Halocarbon Fire Suppression Systems

Our company completes the design, installation and maintenance of Halocarbon chemical gas automatic extinguishing systems.

Such systems are particularly suited to critical areas or those containing high-value assets, where rapid fire extinguishing is required. Some examples include control rooms, laboratories, military vehicles and vaults.

These gases have proved to be excellent in converting Halon 1301 or NAF S-III systems (now decommissioned due to being considered harmful to the ozone layer), as the same storage cylinders can be reused after proper reclamation.

TYPES OF GAS 

Halocarbon gas extinguishing systems utilise compressed and liquefied extinguishing gases, such as hydrofluorocarbons and fluoroketones and – just like inert gases – these chemical gases are defined as Clean Agents.

HFC-227ea, Heptafluoropropane, with chemical formula C3HF7

 HFC-125, Pentafluoroethane, with formula CF3CHF3

HFC-23, Trifluoromethane, with formula CHF3

FK-5-1-12, Dodecafluoro-2-methylpentan-3-one, chemical formula CF3CF2C(O)CF(CF3)2, latest-generation gas and unique due to not being a Hydrofluorocarbon.

HOW HALOCARBON GAS WORKS

When used in fire-fighting, chemical gases or halocarbon have a double action, given that they not only chemically attack a fire, battling the free radicals of the chain reaction that feeds the flames, but also physically attack the fire, cooling the environment in which they are discharged during the transition from liquid to gas state. This makes them extremely efficient extinguishers.

ADVANTAGES AND DISADVANTAGES

Advantages

• Rapid extinguishing of the fire thanks to the brief discharge time (less than 10 seconds);
• A very low number of cylinders compared to the Inert alternative, due to lower extinguishing concentrations;
• A low level of toxicity and impaired oxygen level, rendering them suitable for use in areas that are normally occupied;
• Zero electrical conductivity, hence being suitable for protecting control rooms, servers, data processing centres, etc.;
• They do not leave residues after discharge, allowing for an immediate resumption of activities;
• Storage pressure in the cylinder of 25–45 bar, being much lower than the 200–300 bar of inert gases, allowing not only a reduction in risks during the handling and storage of the cylinders but also a limitation of the distance between the cylinder pack and area protected;
• Generally, they do not need overpressure dampers as they produce low pressure peaks.

Disadvantages

• Higher costs compared to inert gases;
• Possible marked environmental problems, especially regarding the Global Warming Potential (GWP) of HFC gases;
• In contact with fire, many chemical gases give rise to traces of harmful decomposition products, such as hydrofluoric acid (HF);
• The environment must be closed and well sealed to ensure the rapid and correct extinguishing of the fire, thus closing devices on doors, windows and ventilation channels must be installed;
• It is necessary to carry out a Volume Integrity Test (Door Fan Test) at the end of the installation and each time work is carried out in the room that could affect permeability.

To avoid any unnecessary discharge of one of the HFC-227, HFC-125, HFC-23 or FK-5-1-12 gases that characterise our fire-fighting systems, activation can be managed by a smoke detection system with double-crossed consent, which we can plan and create. A chemical gas fire-suppression system requires particular testing upon completion of the installation and periodically, in order to verify the air-tightness of the room in which the gas is discharged, being the Door Fan Test.

Like all types of fire-fighting and detection systems, maintenance and assistance for these system types are also included in our exclusive Service packages.