What Is Automatic Fire Sprinkler System (AFSS) ?

Automatic Fire Sprinklers System (AFSS) are specially developed spray nozzles: they are sealed by a glass bulb, and they react automatically to the heat of a fire. Sprinklers go into action when the glass bulb bursts and the nozzle closure is released. Water immediately emerges from the nozzle,and a spray plate effectively distributes it over the entire seat of the fire in the form of a fine shower of water droplets. Depending on the particular risk, the area protected by each sprinkler varies between 9, 12 and 21m2. The choice of spray plate depends on the type and position of the sprinkler installation.

5 Common Types of Fire Protection System

1. Wet Pipe Fire Sprinkler System

A wet pipe fire sprinkler system is by far the most common type of sprinkler system. It consists of a network of piping containing water under pressure. Automatic sprinklers are connected to the piping such that each sprinkler protects an assigned building area. The application of heat to any sprinkler will cause that single sprinkler to operate, permitting water to discharge over its area of protection. 

2. Dry Pipe Fire Sprinkler System

Dry Pipe Fire Sprinkler Systems are used in rooms exposed to the risk of frost. In the dry system, the pipe network is pressurized from compressed air upstream of the alarm valve. If a sprinkler opens in the dry system, the pressure is re-leased. The alarm valve opens and water flows to the open sprinkler.In dry systems, up to 250 sprinklers can be connected to one alarm valve.

3 Pre-Action Fire Sprinkler System

Similar to a dry system, the pipinging a pre-action system does not contain water and may or may not be filled with pressurized air. Water from the supply piping is held back by a pre-action valve and is released to the system piping when the fire detection system and/or sprinklers(depending on the type of pre-action system) are activated.

2 types of Pre-Action Fire Sprinkler System :

1 Single Interlock Pre-Action System :

Single interlock pre-action fire sprinkler systems are used to protect high-value electronic equipment in areas such as computer rooms.

2 Double Interlock System :

Single interlock Pre-action fire sprinkler systems are used to protect high-value electronic equipment in areas such as computer rooms.

4 Deluge Fire Sprinkler System

Uses open sprinklers to deliver a large quantity of water over a specified area in a short period of time.A deluge valve is activated by a fire detection system installed in the same area as the sprinklers. When the deluge valve opens, water flows into the system and discharges from all the attached sprinklers in the system. Deluge systems are used to protect flammable liquid storage, lumberyards, large airplane hangars and electrical transformers.

5 Foam Water Fire Suppression System

The Balanced Pressure Proportioning foam system is the most effective and efficient method of mixing foam concentrate with the water supply. With this method, the foam concentrate is introduced into the sprinkler riser at a similar pressure as the water. The concentrate flows into a ratio controller, also called a proportioner, which is installed in the sprinkler riser. The ratio controller meters the correct quantity of foam concentrate into the water as the water flows through the ratio controller to the sprinkler heads.

Common parts and Automatic fire sprinkler system

  • Pressure switch to start pump
  • Electrical switch cabinet
  • Sprinkler pump
  • Dry alarm valve set
  • Wet pipe network for sprinklers (pendent sprinklers, concealed pipe network)
  • Alarm pressure switch
  • Wet alarm valve set
  • water tank
  • Dry pipe network for sprinklers (upright sprinklers, exposed pipe network)
  • Pressure tank
  • Pump test line with measurement device
  • Fire brigade hose connection
  • Tank filling pump
  • Mechanical alarm bells
  • Compressor
  • Riser
  • Cross Main
  • Branch Lines
  • Fire detection panel

PREVENTIVE MAINTENANCE OF AFSS (PM)

Maintenance matters – any type of sprinkler system will be useless in a fire if the sprinkler control valves are closed and water is prevented from extinguishing the flames. This is the leading cause of extensive fire damage in buildings with a sprinkler system. Sprinkler control valves should be visually inspected periodically to ensure that they are locked or sealed in the wide open position.

LEADING MANUFACTURERS AND BRANDS OF AFSS

BOOKS, WEBSITE AND OTHER REFERENCES:

  • NFPA
  • 3M
  • kidde
  • ISOifDIS 14520: Gaseous Fire Exfinguishing Systems, International Standards Organiza – tion, Homebush, New South Wales, Australia, 2000.
  • NFPA 2001: Standard on Clean Agent Fire Extinguishing Systems, 2000 Edition, NFPA, Quincy, MA, 2000.
  • NFPA 2001: Standard on Clean Agent Fire Extinguishing Systems, 1996 Edition, NFPA, Quincy, MA, 1996.
  • Other Reference