DESCRIPTION AND APPLICATION

The fire suppression systems with chemical fluid fk-5-1-12 (NOVEC 1230) are considered clean agent systems; the norm regulating the use of this extinguisher is the NFPA 2001 edition 2004 and the ISO/DIS 14520-5.

The suppression systems using chemical gas have greatly developed in the last decade when a gradual replacement of Halon 1301 has taken place.
At the moment there are two categories of these systems:

Chemical gases, basically hydro fluorocarbons and similar;
Inert gases such as Argon and Azotes, and a mixture of these also with the addition of carbon dioxide.

These two categories have different characteristics to be carefully evaluated:

A very quick suppression time, but high environmental impacts and long life in the
atmosphere;
Negligible environmental impacts but high operating pressures for inert gases and
considerable space necessary to set the cylinders with release time of 60 seconds
considered very high when a rapid fire suppression is required.

Furthermore the two above categories, with the exception of chemical gas HFC-23 which on the other hand has a highly negative greenhouse effect, have limited security margins and small differences between project and realisation can produce undesired effects on people during the suppression time.

The company 3M has recently developed the NOVEC 1230 fluid that has all the characteristics to avoid the above mentioned inconveniences.

The main features of NOVEC 1230 are as follows:

Deterioration ozone index equal to zero;
Atmosphere life time (ALT) equal to 5 days compared to 29 years of chemical gas
HFC-23;
Potential greenhouse effect (GWP-IPCC) equal to one based on 100 years;
Pressure value of 25 bar, ten times less than the one required for inert gases;
Safety margin between concentration required for fire suppression and the one which could cause adverse effects to
people equal to 69%;
Quantity of cylinders for same volume to be protected 6 times lower than the one needed with inert gases;

Furthermore, since the Novec 1230 fluid at room temperature is in a liquid state, it does not need complex apparatuses for its filling into cylinders nor for its maintenance and refill activities. In fact in case of discharge of the extinguisher, it is sufficient to pour the fluid into the cylinder and pressurize same with a small azote cylinder. This operation can be carried out by a mobile workshop.




The property of NOVEC is to suppress fire by saturation of the room(total flooding). Any equipment at risk and its shape is not affected because there are homogeneous conditions in the room.
Another important factor is the calculation of the quantity of gas to be used in relation to the volume to be protected. The characteristics of the rooms to be protected are important for a good planning of the system and the norms NFPA and ISO 145020 expressly require the Fan Door Integrity Test. The sealing of all openings and the immediate stopping of all ventilation are fundamental for a good result.

In particular, in rooms of small dimensions where many openings exist more or less sealed and from where some gas leakage may occur it is frequent the use of the main release followed by a second maintenance release so as to keep the concentration at the desired level.

As far as the concentration limits for people of NOVEC 1230 gas, reference is made to norm NFPA 2001 and ISO 14520.

For a correct evaluation of the environmental impact, chemical compounds of the decomposition must be taken into consideration.

The Novec extinguisher is suitable in particular for the protection of premises of class A, class A high risk and class B. Typical installations are those to protect computer and telecommunication centres and valuable objects in museums or archives.

NOVEC 1230 fluid is stored in pressurised containers at about 25 bar, connected to a pipe network. At the end of the pipes, discharge nozzles with a calibrated orifice calculated by an accurate software system release the fluid which then vaporises in the protected area.