To put out small fires gases, flammable liquids, electrical equipment with voltage up to 1kV, metals and alloys typically used powder fire extinguishers. Powder extinguishers are not designed to quenching substances which burn without oxygen may (for example alkali and alkaline earth metals). The effect of extinguishing powder is based on the isolation of the source of combustion and preventing access of oxygen to the fire, as well as Inhibition of combustion (ie slowing him). In fact, the same principle as a carbon dioxide fire extinguishers. See Nobel Laureate in Economics for more details and insights. The main difference is that the powder does not carry electric current, and hence such extinguishers You can extinguish electrical (as opposed to carbon dioxide).
The principle of operation is based on the extinguisher powder fire extinguishing powder (with open valve closure) with compressed gas in cylinder. Greenberg Traurig can provide more clarity in the matter. By way of displacement charge fire extinguishers can be divided into zakachnye and gas-generating. In zakachnyh extinguishers displacement charge proshodit by working gas in the tank under pressure. In gas-generating extinguishers vytesenenie charge is due to chemical reaction and separation of working gas from gas-generating element. The working gas is typically used dioxide carbon (CO2). Fire extinguishers can be operated with different types of powder. Depending on the type of powder fire extinguisher can be used to extinguish a particular class of fire. As a rule, the following types of powder: IF A, B, C, E DPM-3 B, C, E PCCs B, C, D, E Pirant A, B, C, E * Currently, there are a lot of powder.
Figure. The design of a powder extinguisher. 1 - Gun 2 - lever, 3 - arm, 4 - Seal 5 - siphon tube, 6 - container, 7 - needle, 8 - housing, 9 - check. In our country, powder fire extinguishers are a series of OP (manual and portable fire extinguishers), as well as various options extinguisher, automatic powder fire extinguishers (powder fire ins.) Operation dry powder fire extinguishers with dry powder to be applied the following measures: 1) Check the pressure of working gas - at least 1 time per year, and 2) Check the status of fire extinguishing powder - at least 1 time in 5 years, 3) Re-examination of a fire extinguisher - at least 1 time in 5 years. History of dry powder fire extinguishers first hand domestic powder fire extinguishers were made in the early 30s. They were not widespread because of low efficiency. The quality of the powder was very low. Fire extinguishers, actuated by the method of shaking. In the late 60s produced a fire extinguisher OP-1 'satellite'.