High Expansion Foam Systems - Chemguard

1 CHEMGUARD204 S. 6th Ave Mansfield, Tx 76063 (817) 473-9964 FAX (817) DATA SHEET #D10D03180 REVISION: 05/2007 high Expansion foam Concentrate and water aremixed in the correct proportion by various methodsto form a foam solution. This solution flows to theHigh Expansion foam Generator (HEFG) with awater powered motor. It is then discharged througha nozzle onto a fine mesh stainless steel screen. Arotating fan (powered by the water motor) in thegenerator forces large volumes of air through thestainless steel screen as the foam solution issprayed onto it. The air mixes with the foamsolution to form a large discharging mass of stablebubbles at a rate of up to 940 gallons of expandedfoam for each gallon of foam solution.

2 This cleanhighly expanded foam mass quickly fills large areasflowing around obstacles and flooding every voidsmothering the fire quickly and output of a Chemguard high Expansion FoamGenerator (HEFG) in a fixed installation depends onwhich generator is selected. These generators areavailable in a wide output range (in cubic feet perminute) at various foam solution inlet multiple units are used an almost limitlessoutput can be achieved. The HEFS is suitable foruse for fire extinction of solid fuel or flammableliquid fires in areas where the expanded foam canbe : Ship holds Aircraft hangars Hazardous material/waste storage areas Flammable liquid packaging areas Flammable liquid drum storage Warehouse areas such as: Rolled paper, tirestorage, in rack storage of combustiblematerials and boat storageHigh Expansion foam Systems have been installedas added protection for Liquid Natural Gas (LNG)facilities where it is used as a fire suppressant andfor controlling vapors released from an accidentalLNG spill.

3 Blanketing spills with high ExpansionFoam is an effective method for reducing andcontrolling fire intensity and decreasing LNG OF EXTINGUISHMENTWhen the high Expansion foam is discharged intoa fire compartment, three extinguishingmechanisms simultaneously large mass of the discharging foam fills allvoids and seals the area involved in the fire andprevents fresh air from reaching the base of theflames. The foam mass maintains an oxygendeficient area until the fire is steam generated is a result of the radiantheat from the fire evaporating the water in thefoam blanket. This conversion to steam absorbslarge quantities of heat and the resulting steam-air mixture is well below the oxygen level that isrequired to support continued cooling effect of the Hi-Ex foam occurs asthe bubbles break and release water onto anyhot surfaces.

4 The surface tension of the drainingwater is lowered and the cooling and wettingeffect of the draining water penetrates any Class A type materials more rapidly than water. Thiscools the burning material to below its high Expansion foam system (HEFS) must bedesigned and installed in strict accordance withNFPA 11 (2002 or later) Standard for Low-,Medium-, and high Expansion foam and anyguidelines established by the "Authority HavingJurisdiction" or Insurance recommends a contractor havingprevious experience in installing fixed fire protectionfoam Systems install the HEFS. Upon installation,the HEFS components should be located andarranged so that any recharging, inspection, testingor general maintenance will cause a minimumHigh Expansion foam SystemsCHEMGUARD204 S.

5 6th Ave Mansfield, Tx 76063 (817) 473-9964 FAX (817) DATA SHEET #D10D03180 REVISION: 05/2007disruption to the fire protection system . The HEFGmay be installed in either a vertical or a mounting a generator in a fixed location, careshould be taken so as not to distort the cylindersection of the generator housing as this couldinterfere with the rotation of the fan/motorassembly. The generator should be supported fromthe bottom not the top and both the front and therear. It is imperative that the generator be firmlybraced to ensure there is no flex or movementwhen the system is in MATERIALSS tainless steel 304, 316, brass, galvanized andblack steel pipe are suitable for use with foamsolutions.

6 The black steel pipe is onlyrecommended for use with foam concentrates whenthe pipe is kept flooded at all times. Stainless steelpipe is suitable for use with foam concentrates at alltimes. Galvanized pipe cannot be used with is recommended that where threaded pipe jointsare in contact with the foam concentrate or thefoam solution, a quality Teflon based pipe joiningcompound and a quality Teflon tape inaccordance with MIL- T-27730 are both used toensure leak tight screw INFORMATIONFor Aircraft Hangars please see the red tab AIRCRAFT HANGARS in this FLOODING system is a fixed foam fireprotection system consisting of the high ExpansionFoam Generators, proportioning system , foamconcentrate, water supply and necessaryinterconnecting piping.

7 This type system isdesigned to discharge the expanded foam into anenclosed space or around the hazard. The totalflood system is suitable for use where there is apermanent enclosure around the hazard that iscapable of holding the required amount of foam forthe designed adequate protection, there should be sufficientfoam concentrate to allow the system a dischargerate sufficient to cover the hazard to an effectivedepth before any unacceptable damage minimum total depth of foam is to be not lessthan times the height of the highest hazardbeing protected but in no case can it be less than 2ft. above that hazard. Submergence time varieswith the type of building construction and if thebuilding has a sprinkler 25: provides maximum submergence timesin minutes for high Expansion foam measured fromthe start of foam discharge.

8 The chart does notinclude submergence times when used on watermiscible/polar solvent type fuels or flammableliquids having a boiling point less than 100 F(38 C). These products may require higherapplication rates. Please check with theengineering department at Chemguard forapplication guidelines. When used in tire storageareas, the submergence time shown reflects thearea also having sprinkler protection. When certaincombustible products are stored 15 feet or higher,fire spread may still be rapid and the dischargetimes in the submergence chart may not besuitable. A faster submergence time may be foam discharge rate is to be sufficient to satisfythe foam depth requirements and submergencetimes allowing compensation for normal foamshrinkage, foam leakage and breakdown effects ofany sprinkler factor for compensation for normal foamshrinkage is compensation factor for loss of foam due toleakage around doors, windows and throughunclosable openings is determined by the designengineer after proper evaluation of the factor cannot be less than Depending onfoam Expansion ratio, sprinkler operation and foamdepth.

9 This factor may be as high as for abuilding with all openings normally factor (Rs) for compensation of breakdown bysprinkler discharge is determined by the followingformula or by test:RS= S X Q whereS = foam breakdown in cfm per gpm of sprinkler discharge. S is to be 10 cfm/gpm ( cu. M/minutes/L/minutes)Q= Estimated total discharge from maximum number of sprinklers expected to operate gpm (L/minutes)CHEMGUARD204 S. 6th Ave Mansfield, Tx 76063 (817) 473-9964 FAX (817) DATA SHEET #D10D03180 REVISION: 05/2007 The following is the formula for calculating theminimum rate of foam discharge or total generatorcapacity allowing for compensation of normal foamshrinkage, foam leakage and breakdown effects ofsprinkler discharge:Formula for CalculatingR(V/T + RS) x CN x CL where.

10 RRate of discharge in m3/min (ft3 / min)VSubmergence volume in m3 (ft3)TSubmergence time in minutesRSRate of foam breakdown by sprinklers in m3/ min (ft3/min)CNCompensation for normal foam shrinkageCLCompensation for leakageAll openings such as doorways, windows, the design filling depth shall closeautomatically before or during foamdischarge whenthe system is DURATION: There shall be sufficienthigh Expansion foam concentrate and water toallow continuous operation of the system at thedesign density for 25 minutes or to generate 4 timesthe submergence volume, whichever is less, but inno case less than enough for a 15 is a typical high Expansion foam Systemfor a building without a sprinkler system :Building: Light Steel, No SprinklersSize: 100 ft.