An Automatic Fire Sprinkler System is a network of water-filled pipes which starts at your domestic water service line and ends with strategically spaced fire sprinkler heads located throughout your home.

1. Overview of Automatic Fire
Sprinkler Systems
By Rasel Md
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

2. What is the Automatic Fire Sprinkler Systems?
A sprinkler system is an active fire protection method, providing adequate pressure, integrated
system of piping, connected to a water supply, with listed sprinklers that automatically initiate
water discharge over a fire area. Where required, the sprinkler system also includes a control
valve and a device for activating an alarm when the system operates.
Automatic fire sprinkler systems are networks of underground and overhead piping fed by
automatic water supply.
The basis for a fire sprinkler system is to keep a fire at a relatively small size and under control.
The purpose of a commercial or industrial fire sprinkler system is to provide both life safety
and property protection.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

3. Why use Automatic Fire Sprinkler Systems?
• Automatic fire sprinkler systems offer building owners and homeowners a reliable,
effective, economical, and proven protection system that will keep them from losing
the things they value, including their property and the lives of their families,
employees, and the occupants of the buildings they own.
• Automatic fire sprinkler systems are not just a series of pipes and sprinkler heads
randomly placed throughout buildings; they are engineered systems designed to
control a fire within minutes of the fire starting.
• The basis for commercial and industrial fire sprinkler system design is not
necessarily to extinguish the fire but to keep the fire at a relatively small size and
under control until fire department personnel arrive.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

4. Why use Automatic Fire Sprinkler Systems?
• Though fire sprinkler systems may seem simple, they require an understanding of the
hazard; competent design, layout, and installation; periodic inspection, testing, and
maintenance; and revaluation to ensure that the hazard has not changed to the point where
the original system design and installation are no longer adequate to protect it.
• For well over 125 years, properly designed, installed, inspected, tested, and maintained
automatic fire sprinkler systems have provided property protection and life safety with
unmatched success.
• The different types of automatic fire sprinkler systems may have similar characteristics, but
not all systems are alike and to assume so is a mistake. Changes in occupancy, contents,
storage arrangement, and process can render a sprinkler system inadequate and may require
a different type of system to protect the building or structure.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

5. How Do Fire Sprinklers Work?
• Fire sprinkler systems are triggered by
extreme heat and can quickly extinguish a
fire in the room where it started.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

6. Fire Sprinkler System Components
• Pipe and fittings
• Pipe and fittings join together
to provide a conduit for the water.
• Joining methods.
• Piping and tubing materials.
• Fitting materials
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

7. Fire Sprinkler System Components
• Gauges
Small but important component
• Water gauges
• Air gauges
Should not be subjected to freezing temperatures
Should have a control valve capable of draining
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

8. Fire Sprinkler System Components
• Valves
• Water control valves
• Check valves
• Drain valves
• Isolation valves
• Pressure-reducing and pressure-relief valves
• General-purpose valves
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

9. Fire Sprinkler System Components
• Pipe support and stabilization assemblies
• Piping is held in place by the following:
• Bracing, guides, and restraints
• Hanger assemblies
• Fasteners
• With exceptions, all components must be made of ferrous materials that can handle
heat.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

10. Fire Sprinkler System Components
• Automatic sprinkler heads
• Distribute water over a limited area at designated flow rate
• Most operate at a predetermined temperature.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

11. Fire Sprinkler System Components
• Automatic sprinkler heads (cont’d)
Components
• Frame, heat-sensitive element, orifice, orifice
cap, deflector, trim ring/cover/cup/escutcheon
plate, sprinkler head wrench
Types
• Old-style, standard spray, specialty
Identification, labeling, and markings
• Sprinkler identification number
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

12. Types of Fire Sprinkler Systems:-
• Pre-action:- Pre-action fire sprinkler systems are filled with air and water is allowed to pass through when
the smoke alarm or detector goes off.
• Dry Pipe:- Dry pipe sprinklers are similar to pre-action systems as they use pressurized air in the pipe which
exits before water escapes.
• Wet Pipe:- Wet pipe fire sprinklers constantly have water in them. This allows for a quick reaction to a fire
and is the most common type of sprinkler installed in buildings.
• Deluge:-These types of fire sprinkler systems also need a smoke or heat detector like the pre-action system.
A deluge system has open nozzles that can be used when a hazard is present.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

13. Purpose of each main component
Prepare By Rasel-Senior Project Engineer-Globalwid M&E
Stop Valve Valve Monitor Alarm Valve Automatic Fire Sprinkler
Alarm Test Valve Motorised Alarm Bell Pressure Switch Flow Switch
Jacking Pump
Pressure Gauge

14. Purpose of each main component
• Stop Valve - The Stop Valve is used to isolate the water supply, it may also be called the isolating valve. It is
often painted RED in colour with a large black circular handle, and is locked in the OPEN position, allowing
the free flow of water. The stop valve is used to isolate (stop) the water supply coming in to the fire sprinkler
system. Often the Stop Valve is also fitted with a
• Valve Monitor that is used to monitor the state (open or closed) of the Stop Valve.
The water within an automatic fire sprinkler system can be divided into two parts;
 Water Supply or Mains; and
This is the water being fed into an automatic fire sprinkler system from a water supply such as the town mains
or a static water supply such as a tank, up to the Stop Valve
 Installation
The water after the stop valve forms part of the installation.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

15. Purpose of each main component
• Alarm Valve - The Alarm Valve is used to control the flow of water into the fire sprinkler system. This is
accomplished by providing a one way valve that is normally closed when the water pressure on the fire
sprinkler side of the valve exceeds the water supply pressure. When the pressure equalises or falls below the
water supply pressure, the valve opens to enable water flow.
• Automatic Fire Sprinkler - The Fire Sprinkler is also used to control the flow of water. It is essentially a
valve that when exposed for a sufficient time to a temperature at or above the temperature rating of the heat
sensitive element (glass bulb or fusible link) releases, allowing water to flow from only the affected sprinkler.
The operation and subsequent water flow of an automatic fire sprinkler will lead to a drop in pressure within
the fire sprinkler system after the alarm valve.1
• Alarm Test Valve - The alarm test valve is a small valve, normally secured in the closed position. The alarm
test valve is fitted between the sprinkler system side of the alarm valve and the drain. The purpose of the
alarm valve is when opened to simulate the flow of water from a single automatic fire sprinkler.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

16. Purpose of each main component
• Motorised Alarm Bell or Gong - The motorised alarm bell or gong is a mechanical device, operated by the flow of water
oscillating a hammer that strikes a gong, causing an audible alarm signal.
Ancillary Components
In addition to the main components of the fire sprinkler system, there are a series of ancillary (support) components that
regularly form part of an automatic fire sprinkler system.
• Pressure Switch - The pressure switch is an electro-mechanical device that monitors a fire sprinkler system for a fall in
water pressure after the alarm valve. The purpose of monitoring a fall in pressure is to activate a switch that is monitored
by a fire alarm panel or alarm signalling equipment, as the primary method for signalling an alarm to the fire brigade.
• Flow Switch - The flow switch is an electro-mechanical device that monitors the flow of water through a section of pipe
within an automatic fire sprinkler system. Flow switches are often fitted with a mechanical delay (up to six minutes)
preventing small or minor water flow fluctuations from signalling an alarm. When sustained water flow is detected by a flow
switch, a signal is transmitted to a fire indicator panel. This signal is then used to determine which section (floor) of a fire
sprinkler system has water flow. Note: Most flow switches fitted to automatic fire sprinkler systems are NOT set to
automatically call the fire brigade.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

17. Purpose of each main component
• Jacking Pump - Jacking are manual (hand) or electric (semi-automatic or fully automatic)
pumps are not always fitted to an automatic fire sprinkler system. They however provide a
method of pumping (boosting) water from the water supply to the fire sprinkler system
after the alarm valve. This leads to an increase in water pressure in the fire sprinkler system,
thus forcing the alarm valve into the closed position. Jacking Pumps have a secondary
function of maintaining the water pressure within a fire sprinkler system reducing the
likelihood of false alarms caused by low pressure, caused by small water leaks.
• Pressure Gauge - A pressure gauge us a mechanical device that is usually fitted to an
automatic fire sprinkler system. There are usually two gauges fitted to a system, one showing
the water supply pressure and the second showing the installation pressure. Normally the
pressure differential should be not less than 200 KPa.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

18. Principle of operation
Normally an wet pipe automatic fire sprinkler system, is fully charged with water coming from a known reliable
water supply. The installation is pressurised with the alarm valve secured in the open position. When a 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.
When this occurs water from the water supply will pass through the alarm valve to the affected fire sprinkler and
also past the alarm bell. The resultant pressure drop will also activate the alarm pressure switch, which in turn
will activate an alarm calling the fire brigade.
A flow switch will also 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 (but may not call the fire brigade).
The water supply may be isolated (stopping the flow of water to the affected fire sprinklers) by closing the stop
valve.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

19. Principle of operation
• Circuit
A circuit comprises an unbroken path (usually a pair of wires) along which an electric current exists or is
intended or able to flow. In fire alarm terms this generally means the wiring connecting one or more detectors to
the fire panel.
• Zone
A zone is a group of one or more detectors, grouped by their common location or in the case of a collective
circuit all of the detectors on that circuit. Another way to describe a zone is one of the following;
1. one or more detectors on an single collective circuit or;
2. one or more detectors, in a common location, defined in software on an addressable circuit.
Standards also limit the number of detectors a zone may comprise.
Prepare By Rasel-Senior Project Engineer-Globalwid M&E

20. Thank You
Prepare By Rasel-Senior Project Engineer-Globalwid M&E