Inert Gas Systems

Our company carries out the design, installation and maintenance of IG 55, IG 100, IG 01 and IG 541 automatic inert gas extinguishing systems.

These types of systems are particularly suited to protecting sensitive areas such as electrical or electronic control units, telecommunications or control rooms for air and rail signalling, control rooms, Data Processing Centres, marine equipment, pharmaceutical industries and laboratories, banks and money deposits, universities, libraries and archives of all kinds, along with museums, art galleries and theatres.

TYPES

Inert gases for use in fire-fighting are typically utilised in the form of normed gas mixtures of Argon (Ar), Nitrogen (N2) and Carbon Dioxide (CO₂), in particular:

• IG‑01: 100% Ar;

• IG‑100: 100% N₂;

• IG‑55: 50% N ₂ , 50% Ar;

• IG‑ 541: 50% N₂, 42% Ar, 8% CO₂.

COMPONENTS OF AN INERT GAS EXTINGUISHING SYSTEM

Automatic inert gas extinguishing systems essentially consist of:

• A 200–300 bar high-pressure cylinder battery with an 80–140 litre capacity, firmly secured to the wall or floor;
• A manifold to which the cylinders are connected via hoses;
• A pressure reducer, being a calibrated orifice capable of lowering the pressure downstream of the manifold to values with a peak of around 50–60 bar;
• A distribution network with metal pipes connecting to the area to be protected;
• Discharge nozzles evenly positioned throughout the protected space.

Typically, the gas system is enslaved by a duly configured and installed fire-detection system.

HOW INERT GAS WORKS

The inert gases work via the total saturation of the environment (Total Flooding), reducing the concentration of oxygen in the protected room to the point where combustion can no longer be sustained (typically around 10-12%).

ADVANTAGES AND DISADVANTAGES

Advantages

• Zero environmental impact, since they are already present in the atmosphere (ODP, GWP, ALT equal to 0);
• After discharge, they do not give rise to harmful decomposition substances when in contact with fire, unlike chemical gases;
• They do not leave residues after discharge, allowing for an immediate resumption of activities;
• They do not cause thermal shocks or fog during discharge, unlike pure carbon dioxide;
• They are electrically non-conductive, hence are suitable for the protection of data processing centres, control rooms, etc.;
• They effectively penetrate every corner of the area;
• Inert gases do not damage the materials with which they come into contact;
• They are quite cheap gases, compared to chemical gases.  

Disadvantages

• They sometimes produce considerable overpressures in the room in which they are discharged, hence they necessitate the installation of an overpressure damper;
• 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;
• Since they lower the oxygen concentration, the presence of people in the environment during discharge must be limited, even though exposure at normal design concentrations is considered safe for a few minutes.

The system design phase is probably the most important. We at Esseci S.r.l. carry this out in compliance with good technical practice, following a series of expedients developed through experience and taking into consideration the specific needs of the client. Furthermore, the hydraulic calculation of the pipes is conducted with software that has been approved and validated with practical testing, as required by the standard.

The activation of a gas extinguishing system is generally controlled by a Fire Detection System that is configured with dual consent activation, to prevent unnecessary extinguishing discharges and to guarantee maximum safety for the personnel.

An inert gas fire-suppression system requires particular testing upon completion of the installation and at predetermined frequencies, in order to verify the air-tightness of the room in which the gas is discharged, being the Door Fan Test.

Furthermore, since the correct maintenance of gas extinguishing systems is of vital importance in order to guarantee their efficiency over time and the maintenance of safety conditions, our company is responsible for providing customers with the complete package of products and services for the professional commissioning and maintenance of fire-suppression systems of this type.