What you need to know about automatic fire sprinkler systems

Mina Abdo, Senior Fire Safety Engineer at Warringtonfire

Data collected in the US demonstrates that, 'when sprinklers are present, the chances of dying in a fire are reduced by one-half to three-fourths, and the average property loss per fire is cut by one-half to two-thirds, compared to fires where sprinklers are not present.’1

Active fire suppression systems can have a major impact in fire development and spread, and they can be one of the crucial factors in affecting occupant safety. In the event of a fire, automatic sprinkler systems assist in controlling or suppressing the spread of fire throughout the building by limiting its development at the source using water as a firefighter to put out the flames and absorb heat. 

At Warringtonfire Australia, we conduct rigorous testing on multiple automatic fire sprinkler systems to satisfy the requirements of building regulations, ultimately ensuring your product can provide sufficient time for occupant evacuation and fire services intervention.

What are the benefits of fire sprinkler systems? 

Statistics on US examples of fires that occur in a building with sprinklers show that 88% of fires can be controlled by as little as one or two sprinklers when sprinklers were effective 2 . Data provided by Marryatt concludes that 92% of fires are controlled by one to five sprinklers3.

Once installed, an active fire sprinkler system provides a number of benefits to the overall fire safety standards of a building:

• The water spray ensures a reduction in the rate of burning and quantity of smoke produced, subsequently increasing the available safe evacuation time. 
• A reduced fire intensity and duration, which in turn reduces the severity of fire exposure to structural and fire separating elements.  
• A reduction in the chances of a fire spreading beyond the area of origin or flashover occurring.
• An automatic fire sprinkler system is the most cost-effective fire safety measure to satisfy building regulations.

Types of sprinkler systems

There are four basic types of sprinkler systems that can be used for the majority of applications in buildings each categorised as per the following basic types:

1. Wet pipe system
   Wet pipe sprinkler systems comprise a network of piping filled with water under pressure and automatic sprinklers. Automatic sprinklers are provided with heat responsive elements that are generally a heat bulb or fusible link that activates at a specific temperature. In the event of a fire, the heat applied on the sprinkler will activate the sprinkler (i.e. breaks the heat bulb or fusible link), which allows water to discharge from the sprinkler over an assigned floor area. This is the area of protection.
   A wet pipe sprinkler system is the simplest and most commonly used system in various building types and applications.
2. Dry pipe system
   Dry pipe systems are similar to a wet pipe system, though as the name suggests, no water is held in the piping network. Water is held back by a special dry pipe valve, where the piping network is filled with air or nitrogen so that the dry pipe valve is kept closed. Dry pipe systems are provided with automatic sprinklers with heat responsive elements. When sprinklers activate, the pressure in the dry pipe system drops as air escapes from the activated sprinkler, causing the operation of the dry valve by the water flow. Water is then admitted to the piping network and discharged from the activated sprinklers over the assigned area of protection. A dry pipe system is used in applications where the water in the piping would be subject to freezing.
3. Deluge system
   A deluge system consists of a network of piping connected to open sprinklers rather than automatic sprinklers, meaning that the sprinklers are not provided with heat responsive elements. Water is held behind a special deluge valve that is activated by a separate fire detection system. When the deluge system is activated, water flows through the pipe and discharges simultaneously from all of the sprinklers connected to the deluge valve.
   Deluge systems are used for protection against rapidly spreading, high heat release fires (i.e. tunnels, airport hangars, etc.).
4. Pre-action system
   A pre-action system is composed of a piping network charged with air or inert gas under pressure so that the system is airtight, while water is held back by a special pre-action valve. Automatic fire sprinklers are used in the pre-action sprinkler system, as well as an independent detection system that is also installed in the same area as the sprinklers. Similar to the deluge system, the detection system activates the pre-action valve to admit water to flow into the piping network. Since the pre-action sprinkler system is provided with automatic sprinklers with heat responsive elements, water is only discharged from the sprinklers activated by the heat from the fire.
   Pre-action systems could also be arranged so that the pre-action valve is activated when both the detection system and the automatic sprinklers are activated (via receiving an alarm from the detection system and a monitored low-pressure alarm from sprinkler operation). 
   Pre-action sprinkler systems are generally used in applications where there is a concern for accidental water discharge (i.e. data centres, computer rooms, etc.).

Testing sprinkler systems

Reliability is key for active fire protection systems. Warringtonfire Australia’s fire protection system testing ensures automatic fire sprinklers undergo comprehensive testing procedures to meet industry regulation standards. More importantly, they can also limit property damage and protect life, so should always be considered as part of the fire safety systems in a building’s design.

Completing active fire testing through Warringtonfire Australia’s active fire testing programme is one of the best ways of demonstrating commitment to duty of care and the ongoing maintenance of fire suppression systems. We offer bespoke testing programs, in conjunction with meeting necessary standards, to help move products to market faster while maintaining high quality standards.

Reliability is likely to be even higher where sprinkler systems are correctly designed, commissioned and maintained. Warringtonfire Australia’s automatic fire sprinkler testing ensures systems maintain high operational reliability and meet stringent safety regulations.

To find out more about Warringtonfire Australia’s active fire protection testing, contact info.fire.melbourne@warringtonfire.com / +61 (0) 3 4050 7538

[1] Rohr KD and Hall Jr JR, 2005, US experience with sprinklers and other fire extinguishing equipment, Fire Analysis and Research Division NFPA, Quincy MA, p 59.

[2] Hall Jr JR, 2013, US experience with sprinklers and other fire extinguishing equipment, Fire Analysis and Research Division NFPA, Quincy MA.

[3] Marryatt HW, 1988, Fire: A century of automatic sprinkler protection in Australia and New Zealand 1886-1986, Australian Fire Protection Association, Melbourne VIC.