Fire extinguisher classes used to distinguish the kind of fire extinguisher. This types based on the classification given to the different types of fires. Fire extinguishers are also color coded. Then, how is a class d fire extinguisher?
This code did because there is no universal fire agent available for all. Several groups can make fire extinguisher is worse than it was. Every classified fire under the British Standard EN-2 for firefighting. Here is seven class of fire extinguisher include class d fire extinguisher:
Water and Foam
Water and foam fire extinguishers put out the fire by taking the elements heat the fire triangle. Foam agent also isolates oxygen from other components.
Water fire extinguishers for Class A fires only. They should not use on Class B or C fires. The exhaust flow can spread flammable liquid in a class B fire, or shock hazards can make on a class C fires.
Carbon dioxide extinguishers
The carbon dioxide fire extinguishers put out the fire by taking the elements of the triangle fire and oxygen also dissipate heat with discharge is very cool. Carbon dioxide can use on a class B fire & c. They usually are not effective on class A fires.
Dry chemical extinguisher
The dry chemical fire extinguisher put out the fire mainly by interrupting the chemical reaction of the fire triangle. Today the most widely used type of fire extinguisher is multi-purpose dry chemical great on class A, B, and C fires. This agent also acts by forming a boundary between the element oxygen and fuel elements on class A fires.
The regular dry chemical is for class B fires & C only. Use the agent could allow a fire to reignite after seems to be successfully extinguished.
Wet chemical extinguisher
The wet chemistry is a new agency put out the fire with the fire triangle dissipate heat and blocks re-ignition by forming a boundary between the element oxygen and fuel.
Wet chemical extinguisher class K developed for advanced high-efficiency Fryer fat in commercial cooking operations. The wet chemical also used on Class A fires in commercial kitchens.
Clean agent fire extinguishers
Halogenated or clean agent fire extinguishers Halon and agent covers the new and less ozone depleting halon agents. They put out the fire by discontinuing the chemical reaction of the fire triangle. Clean agent fire extinguishers are especially for class B fires & c. Some clean agent fire can use on class A, B, and C fires.
Dry powder fire extinguishers or class d fire extinguisher
Dry powder fire extinguishers are dry chemical similar to except that they put out the fire by separating oxygen from the fuel elements or by removing the elements heat the fire triangle. However, the dry powder fire extinguishers are for class D fires, metal or burned only.
Water mist extinguisher
Water mist extinguishers are new improvements that put out the fire by taking the elements heat the fire triangle. They are an alternative to a clean agent fire where contamination is a concern. Water mist extinguishers are fundamentally for class A fires, while safe for use on Class C fires.
How to use a class d fire extinguisher?
Dry powder extinguisher uses a method different than the standard chemical dry. Alternatively of separating the chain reaction to suppress a fire, dry powder extinguishing the fire by forming a barrier between the fuel and air.
Application of agent to the fire must produce a thick blanket, usually at least 1 inch thick over the whole surface of the fuel. Utilization of the agent should be approximately 10 lb/ft² (4.5 Kg/0.9 m2) area most dried powder. Quilts agent trap heat and can develop a crack that will allow air pass allows fuel to continue to burn. Anytime the covers agent is compromised, other agents should be applied to maintain at least 1-inch blanket.
It is critical that the repair delayed until the danger of fuel has enough time to cool below the ignition temperature. It takes 30 minutes or more to help assure that the metal had cooled enough to wiped without the ignition again.
Dry powder “class d fire extinguisher” the most common consists of sodium chloride basis or graphite base with special additives which allow it to flow freely.