AFS - Foam Presentation PDF

ALTERNATIVE FIRE SUPPRESSION SYSTEMS RESOURCES  POWER POINT PRESENTATIONS  HANDOUTS  NFPA STANDARDS (AVAILABLE ONLINE - SENECA LIBRARIES)  ALTERNATIVE FIRE SUPPRESSION SYSTEMS WITHIN THE LAB REFERENCED CODES/STANDARDS  NFPA 10-STANDARD FOR PORTABLE EXTINGUISHERS  NFPA 12-STANDARD ON C...

ALTERNATIVE FIRE SUPPRESSION SYSTEMS RESOURCES  POWER POINT PRESENTATIONS  HANDOUTS  NFPA STANDARDS (AVAILABLE ONLINE - SENECA LIBRARIES)  ALTERNATIVE FIRE SUPPRESSION SYSTEMS WITHIN THE LAB REFERENCED CODES/STANDARDS  NFPA 10-STANDARD FOR PORTABLE EXTINGUISHERS  NFPA 12-STANDARD ON CARBON DIOXIDE EXTINGUISHING SYSTEMS  NFPA 12A-STANDARD ON HALON 1301 FIRE EXTINGUISHING SYSTEMS  NFPA 17-STANDARD FOR DRY CHEMICAL EXTINGUISHING SYSTEMS  NFPA 17A-STANDARD FOR WET CHEMICAL EXTINGUISHING SYSTEMS  NFPA 2001-STANDARD ON CLEAN AGENT FIRE EXTINGUISHING SYSTEMS CLASS EXPECTATIONS  BE ON TIME FOR CLASS AND PREPARED TO WORK (PPE)  RESPECT EVERYBODY AROUND YOU AND EVERYTHING YOU ARE WORKING WITH  HAVE A CASUAL/OPEN LEARNING ENVIRONMENT (SHARE PAST EXPERIENCES/STORIES THAT RELATE TO FIRE PROTECTION)  BRING A POSITIVE WORKING ATTITUDE TO THE LAB TO GET THE MOST OUT OF IT LEARNING OUTCOME RELATE THE COURSE MATERIAL/THEORY TO THE ALTERNATIVE FIRE SUPPRESSION SYSTEMS THAT ARE AVAILABLE TO US IN THE LAB. BECOME FAMILIAR WITH THE ALTERNATIVE FIRE SUPPRESSION SYSTEMS AND HOW THEY OPERATE.  Foam Systems For years, foam has been used as a fire- extinguishing medium for flammable and combustible liquids. Unlike other extinguishing agents - water, dry chemical, CO2, etc., a stable aqueous foam can extinguish a flammable or combustible liquid fire by the combined mechanisms of cooling, separating the flame/ignition source from the product surface, suppressing vapors and smothering.  It can also secure for extended periods of time against reflash or reignition. Water, if used on a standard hydrocarbon fuel, is heavier than most of those liquids and if applied directly to the fuel surface, will sink to the bottom having little or no effect on extinguishment or vapor suppression. If the liquid fuel heats above 212ºF, the water may boil below the fuel surface throwing the fuel out of the contained area and spreading the fire. For this reason, foam is the primary fire-extinguishing agent for all potential hazards or areas where flammable liquids are transported, processed, stored or used as an energy source.  HOW FOAM EXTINGUISHES A FLAMMABLE LIQUID FIRE: Fire burns because there are four elements present. These elements are heat, fuel, air (oxygen) and a chemical chain reaction. Under normal circumstances if any one of the elements is removed/interfered with, the fire is extinguished. Fire fighting foam does not interfere in the chemical reaction. Foam works in the following ways:  The foam blankets the fuel surface smothering the fire.  The foam blanket separates the flames/ignition source from the fuel surface.  The foam cools the fuel and any adjacent metal surfaces.  The foam blanket suppresses the release of flammable vapors that can mix with air. Method of operation for foam water spray systems  Foam water systems generally work by allowing foam concentrate to mix with water flowing into the piping system. These systems are equipped with a bladder tank containing foam. When a fire is detected a signal is sent to the releasing panel to open the deluge valve allowing water to flow. At the same time, piping to the bladder tank flows and pressurizes the outer shell of the bladder tank which forces foam concentrate to travel into the system piping and then into the Foam Proportioner. The foam solution produced by water and foam concentrate flows into the system piping and is discharged through the open nozzles or sprinklers  Foam water spray systems can be used for discharge of water first, followed by discharge of foam for a pre-determined period, and then followed by water until manual shut off.  Foam Firefighting https://www.youtube.com/watch?v=Jcji0DvxzGE Terminologies Associated with Foam  FOAM: A fire fighting foam is simply a stable mass of small air-filled bubbles, which have a lower density than oil, gasoline or water. Foam is made up of three ingredients - water, foam concentrate and air. When mixed in the correct proportions, these three ingredients form a homogeneous foam blanket.  FOAM SOLUTION: This is a solution of water and foam concentrate after they have been mixed together in the correct proportions.  FOAM CONCENTRATE: This liquid concentrate is supplied from the manufacturer which when mixed with water in the correct proportion forms a foam solution.  FINISHED FOAM: Foam solution as it exits a discharge device, having been aerated.  DRAINAGE RATE: This is the rate at which the foam solution will drain from the expanded foam mass or how long it will take for 25% of the solution to drain from the foam. This is often called the quarter life or 25% drain time. Foam that has a fast drain time is normally very fluid and mobile, spreading across the fuel surface very quickly. While foams with longer drain times are normally less mobile, they move across the fuel surface slowly.  EXPANSION RATE: Volume of finished foam divided by the volume of foam solution used to create the finished foam; i.e., a ratio of 5 to 1 would mean that one gallon of foam solution after aeration would fill an empty 5- gallon container with the expanded foam mass.  LOW EXPANSION FOAM: Foam aerated to an expansion ratio of between 2 to 1 and 20 to 1.  MEDIUM EXPANSION FOAM: Expansion ratio between 20 to 1 and 200 to 1.  HIGH EXPANSION FOAM: Expansion ratio above 200 to 1.  DILUTION RATE, MIXING RATE, OR PROPORTIONING RATE (correct amount of foam concentrate to be mixed with water): The amount is normally shown on the pail or drum of concentrate. The container will normally display a figure or combination of figures. Normal figures shown are 1%, 2%, 3% or 6% or a combination of 1% and 3%, 3% and 3%, or 3% and 6%. If the container of foam concentrate has 3% shown, it means that for every 100 gallons of foam solution required, 3 gallons of the foam concentrate must be used in the solution with the balance being 97 gallons of water.  If 6% were displayed, this would mean that 6 gallons of the foam concentrate would be required to be mixed with 94 gallons of water to form the 100 gallons of foam solution. From the above, it becomes obvious that a 3% foam concentrate is twice as concentrated as a 6% foam concentrate. On the same size and type of flammable liquid fire, half as much 3% foam concentrate would be required than if the 6% foam concentrate had been used.  SEAWATER COMPATABLE: Can foam concentrates be used with seawater as well as fresh water? Modern day foam concentrates can be used successfully with either sea, fresh or brackish water. Types of foam water spray systems Foam water systems are generally divided into the following four (4) categories: - Wet pipe systems - Dry pipe systems - Deluge systems - Preaction systems  Wet pipe spray systems: A sprinkler system employing automatic sprinklers or nozzles that are connected with a piping system that contains water.  Dry pipe spray systems: A sprinkler system employing automatic sprinklers or nozzles that are connected with a piping system that contains air or nitrogen under pressure, the release of which permits the water pressure to open a valve.  Deluge spray systems: A sprinkler system similar to the wet pipe spray system, with the exception of employing open discharge devices.  Preaction spray systems: A sprinkler system similar to the dry pipe spray system with the addition of a supplemental detection system installed in the same area as the sprinklers. Preaction systems are generally used in areas where damage from inadvertent operation of water spray systems must be avoided. Preaction systems generally divide into two (2) groups: single interlock preaction systems and double interlock preaction systems. Double interlock preaction systems require two independent events in order to activate. Firstly, the sprinkler piping loses air or nitrogen pressure due to the operation of one or more sprinklers, and secondly, the solenoid valve is triggered by the operation of a fire detection device. Foam Airport Hangers  https://www.youtube.com/watch?v=wYAOHYKB Yas  https://www.youtube.com/watch?v=4Aoc4ffXlR A Before we review the different types of mechanical foam concentrates, please understand that there are two different basic flammable or combustible fuel groups.  Standard hydrocarbon fuels such as gasoline, diesel, kerosene, jet fuel, etc. These products do not mix with water or are not miscible in water, i.e. these products all float on top of water and, for the most part, they do not intermix.  Polar solvent or Alcohol type fuels are fuels that mix readily with water or are miscible in water. Following is a list of mechanical foam concentrates that are the most common types currently used today.  Aqueous Film Forming Foam (AFFF)  Alcohol Resistant (AR-AFFF)  Synthetic – medium or high expansion types (detergent)  Class “A” Foam Concentrate  Wetting Agent  Fluoroprotein  Protein  Film Forming Fluoroprotein (FFFP)