Water Mist Systems

According to the NFPA 750 definition, water mist is a water spray for which 99% of the total volume of liquid (Dv0.99) is distributed in droplets with a diameter smaller than 1000 microns at the minimum design operating pressure of the water mist nozzle.

Most fires are results of pyrolysis and oxidation process. The pyrolysis process happens when energy (heat) is applied to a fuel surface, as the fuel at some point begins to break into flammable gasses (e.g. CH4 = methane).

Oxidation process happens when more energy (heat) is applied to the atmosphere and the flammable gasses. At this point the oxygen molecules found in the atmosphere split and go together with the flammable gas molecules. This process releases energy and is what we see as the fire, flames and heat.

Water mist is a very effective means of fighting fires since it can interfere with both the pyrolysis process and the oxidation process. Water mist attacks a fire by:

  • Cooling the fire
  • Suffocating the fire
  • Blowing out the fire
  • Wetting the fire

Water mist protection systems optimize the quantity of water used, maximizing effective water volume through the distribution of tiny droplets.

The tiny droplets discharged create a large effective cooling surface area of the fire and surrounding volume. The high speed of the droplets means that the mist can penetrate the hot fumes and reach the combustion area.

Compared with conventional systems that use water as an extinguishing agent, damages resulting from discharge are minimized owing to the relatively small amount of water employed.

LPG Fire Australia has a range of VID FireKill low pressure pressure water mist systems to suit almost all risks. Typical applications include:

  • Machinery spaces (generators / transformers / turbines / conveyors)
  • Ordinary hazard (offices / storage areas / meeting rooms / hotels / schools / heritage)
  • Tunnels (road / rail / cable)
  • Data centres (data halls / DRUPS / offices / storage areas / car parks)
  • Marine (machinery spaces / bulge protection / accommodation / RORO)

Water Spray Systems

Where total flood or local application water mist is not suitable or practical we also have a range of lower pressure FM approved medium and high velocity water spray system nozzles. Designed and manufactured by VID Fire-Kill, our water spray systems nozzles are ideal for heavy industrial risks where hydrocarbon fires are a risk and can be used in conjunction with the VID C-EL FM approved deluge valve. Owing to the low pressure at which they function these spray system nozzles can be installed for use in very harsh windy conditions.

The VID Fire-Kill Model MS nozzles are medium velocity water spray nozzles designed for the protection and cooling of tanks, buildings and other structures against hydrocarbon fires. The Model MS nozzles features oversized internal waterways, minimizing the requirements to the water supply quality. The nozzles can be supplied with different K-factors, spray angles and nozzle materials. The nozzles can even be made in NORSOK M-650 approved Titanium Grade 2 material.