What is water mist?
Water mist is a suppression system that uses high pressure water to create a fine mist to suppress fires which is a versatile and highly efficient fire protection solution, unique nozzles have been designed and tested to protect against a range of fire risks. The mist generated by the system can extinguish fires or limit its growth from an early stage depending on the asset being protected. Water mist systems help provide effective cooling and fire control.
To be able to combat a fire efficiently you need to be able to remove the 3 elements that create a fire: oxygen, fuel and point of ignition. A Water mist system instantly cools and disperses the oxygen around the fire to suppress the fire at the point of ignition. A High-pressure water mist system increases the speed of which the water mist is dispersed which removes the energy from the fire faster resulting in less damage.
Water Mist systems are categorised into high and low pressure. A high-pressure system will operate at a maximum pressure of 200bar whereas a low-pressure system will operate at a maximum pressure of 16bar. Both a wet pipe and deluge system can operate of either high or low pressure.
What are the benefits?
There are many benefits to choosing a water mist system. A water mist system requires less stored water and smaller equipment which allows for cleaner and smaller storage areas, Water mist also causes less damage due to the reduced water being discharged by system activation. Water mist causes less risk to your workforce because it does not use gas in its system which eliminates the risk of asphyxiation.
A Deluge System works in combination with a separate detection unit, if a fire is detected water is sent through the system to supress the fire. A Deluge system only uses open nozzles which means when the water is sent through the system it discharges from every open nozzle.
An automatic system works independently, each nozzle contains a glass bulb. The heat from a fire will burst the glass bulb which releases the water from the pressurised system supressing the fire. The breaking of the bulb will initiate the pump system that will then send further water through the system to maintain pressure.
A dry pipe system is used in areas that would be problematic for a water filled system, A typical use for a dry pipe system would be in an environment with freezing temperatures or an area at significantly high risk of damage. Instead of water the pipe is filled with air, when the nozzle opens at the detection of a fire the air pressure in the pipe drops which initiates the pump system to then send water through the pipework to the nozzle. This system would require a compressor to maintain the pressure of the air in the pipe.
A pre-action system is used in conjunction with an alternative fire detection system. If a fire is detected the section valve will open which initiates the water mist system sending water to the corresponding area. The heat from the fire will open the activated nozzle which sends water to the location of the fire and not all nozzles in the zone.
High Pressure water mist systems can be supplied in two different formats. One system requires both nitrogen and water cylinders whereas the other just requires a pump set and water tank. The use of a particular type will depend on the type of asset you are protecting, the coverage area, the environment, and the duration of dispersion to combat the fire. Both systems are suitable for use on either Class A or B fires. All pipework and fittings used to install a high-pressure system are constructed with 316 stainless steel to stop corrosion and contamination.
A low-pressure water mist system requires a pump set and water storage tank. The rate of which the water is dispersed is dramatically lower than a high-pressure system.
A low-pressure water mist system uses less water than a conventional sprinkler system, this reduces the damage and protects your asset.
A low-pressure water system is effective on Class A and B fires.
The pipework for a low-pressure system is small and compact, all our engineers are trained in the installation of stainless-steel pipework using press fit crimp joints.
Cylinder systems require less space than pump systems, this is because you only require Nitrogen and water cylinders that are connected via a manifold and not a pump set. When a cylinder system electronically or manually activated the Nitrogen will enter the water cylinder to create the high-pressure water that will then discharge high pressure mist from the activated nozzle. A cylinder system will have a static pressure of 200bar which then drops when activation occurs. All cylinder systems or pressure vessels need to be tested or replaced after 10 years; FGS can test the quality of the cylinders using a method called hydro-static testing.
FGS have the capability to provide you with fire suppression solutions for all environments, we offer service, design, and installation.
FGS are equipped to offer maintenance services to gas suppression systems which protects your equipment, asset and safeguards the future of your business and safety of your employees.
If you require an automatic suppression system that requires no electrical power, then a Flexitec system would meet your needs. Flexitec is an automatic fire suppression system that uses a pressurised 6mm tube. On contact with fire the tube bursts decreasing the line pressure. When the pressure decreases the cylinder valve will open sending a mix of nitrogen and water through the 6mm tube to the burst point. This type of system can be fitted as a direct system or an indirect system. Different extinguishing products can be offered to protect the required asset.
