Inert gas extinguishing systems

Inert gas extinguishing system (IG-541)

Characteristics of inert gases

• Inert gas (also called Inert) is one of the representatives of the “neutral extinguishing gases” in the Polish market.
• Neutral gases have three characteristic features: 
  • They exist naturally in the atmosphere, so they they do not have negative impact on environment.
  •  It is not electrically conductive.
  •  They do not leave any pollution after discharging.
• Inert gases due to their advantages are used in protecting areas equipped with electronical and other energized devices, and at every place where valuable property is kept.  
• They are recommended to be used in case of areas filled with flammable liquids and gases, moreover they fit perfectly to extinguishing fire and neutralizing the atmosphere, what should prevent fire outburst and explosion.
• They do not affect negatively on environment, they have, so called, Zero Potential of Destroying the Ozone layer (ODP=0).
• They do not influence the greenhouse effect GWP=0.
• Neutral gases’ operation is lowering the oxygen concentration to the value at which the combustion does not exist (i.e. 10-13% volume of air) so it affects physically by lowering the oxygen concentration at the protected area.

Advantages of using the inert gases

• Inert gas causes regular distribution of the extinguishing atmosphere at protected area and it leads to longer lasting of it in the airspace. It allows us to prevent the effect of falling or rising the extinguishing atmosphere and, as a consequence, appearing of zones, in which the fire can rise again.
• Inert system allows reducing the outflow of the extinguishing agent to 42 bar (operating pressure inside the bottle 300bar). Each bottle valve is equipped with separate reductor, which lowers the gas pressure flowing from bottle to collector. What is more, discharging the installation does not cause generating the pressure wave, that can have negative impact on devices kept and on area’s construction. At the Inert system the pressure of gas outflowing from the nozzles is constant  systemie Inert ciśnienie gazu wypływającego z dysz jest stałefor the entire process of discharging the bottle (95% of gas volume should be released at the time not longer than 60sec.) which increases the extinguishing effect and prevents appearing of unexpected losses.
• During extinguishing electric and electronic systems, the agent does not cause thermal shock that can appear by using other extinguishing agents (e.g. carbon dioxide).

Description of the system

• System consists of:
  • tanks with extinguishing agent;
  • bottle valves;
  • pneumatic activator steered by central panel’s signal;
  • pipelines;
  • extinguishing nozzles;
  • detecting-extinguishing switchboard.
• At the Inert gas system, no additional reduction valve at pipelines are used (except from reduction on fabric valves).
• Outlet nozzles are chosen individually by the computer calculating programme for each protected area, including special requirements, e.g. specified time of outflow ≤60 sec. and devices that should be protected.

Usage of neutral gases extinguishing systems

• System may be used to fire extinguishing at following objects and areas:
  • computer rooms;
  • switching stations;
  • archives;
  • monuments;
  • valuable works of art;
  • control room of technological processess;
  • unique medical equipment;
  • telecommunication apparatus;
  • gas turbines;
  • engine test bench;
  • inflammable substances’ storage hall (petrol, oil, paint, lacquers) and many others.

Basic components of fixed extinguishing system

• Fixed extinguishing system for Inert gas is built from following components:
  • tanks: bottles 80l or 140l;
  • extinguishing agent;
  • nozzles 180° or 360°;
  • manometer with pressure switches of tanks and extinguishing agent;
  • main bottle valve (reduction);
  • set of electromagnetic and manual trigger;
  • pressure switch of extinguishing agent’s triggering;
  • pipelines;
  • hydraulic fittings.

• Tanks
  • Extinguishing agent is kept in the tanks equipped with quickly released valve, reducing the pressure of extinguishing agent’s outflow to 60 bar and contact manometres.
  • Tanks and pipelines together create hydraulic system.
  • Tanks are attached to the wall by steel braces chosen on the basis of number of tanks

Bottles

•  Extinguishing agent
  • Extinguishing system is used on the basis of Inert extinguishing agent, which is one of the most popular neutral extinguishing gases used in Poland and all over the world.
  • Gas is commonly used all over the world, not only in industry, but also in the other aspects of everyday life.
  • During the process of extinguishing fire, extinguishing gases fill the protected area making the design concentration, what allows to lower the oxygen concentration at the protected area to about 9-12% (concentration drop about 9-13%).
  • As the consequence of lowering the oxygen concentration, the “combustion triangle” (energy, flammable material, oxygen), and the fire is extinguished.
  • Fire extinguishing effect is reached due to regular distribution of the agent at the area for 60 seconds.
  • Neutral agents do not have negative impact on natural environment and human organism.
    
  • Extinguishing concentrations used do not allow people to stay during extinguishing, evacuation is neccessary.
• Nozzles
  • Nozzles are the last element of gas flow.
  • They are designed in pendant and upright position.
  • They cannot be painted.
  • One should remember about acceptable distance from walls, ceilings and obstacles in the protected area (max 30 cm from walls and ceilings).

 Examplary nozzle.

• Manometer with pressure switch of tanks and foaming agents
  • This manometer is having additional switch and is installed directly on the bottle valve with extinguishing gas.
  • Apart from visible signal it sends electric signal to the control panel.
  • When the pressure lowers below acceptable value, contacts dispel and alarm the pressure drop.
  • Signals from manometers are connected to extinguishing panel at the system.

Tank’s manometer

• The main bottle tank (reduction)
  
  • Each tank with extinguishing agent is equipped with bottle valve that allows to reduce the pressure at the bottle’s outlet to the value of 42 bar.
  • There is a manometer described above in the valve that shows temporary pressure in the tank and alarms about deficiencies.
  • Valve is equipped with several technical connectors to which the main system’s elements are installed.

 Exemplary set of bottles.

• Universal Valve Operator trigger
  
  • UVO trigger (Universal Valve Operator) is part of the system responsible for activating the extinguishing agent from the bottle.
  • It is equipped with electrovalve that, after recieving the signal from panel, causes gas activating from the steering cartridge.