Wet Chemical

Specifications

1. Type of Fire Classification
   • Class K Fires: Wet chemical fire extinguishers are specifically designed to fight Class K fires caused by cooking oils, fats, and greases. These fires often occur in kitchens, especially when oils are overheated and ignited.
   • Class A Fires: Wet chemical extinguishers can also handle Class A fires (ordinary combustibles like paper, wood, and fabric) due to the cooling properties of the solution.
2. Mechanism of Action
   • Chemical Reaction: Wet chemical fire extinguishers use a potassium-based chemical solution that reacts with the heat of the fire, forming a thick, soapy foam layer that smothers the flames and cools the oil or fat to below its ignition point.
   • Cooling Effect: The wet chemical solution cools the fire source, particularly cooking oils, by lowering the temperature rapidly, which prevents the fire from reigniting.
   • Oxygen Deprivation: The foam blanket formed by the wet chemical agent cuts off the fire’s oxygen supply, suffocating the flames and preventing further combustion.
   • Wet Agent Formula: Wet chemicals are specifically formulated to deal with grease fires, unlike water or foam, which may worsen grease fires by causing splattering and spreading.
3. Design and Construction
   • Body Material: Wet chemical fire extinguishers are constructed from steel or aluminum for durability and resistance to corrosion.
   • Capacity: Common capacities for wet chemical fire extinguishers are 6L, 9L, and 12L, which are suitable for various kitchen sizes and commercial settings.
   • Pressure Rating: These extinguishers typically operate at low pressure, making them safer for use in confined spaces like kitchens.
   • Discharge Time: The discharge time is typically between 8 to 12 seconds, depending on the size of the extinguisher and the type of fire.
   • Nozzle Type: The nozzle is designed to discharge the wet chemical agent in a controlled spray or jet, effectively covering large areas of burning oil or fat.
4. Application and Usage
   • Commercial Kitchens: Wet chemical extinguishers are essential in restaurants, hotels, cafeterias, and food processing plants, where the risk of grease fires is high.
   • Home Kitchens: Small-sized wet chemical extinguishers can be used in home kitchens to protect against accidental grease fires.
   • Catering and Mobile Kitchens: Wet chemical extinguishers are suitable for mobile kitchens, catering services, and food trucks where oils and cooking fats are often heated.
   • Industrial Kitchens: Industrial kitchens in facilities like hospitals, schools, and large institutions require wet chemical extinguishers to ensure fire safety when using deep fryers and other high-heat cooking appliances.
5. Advantages
   • Effective for Cooking Fires: Wet chemical fire extinguishers are specially designed to handle cooking oil fires, making them far more effective than water or CO2 extinguishers.
   • Prevents Re-ignition: The soapy foam layer created by the wet chemical solution prevents re-ignition, ensuring long-term fire suppression even after the extinguisher has been used.
   • Safe for Kitchen Appliances: Wet chemical extinguishers are safer than other extinguishing agents in kitchen environments because they are specifically designed to handle the dangers posed by cooking oils and fats.
   • Versatile: Wet chemical extinguishers are also effective for Class A fires involving ordinary combustibles, such as wood or paper, making them versatile for various types of fire risks.
   • Minimal Water Damage: Unlike water-based extinguishers, wet chemical agents do not cause water damage to kitchen appliances or surrounding areas.
6. Limitations
   • Not for Electrical Fires: Wet chemical extinguishers should never be used on electrical fires (Class C) or flammable liquid fires (Class B) unless the electrical source has been safely shut off, as the wet chemical solution can conduct electricity.
   • Specialized Use: Wet chemical extinguishers are designed specifically for kitchen fires, making them less effective in other environments, such as industrial or outdoor settings.
7. Compliance and Standards
   • BS EN 3: Wet chemical fire extinguishers comply with the BS EN 3 standards in Europe, which regulate fire extinguisher design, performance, and testing.
   • NFPA 10: Wet chemical extinguishers adhere to NFPA 10 standards, ensuring safety, performance, and proper maintenance in commercial and residential kitchens.
   • UL Listed: Many wet chemical extinguishers are UL Listed, ensuring they meet safety and quality standards in the United States.
   • CE Marked: Wet chemical extinguishers for the European market often carry the CE Mark, ensuring they meet EU safety and environmental regulations.
8. Maintenance and Servicing
   • Annual Inspection: Wet chemical fire extinguishers should be inspected annually to ensure proper functionality and that the wet chemical agent has not degraded.
   • Servicing: After use, wet chemical fire extinguishers should be recharged with the appropriate wet chemical agent to restore their fire suppression capabilities.
   • Hydrostatic Testing: Every 5 years, wet chemical fire extinguishers must undergo hydrostatic testing to verify the integrity of the pressure cylinder.