FIRE AND FIRE FITTING By Mr. Prashant Sansare
What is mean by fire?
CASE STUDY What Happened? Late one evening, a large storage tank containing a flammable liquid began to overflow. It was not detected until a security guard noticed a strong odor. He immediately called the area operations personnel to report his concern. Two operators responded by driving a truck to the area to investigate. Within minutes, there was a loud explosion and fire. (It is believed that their truck provided the ignition source that caused the initial deflagration and ensuing fires.) It took plant and civic personnel a day and a half to extinguish the fires which moved from one tank to the next. More than a dozen employees were hospitalized and there was significant property damage.
CASE STUDY
CASE STUDY
CASE STUDY How did it start? The tank was being filled but the operators did not know that the automatic tank gauging system AND the high level alarm system had failed. They did not monitor the filling operation closely because they believed that the tank still had plenty of capacity remaining. And, they did not take the security guard seriously or respond promptly when he reported the strong odor since he was new on the job. Like most significant events, a number of things failed all at the same time!
CASE STUDY
CASE STUDY What You Can Do? Transferring flammable liquids is always a risk with potentially significant consequences. Monitor transfers closely so you can detect and respond to spills and leaks early!!!! Never drive into a flammable cloud! Vehicles can provide ignition sources such as a hot engine manifold or muffler. These are often well above the auto-ignition temperature of many flammables. Remember, if a cloud is ignited by the vehicle you are driving, you will have a front row seat and be the center of the explosion. Take every report of an unusual occurrence or odor seriously and respond quickly and thoroughly.
CASE STUDY
CASE STUDY
What is mean by fire?
The Fire Triangle Fire Safety, at its most basic, is based upon the principle of keeping fuel sources and ignition sources separate.
The Fire Triangle Three things must be present at the same time to produce fire: 1. Enough OXYGEN to sustain combustion 2. Enough HEAT to reach ignition temperature 3. Some FUEL or combustible material Together, they produce the CHEMICAL REACTION that is fire Take away any of these things and the fire will be extinguished
Fuel Classifications Fires are classified according to the type of fuel that is burning. If you use the wrong type of fire extinguisher on the wrong class of fire, you might make matters worse. Its very important to understand the four different fire (fuel) classifications
There are 4 classes of fire: Class A Ordinary combustibles or fibrous material, such as wood, paper, cloth, rubber, and some plastics. Class B Flammable or combustible liquids such as gasoline, kerosene, paint, paint thinners and propane. Class C Energized electrical equipment, such as appliances, switches, panel boxes and power tools. Class D Certain combustible metals, such as magnesium, titanium, potassium, and sodium.
To Prevent Fires Class Ordinary Combustibles: Keep storage and working areas free of trash. Place oily rags in covered containers.
Class Flammable liquids or gases: Don t refuel gasoline-powered equipment in a confined space, in the presence of an open flame, or while the equipment is hot. Keep flammable liquids stored in a tightly closed container and away from spark producing sources. Use flammable liquids only in well ventilated areas.
Class Electrical Equipment: Never install a fuse rated higher than specified for the circuit. Investigate any appliance or electrical equipment that smells strange. Unusual odors can be the first sign of a potential fire.
Class Flammable metals: Knowledge of the properties of the metals and using good judgment and common sense will assist you in controlling or avoiding potential fires/reactions.
Fuel Classifications Most fire extinguishers will have a pictograph label telling you which types of fire the extinguisher is designed to fight. For example, a simple water extinguisher might have a label like this which means it should only be used on Class A fires.
Types of Fire Extinguishers Different types of fire extinguishers are designed to fight different classes of fire. The 3 most common types of fire extinguishers are: 1. Mechanical Foam type (AFFF) 2. Carbon Dioxide (CO 2 ) 3. Dry Chemical (ABC, BC, DC)
Types of Fire Extinguishers 1. Mechanical Foam Fire Extinguishers What is foam? an aggregate of air-filled bubbles formed from aqueous solutions which is lower in density liquids used than flammable liquids. It is principally to form a cohesive floating blanket on flammable and combustible liquids, and prevents or extinguishes fire by excluding air and cooling the fuel. It also prevents reignition by suppressing formation of flammable vapors. It has the property of adhering to surfaces, which provides a degree of exposure protection from adjacent fires
Types of Fire Extinguishers 1. Foam Fire Extinguishers Foam extinguish fire by taking away the Oxygen & heat element of the Fire Triangle.
Types of Fire Extinguishers 1. How foam works: Foam can: Exclude oxygen from fuel vapors Cool fuel surface with water content of foam Prevent release of flammable vapors from fuel surface
Types of Fire Extinguishers What is foam not effective on?: Foam is not effective on Class C electrical fires: Foam contains 94 97% water & water conducts electricity Class C fires can be extinguished using nonconductive extinguishing agents
Types of Fire Extinguishers 2. Carbon Dioxide Fire Extinguishers The pressure in a CO 2 extinguisher is so great, bits of dry ice may shoot out of the horn! CO 2 cylinders are red. They range in size from 5 lbs to 100 lbs or larger. On larger sizes, the horn will be at the end of a long, flexible hose.
Types of Fire Extinguishers 2. Carbon Dioxide Fire Extinguishers CO 2 s are designed for Class B and C (Flammable Liquids and Electrical Sources) fires only! CO 2 s will frequently be found in laboratories, mechanical rooms, kitchens, and flammable liquid storage areas. In accordance with NFPA regulations (and manufacturers recommendations), all CO 2 extinguishers are needs to undergo hydrostatic testing and recharge every 5 years.
Types of Fire Extinguishers 2. Carbon Dioxide Fire Extinguishers Carbon dioxide is a non-flammable gas that takes away the oxygen element of the fire triangle. Without oxygen, there is no fire. CO 2 is very cold as it comes out of the extinguisher, so it cools the fuel as well.
Types of Fire Extinguishers 2. Carbon Dioxide Fire Extinguishers A CO 2 may be ineffective in extinguishing a Class A fire because it may not be able to displace enough oxygen to successfully put the fire out. Class A materials may also smolder and re-ignite.
Types of Fire Extinguishers 3. Dry Chemical (ABC) Fire Extinguishers Dry chemical extinguishers put out fire by coating the fuel with a thin layer of dust. This separates the fuel from the oxygen in the air. The powder also works to interrupt the chemical reaction of fire. These extinguishers are very effective at putting out fire.
Types of Fire Extinguishers 3. Dry Chemical (ABC) Fire Extinguishers ABC extinguishers are red. They range in size from 5 to 20 lbs. ABC fire extinguishers are filled with a fine yellow powder. The greatest portion of this powder is composed of monoammonium phosphate. The extinguishers are pressurized with CO2.
Types of Fire Extinguishers 3. Dry Chemical (ABC) Fire Extinguishers Dry chemical extinguishers come in a variety of types You may see them labeled: DC (for Dry Chemical ) ABC (can be used on Class A, B, or C fires) BC (designed for use on Class B and C fires)
Types of Fire Extinguishers 3. Dry Chemical (ABC) Fire Extinguishers It is extremely important to identify which types of dry chemical extinguishers are located in your area! An ABC extinguisher will have a label like this, indicating it may be used on Class A, B and C fires. You don t want to mistakenly use a BC extinguisher on a Class A fire thinking that it was an ABC extinguisher.
10 Tips on How and When to Use a Fire Extinguisher 1 Most fires start small. Except for explosions, fires can usually be brought under control if they are attacked correctly with the right type and size of extinguisher within the first 2 minutes! 2 A fire extinguisher should be "listed and labeled" by an independent testing laboratory. The higher the rating number on an A or B extinguisher, the more fire it can put out. Be careful, high-rated units are often heavier models. Make sure you can hold and operate the model you are using.
3 Before attempting to fight a small fire, be sure everyone is out of the area. Ensure someone has called the fire department. If the fire starts to spread or threatens your escape path, get out immediately! 4 The operator must know how to use the extinguisher quickly without taking time to read directions during an emergency. Remember that the extinguishers need care and must be recharged after every use.
IF YOU FIGHT A FIRE, REMEMBER THE WORD P A S S PULL... AIM... SQUEEZE... SWEEP 5 PULL... the pin. Some extinguishers require releasing a lock latch, pressing a puncture lever or other motion. 6 AIM... low, pointing the extinguisher nozzle (or it's horn or hose) at the base of the fire.
7 SQUEEZE... the handle. This releases the extinguishing agent. 8 SWEEP... from side to side at the base of the fire until it appears to be out. Watch the fire area in case fire breaks out again, and repeat use of extinguisher if necessary. 9 Read and follow the directions on your extinguisher. If you have the slightest doubt about whether or not to fight a fire DON T! Get out and close the door behind you.
How to Use a Fire Extinguisher It s easy to remember how to use a fire extinguisher if you remember the acronym PASS: Pull Aim Squeeze Sweep
How to Use a Fire Extinguisher Pull the pin This will allow you to discharge the extinguisher
How to Use a Fire Extinguisher Aim at the base of the fire Hit the fuel. If you aim at the flames... the extinguishing agent will fly right through and do no good.
How to Use a Fire Extinguisher Squeeze the top handle This depresses a button that releases the pressurized extinguishing agent.
How to Use a Fire Extinguisher Sweep from side to side.. until the fire is completely out. Start using the extinguisher from a safe distance away, then slowly move forward. Once the fire is out, keep an eye on the area in case it reignites.
Be prepared for a fire emergency Check the location of fire alarms and know how they work. Learn your building evacuation plan. Know where your two nearest exits are located. Learn how doors swing and where stairs lead. Make sure nothing blocks fire pulls, extinguishers and emergency exits. Learn the sound of your building fire alarm. Post emergency numbers (including security and first aid) near your telephone. Make sure you know what to do if the fire alarm sounds. Plan your escape.
When you hear the fire alarm: Leave at once, taking direction from the emergency warden. Do not delay yourself by gathering personal items. Your safety always comes first. Before you open any door, feel the door with the back of your hand. If the door is cold, slowly open it a crack. If there is no smoke in hallways or stairwells, follow your building s evacuation plan. Get out quickly using designated fire exits.
When you hear the fire alarm (continued): Close doors behind you, however do NOT lock the door. Locking the door hinders the fire department s search and rescue efforts. The stairway will be your primary escape route. Never, never use elevators under any circumstances. Once in the stairway, proceed down to the first floor and out of the building. Never go up.
If you are trapped in smoke or heat: Before you open any door, feel the door with the back of your hand. If the door is warm to the touch, DO NOT attempt to open the door. Stuff the cracks around doors with towels, rags, clothing or tape, and cover vents to keep out smoke. Stay low to the floor, and if possible, cover your mouth and nose with a damp cloth or dust mask to help you breathe. If there is a phone in the room where you are trapped, call the fire department to tell them exactly where you are located. Do this even if you see fire apparatus on the street below.
If you are trapped (continued): Wait at a window and signal for help. Do not panic or jump!! WAIT! If possible, open the window at the top or bottom, but do not break it, you may need to close the window if smoke rushes in. Be patient. Rescuing all the occupants of a building can take several hours.
After a fire emergency: Once you are out of the building, STAY OUT! Do not go back inside for any reason. Report to your warden for roll call at your designated assembly point. Tell the fire department via your warden if you know of anyone trapped inside the building. Only re-enter if and when the fire department tells you it is safe to do so.
In the event of a fire, your personal safety is your most important concern.
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