Understanding the Difference Between Water and Dry Fire Extinguishers
Before delving into the differences between water and dry fire extinguishers, it's important to understand that both types of extinguishers play crucial roles in fire safety and might be used in different scenarios based on the nature of the fire.Overview of Fire Extinguishers
Fire extinguishers can be categorized based on their agent and the types of fires they are designed to combat. Two of the most common types are water extinguishers and dry chemical powder (DCP) extinguishers. Understanding their unique characteristics can help in choosing the right tool for the job.Difference Between Water and Dry Extinguishers
Water extinguishers and DCP extinguishers are equipped with different agents that are designed to combat various types of fires. Here’s a detailed comparison to help you understand when and how each type might be effective.Water Extinguishers
Water extinguishers are primarily used for Class A fires, which involve solid combustibles such as paper, fabric, and wood. These extinguishers work by cooling the flames, thus helping to extinguish the fire. They are often red in color and have a Class A rating on the label. Contrary to their name, modern water extinguishers are often pressurized deionized water systems.Water Extinguishers (Class A)
- Rating: Class A - Color: Red - Agent: Deionized water - Use: Fires involving solid combustibles. Water helps to cool the flames and effectively extinguish the fire.Types of Water Extinguishers:
1. Geefer or PW (Powder Water): This is a pressurized deionized water extinguisher. While less common today, they were once widely used, especially in the context of manual hand pump systems. 2. Hand Pump Systems: Hand pump fire extinguishers, often referred to as "can man" by the New York Fire Department (NYFD), were particularly popular in the past for manual firefighting efforts. These systems are pressurized water extinguishers that require manual operation.Dry Chemical Powder (DCP) Extinguishers
Dry chemical powder extinguishers (DCP) are more versatile and are used for Class A, B, and C fires. These extinguishers are labeled with a blue label and come with a rating to indicate their range of applications. DCP extinguishers are commonly used for fires involving liquids, gases, and electrical equipment.Dry Chemical Powder (DCP) Extinguishers (Class A, B, C)
- Rating: Class A, B, and C - Color: Blue - Agent: Dry chemical (usually monoammonium phosphate or potassium-based powder) - Use: Fires involving solid, liquid, and gas, as well as electrical fires.Types of DCP Extinguishers:
1. Purposely Pressurized Systems: The dry chemical powder is poured into the extinguisher and the valve is reattached. The extinguisher is then pressurized with an inert gas like nitrogen. 2. Potassium Extinguisher: A specifically designed extinguisher known as a "Purple K" potassium-based powder extinguisher uses a gas cartridge that pressurizes the extinguisher when activated by the user. Always ensure that the cap is tightly secured before applying pressure.Alternate Systems: Some DCP extinguishers use a gas cartridge system, such as the Purple K, which pressurizes the extinguisher more efficiently. This ensures a consistent flow of the powder agent during fire suppression.
Additional Fire Extinguisher Types
While water and DCP extinguishers are the most common, there are other types of fire extinguishers designed for specialized situations. These include foam, carbon dioxide (CO2), and halon extinguishers, each designed to handle specific types of fires.1. Foam Extinguishers: Often used in industrial settings near special processes or for specialized applications. They are less common in residential or general settings.
2. Gas Extinguishers (CO2): These are particularly useful around electrical equipment. CO2 has the advantage of not leaving a residue, making it ideal for confined spaces or areas where electronic equipment is present. Commonly found in race tracks, auto repair shops, and other similar environments.
3. Portable Halon Extinguishers: While rare today due to their potential to deplete the ozone layer, portable halon extinguishers are still used in certain high-risk applications. They displace air, making the environment inhospitable for the fire, but the operator must be careful not to breathe the gas.
Fixed Halon and CO2 Systems: These systems protect high-value equipment in enclosed spaces. While effective, they require careful planning and maintenance to ensure they function correctly.