Description and Applications

The implants of quenching fluid chemical fk-5-1-12 (NOVEC 1230 ®) – Dodecafluoro 2 methylpentan-3-one are to be considered of the clean agent systems; legislation that oversees the use of this extinguisher is the NFPA 2001 – Edition 2004 and ISO / DIS 14520-5.
Systems shutdowns chemical gas fire, in the last decade, since it is carried to the gradual replacement of Halon 1301, have suffered a great evolution. Are currently available on the market two categories of products put to use on plants have both characteristics to be assessed off:

  • chemical gases, hydrofluorocarbons and substantially similar
  • The inert gases, consisting of Argon, Nitrogen, mixtures of the same, even with the addition of carbon dioxide.

NOVEC The two categories are both characteristics to be assessed carefully:

Tempo di spegnimento molto rapido, 10 secondi, ma elevati impatti ambientali per i gas chimici, oltre alle problematiche, per alcuni di essi, relative al loro tempo di permanenza in atmosfera, prima della loro decomposizione;
Impatti ambientali pressoché nulli, ma elevate pressioni di esercizio in gioco per i gas inerti, oltre al notevole spazio necessario per alloggiare le bombole di contenimento ed al tempo di scarica di 60 secondi, molto elevato in caso di richiesta di interventi di spegnimento rapido.

Inoltre, entrambe le due categorie di prodotti estinguenti,, ad eccezione del gas chimico HFC-23, che peraltro ha i piú alti valori negativi di effetto serra e di vita media nell’atmosfera, presentano dei margini di sicurezza molto limitati tra la concentrazione di spegnimento richiesta e la concentrazione alla quale non si riscontrano effetti avversi sulle persone; ció comporta che anche minime discrepanze difficilmente valutabili tra i dati di progetto e di ingegneria rispetto all’impianto installato potrebbero essere gravemente penalizzanti per la corretta realizzazione del sistema si spegnimento.

La societá 3M ha recentemente presentato il NOVEC 1230 ®, un fluido da utilizzare in impianti di spegnimento che ha tutte le caratteristiche per ovviare agli inconvenienti di cui sopra, tipici degli impianti di spegnimento con estinguente a gas chimico o inerte.
Le principali caratteristiche del NOVEC 1230 ® sono:

Indice di deterioramento ozono pari a zero;

  • Index ozone deterioration zero
  • lifespan in the atmosphere (ALT) equal to 5 days, compared, for example, to 29 years in chemical gas HFC 125 extinguishant
  • value of global warming potential (GWP – IPCC) equal to one, referring to the 100 years
  • pressure pressurization equal to 25 BAR, about ten times lower than that required to inert gases;
  • margin of safety between the extinguishing concentration and the one to which you may experience adverse effects on people 69%.
  • Quantity of cylinders required in equal volume to be protected less than about 6 times that required for the inert gases;

In addition, another fundamental element ‘that, as the fluid NOVEC 1230 ® at room temperature in the liquid phase does not require for its transfer in bottles of expensive and complicated equipment, both for business and for those maintenance charging. In fact in case of discharge of the extinguishant, will be sufficient to pour the fluid in the cylinder and repressurize the same with a small cylinder of nitrogen, an operation that can be safely performed with a mobile workshop.

Table A – Environmental characteristics of NOVEC 1230 ® compared to those of HFC-125 NOAEL – LOAEL – MARGIN OF SAFETY
Table B – Concentration shutdown and safety for the people of NOVEC 1230 ® compared to those of HFC-125

The principle of operation of the extinguishing fluid NOVEC 1230 ® is that of saturation of the environment (total flooding); this system of operation has the great advantage of not having to worry about the location of the risk materials, nor their conformation because it creates conditions homogeneous throughout the environment.

Another essential parameter is the evaluation of the volume to be protected in order to fix the amount of gas to be used. The characteristics of the environment to be protected are fundamental for a correct design of the system, so that the NFPA and ISO 145020 expressly provide leak test called Fan Door Integrity Test, and the closure of all openings with automatic frames and l ‘ immediate shutdown of ventilation systems are critical to the effectiveness of the system.

In particular small areas where there are numerous openings more or less sealed, where can exit the extinguishing gas, it is common to use the main discharge systems and maintenance. After the first burst main, followed by a download additional “keep “, just to keep the concentration in the concentration range required for shutdown.

With regard to the limits of concentration and exposure of humans to the smothering gas NOVEC 1230 ® refers to the provisions of NFPA 2001 and ISO 14520.

For an assessment of the compatibility of the extinguishing fluid NOVEC 1230 ® with the environment must consider the interaction determines that the gas in contact with the flame and the resulting products of the chemical decomposition. The extinguishing fluid NOVEC 1230 ® fact to the contact with the flame and produces heat produces hydrofluoric acid (HF) in small amounts, however, are not harmful to humans and to the equipment, in line with the values ​​expressed by the other fire extinguishing agents chemical.

The proliferation of new type of clean agent fire extinguishing gas Inert gas Haloncarbons and led the NFPA 2001 to introduce a new testing protocol compatibility of the toxicological called PBPK – Physiologically Based Pharmacokinetic Model, which considers the maximum permissible concentration in the blood of ‘ extinguishing agent and the time needed to reach it.
This extinguisher is suitable for the protection of those at risk of fire, Class A, Class A and Class B high risk Typical installations are in the protection of computer centers electronic and telecommunications equipment or high-value items in museums or archives.
In summary, the extinguishing system in extinguishing fluid NOVEC 1230 ® consists of pressurized cylinders approx. 25 bar, connected to a system of pipes that deliver to destination. The extremity of said pipes there are the discharge nozzles with calibrated orifice, calculated through an accurate calculation software dedicated, through which the fluid in the gaseous phase is discharged into the room to be protected.