Dry powder fire extinguishersPowder fire extinguisher is the most versatile among all types of fire extinguishers used on ships and is suitable for extinguishing gaseous, liquid and solid substances and materials, as well as electrical installations under voltages up to 1000 V. It is convenient to use in small closed or open areas, rooms and compartments. When used on deck, it is worth considering the direction of the wind so that various particles of the extinguishing agent do not enter the respiratory tract.
Powder fire extinguishers are used to extinguish class A, B, C and E fires.
The principle of operation of dry powder fire extinguishers
Fire-extinguishing mixture is pushed out of the cylinder with the help of gas (carbon dioxide, nitrogen or air) at a distance of up to 6 m and tightly covers the fire site and prevents oxygen from entering it, so in that way the combustion stops. The advantage of a dry powder fire extinguisher over, for example, a carbon dioxide is that using dry powder you can release the mixture in portions, depending on the need, thereby affecting the individual fire zones in a targeted manner. The only drawback is that the surface remains hot after extinguishing, so repeated fires can take place again.
Dry powder fire extinguisher usually consists of a cylinder filled with powder (powder types can be different) and gas under pressure up to 16 atm. The pressure inside the cylinder is determined using a built-in pressure gauge. The fire extinguishing mixture enters the hose via a siphon line, and only then enters the sprayer.
The shelf life of a dry powder fire extinguisher, according to normative documents, does not exceed 10 years.