AUTOMATIC FIRE SPRINKLER SYSTEMS

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WELCOME! CFAA Alberta

Types of Water-Based Sprinkler Systems • Wet pipe system – most common • Dry pipe system – areas subject to freezing • Deluge system – open head; detection required • Preaction system – where accidental activation is undesired

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SPRINKLER HEADS!!!

• Many different types of sprinkler heads. • What is your application?

FIRE PROTECTION SYSTEMS

• NFPA 13 recognizes four main types of Fire Protection Systems: • Wet Pipe Systems • Dry Pipe Systems • Deluge Systems • Preaction Systems

• Several variation to each one of these systems may be found, but these four systems are the foundation.

Principle of operation • Wet pipe automatic fire sprinkler system:

• Fully charged with water coming from a known reliable water supply. • The installation is pressurised with the alarm valve secured in the open

position. • Fire sprinkler is exposed for a sufficient time to a temperature at or above the

temperature rating of the heat sensitive element (glass bulb or fusible link) it releases, allowing water to flow from only the affected sprinkler.

• Additional fire sprinklers may also operate if they too are exposed to sufficient heat.

• A flow switch will operate in the affected section of the fire sprinkler system, indicating the location of the water flow. (In the case of a multi-storey building there is typically one flow switch per floor). The flow switch will indicate its location a fire indicator panel.

• The water supply may be isolated (stopping the flow of water to the affected fire sprinklers) by closing the stop valve.

DRY PIPE SYSTEM Principle of operation

• Piping network downstream of the DPV is filled with air.

• Clapper on DPV remains closed – holds back water supply.

• Sprinkler head is opened by heat activation.

• Air is released from piping network. • Pressure switch indicates alarm to

FA panel. • Pressure on clapper is relieved. • Clapper opens releasing water into

the system piping. • Water flows to the now open

sprinkler head.

DELUGE SYSTEM Where and Why?

• Generally used for high hazard industrial applications.

• High velocity suppression to prevent spread of fire.

• Simultaneous application of water over the hazard in order ensure fast suppression.

Operation • Dry piping with open sprinkler

heads • Valve clapper is held closed

through various means (solenoid, wet pilot, dry pilot, manual, etc.)

• Clapper opens releasing water into the system piping.

• Once activated water flows through all open heads on the system.

PREACTION SYSTEM

Where and Why? • Electrical rooms, data centres,

vaults, server rooms, etc. • Generally used to prevent water

damage due to accidental discharge.

Operation • Dry system piping, closed sprinkler

heads and a form of detection. • Valve clapper is held closed until

system actuation (single interlock, double interlock).

• Detection signals panel to activate solenoid.

• Clapper opens releasing water into the system piping.

• Once activated water flows through piping.

• No water is discharged until sprinkler head opens.

Codes and Standards • NFPA 13 – Standard for the Installation of Sprinkler Systems • Alberta Building Code