that ordinary sprinklers directly over the fire would not open promptly or might open without having an effect on the fire (e.g. aircraft hangers)

To automatically control the water supply to protect against exposure to fires (e.g. window sprinklers)


The purpose of a deluge system is to quickly supply a large volume of water to a protected area

Heat, smoke or flame detectors are installed in same area as the sprinklers. Detection devices control operation of deluge valve

through a tripping device. Unlike wet or dry pipe systems,

sprinklers do not function as detection in a deluge system.

Deluge systems used to protect hazards i.e. transformers.

7.3.4 Deluge Systems7.3.4 Deluge Systems

7.3.4 Deluge Systems7.3.4 Deluge Systems

7.3.4 Deluge System 7.3.4 Deluge System

Internal view – set position

Typical deluge valve

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Monitoring on Fire Alarm If a building has a fire alarm system then sprinkler

systems must be monitored by the fire alarm systemAutomatic sprinkler systems incorporate electrical

devices which Will initiate an alarm signal in case of sprinkler

operation Identify supervisory status (i.e. closed water supply

valves) Indicate circuit trouble conditions

Each sprinkler floor area is required to have its own alarm zone indication at the annunciator panels

Sprinklers trigger at temperatures similar to that of heat detectors

7.47.4 Sprinkler System MonitoringSprinkler System Monitoring

System Pressure

Supply Pressure

No Pressure

Pressure Switch

Retard Chamber

BVS

“Clapper”, normally closed

Alarm Valve

System Pressure

Supply Pressure

Test Valve, normally closed


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7.4.17.4.1 Alarm InputsAlarm Inputs

Sprinkler alarm components include those Sprinkler alarm components include those that operate because of actual flow of water that operate because of actual flow of water

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7.4.17.4.1 Alarm InputsAlarm Inputs



Primary Purpose of Fire Alarm Systems

Reference Infamous Canadian Fires

CFAA Program and Expectations

The Building Code Building Requirements for

Fire Alarm Systems Governing Documents Codes & Standards Plans & Specifications

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7.4.27.4.2 Supervisory InputsSupervisory Inputs

Devices used to signal abnormal conditions that couldDevices used to signal abnormal conditions that could render the sprinkler system ineffective or inoperablerender the sprinkler system ineffective or inoperable

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7.4.27.4.2 Supervisory InputsSupervisory Inputs

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Supervisory The movement (closing) of any type of water supply

control valve Low water level in a storage tankLoss of power to fire pumpFire pump trouble conditionsLow temperature in water supply tank, reservoir or

valve roomHigh or low water level in pressure tanksHigh or low air pressure in pressure tanksHigh or low air pressure in dry pipe sprinkler systemAutomatic operation of fire pumps


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TroubleA fire alarm system is designed to monitor its

electrical circuits for physical abnormal conditions

A fault in the circuit wiring will cause a trouble signal (visual and audible) at the fire alarm control unit

This indication serves to warn building maintenance personnel that abnormal conditions exists

Abnormal conditions may cause the inability for the fire alarm system to detect and indicate alarm and supervisory conditions.

7.4.37.4.3 Trouble Condition InputsTrouble Condition Inputs

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Numerous applications where there is a need to not just detect a fire condition but also to contain, control and suppress the fire

In some circumstance, water is not the optimum choice for doing so as it may cause negative effects

Extinguishing agents are used and often are controlled by supplemental electronic control panels

These sub-systems to a buildings’ main fire alarm system will initiate various signals to indicate alarm, supervisory and trouble conditions.

7.5 Special Extinguishing Systems & 7.5 Special Extinguishing Systems & AgentsAgents

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Gaseous agent extinguishing systems are not a substitute for any of the previously discussed fire protection measures

Gaseous agent extinguishing systems are not an equivalent to a water sprinkler system

If implementation of all of the preceding measures does not attain an acceptable degree of risk reduction then a gaseous fire protection system will be considered.

7.5 Special Extinguishing Systems and 7.5 Special Extinguishing Systems and AgentsAgents

The Four Stages of Fire(Class A Materials)



Damage

A properly designed gaseous agent system causes no collateral agent damage. The choice of detection methodology usually tries to detect and cause release at the earliest stage of the fire, consistent with minimizing the possibility of false discharge.

7.5 Special Extinguishing Systems and Agents7.5 Special Extinguishing Systems and Agents



Damage

Detection and release shall occur well before sprinkler operation would be expected.


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NFPA 2001 - 2004 edition

4.3 Detection, Actuation, Alarm, and Control Systems 4.3.1 General 4.3.1.1 Detection, actuation, alarm, and control systems

shall be installed, tested, and maintained in accordance with appropriate NFPA protective signaling systems standards.

CAN/ULC S524-06, Standard for the Installation of Fire Alarm Systems




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Various fire extinguishing methods and agents can be grouped according to the following four methods of fire controlDilutingSmothering CoolingChain-reaction inhibiting

Each extinguishing method or agent operates Each extinguishing method or agent operates predominantly by means of one of the four methods predominantly by means of one of the four methods listedlisted

Often the primary intent (e.g. smothering) will at the Often the primary intent (e.g. smothering) will at the same time provide a certain degree of extinguishing same time provide a certain degree of extinguishing capability through one or more of the other effectscapability through one or more of the other effects





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A sprinkler head (sprinkler) is a mechanical device that, when activated, effectively distributes water in a specific pattern over a fire, so as to extinguish the fire or at least contain and control it

A sprinkler is a heat detecting device. Typically, only the sprinkler that is affected by the heat from a fire will be activated

SummarySummary




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The most common automatic extinguishing system is the water-based sprinkler system

Canadian building codes and fire codes contain the parameters under which sprinkler systems must be installed into buildings

SummarySummary




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There are different types sprinkler of systems, which utilize water as the suppressing agent. Each system uniquely delivers water to the sprinkler.

The four common systems are: Wet pipe Dry pipe Pre-action Deluge

It is important to understand that if a building has a fire alarm system then sprinkler systems must be monitored by the fire alarm system

SummarySummary




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Each sprinkler floor area is required to have its own alarm zone indication at the fire alarm control and annunciator panels

There are numerous applications where there is a need to not just detect a fire condition by a fire alarm system, but also to contain, control or even suppress the fire

In some circumstance, water is not the optimum choice

This is where special extinguishing systems are typically provided

SummarySummary




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Automatic fire extinguishing system may be installed over a deep-fat fryer in a commercial kitchen

The melting of a heat sensitive fusible link will cause the stored extinguishing agent to be automatically discharged from pressurized cylinders

SummarySummary




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Various fire extinguishing methods and agents can be grouped according to the following four methods of fire control are Diluting Smothering Cooling Chain-reaction inhibiting methods.

SummarySummary