Brief Introduction and Selection of Several Major Categories of Fire Fighting Equipment

1. For Class A fires, which involve solid materials such as wood, paper, cotton, and fabric, the appropriate fire extinguishers include water, foam, dry ammonium phosphate powder, and halogenated extinguishers. These fires typically produce burning embers and are common in everyday environments. It's important to choose the right type of extinguisher to ensure effective suppression without causing further damage. 2. When dealing with Class B fires—liquid or meltable solid material fires—dry powder, foam, halocarbon, and carbon dioxide extinguishers are suitable. However, it’s crucial to note that chemical foam extinguishers are not effective against polar solvent fires, such as those involving alcohols, ketones, or esters. This is because the foam breaks down quickly when it comes into contact with these solvents, making it ineffective for fire suppression. Examples of Class B fires include gasoline, kerosene, and ethanol. 3. Class C fires involve flammable gases like natural gas, methane, and propane. Dry powder, halocarbon, and carbon dioxide extinguishers are recommended for these types of fires. It's essential to cut off the gas supply if possible and use the correct extinguishing agent to avoid re-ignition. 4. Class D fires involve combustible metals such as potassium, sodium, magnesium, and aluminum-magnesium alloys. In China, there are currently no standardized Class D fire extinguishers available. However, in other countries, graphite-based powder extinguishers and specialized metal fire dry powders are used. If no proper extinguisher is available, dry sand or cast iron-based foam can be used as a temporary solution. These fires require specific methods due to the reactive nature of the metals involved. 5. Class E fires refer to electrical fires where the equipment is still energized, such as in generator rooms, transformer stations, or computer centers. To safely extinguish these fires, phosphoric acid salt dry powder and halocarbon extinguishers are recommended. Water and water-based agents should never be used, as they can cause electric shocks or further damage. 6. Class F fires occur in cooking appliances involving animal and vegetable oils. These fires must be handled carefully, as using water or foam can cause oil to splatter and spread the fire. The best method is to use an asphyxiation technique, such as covering the appliance with a lid or using a wet chemical extinguisher, to cut off the oxygen supply and suppress the flames effectively.

Carbon Steel Washer

Low carbon USS flat washers, typically used with Grade 8 or hardened steel bolting, are used under bolt heads or nuts to increase the bearing surface area, or to offer protection so that the nut or bolt can be rotated without distortion of the bearing surface. Flat washers are also used to give tightness to a joint, to prevent leakage, and especially to distribute pressure under the head of a bolt or nut. Dimensional specifications are governed by ASME B18.21.1. USS (United States Standard) flat washers have a larger outer diameter than SAE (Society of Automotive Engineers) flat washers, and can be utilized in nearly any application. ASTM F844 covers the standard specifications for unhardened steel flat washers for general use. Available in zinc plated finish. Zinc plating sacrifices itself, corroding before the base material, offering added corrosion resistance.

If you need more information or want to order washers, please contact us.

Carbon Steel Gasket,Zinc Coated Washers,Galvanized Steel Washers,Galvanized Plate Washers

Taizhou Hongchuang Hardware Co., Ltd. , https://www.taizhouhongchuang.com