Document NNk9qrDw8roznQqRXb0znkQ8p

FIRE PROTECTION SUPPRESSORS A TYPICAL 1,000 GAUON TANK 2 IGNITION COMMENCING Tms 0 Millisecond* Pressure 0 00 P S I Time 45 Milliseconds Pressure 0 90 P S I Time 50 Milliseconds Pressure 1 30 P SI DETECTOR OPERATES Ttme 35 Mrllrseconds Pressure 0 20 P S I 4 SUPPRESSION COMMENCES Time 40 Mrtlisecorvds Pressure 0 SS P SI Time 55 Milliseconds Pressure 1 65 P S I 8 SUPPRESSION COMPLETE Time 60 Milliseconds Pressure 2 00 PS I Fig. 33-16. Schematic diagram of supression of on explosion In a large cylindrical tank. Courtesy National Fire Protection Association A hot work permit form or tag is gen erally used to administer the program Al though standard forms are available through insurance companies, many plants have de veloped special forms that specifically relate to their individual operation Detailed in formation on hot work permit programs is contained in Industrial Data Sheet 522, "Hot Work Permits," available from the National Safety Counci] Flameproofing wood and fabrics Fireproofing wood Wood cannot be made fire resistive, but it can be treated to retard both the rate of flame spread over its sur face and the rate it contributes fuel to the fire There are two methods for treating wood impregnation and use of fire-retard ant coatings. Water-soluble treatments are not suitable (or exterior use. Fire-retardant coatings are less effective and less permanent than the best pressure impregnation methods, but they do reduce the hazard from small fires in existing structures Only those makes listed by Un derwriters* Laboratories, Inc, should be used Effective impregnation can usually be done only by companies equipped to do this work Fire-retardant coatings on wood should be applied m accordance with the applica tion specifications which produce the de sired degree of reduction of flame spread. They usually have to be renewed at frequent intervals, especially if the wood is exposed to ram or excessive moisture Ready-mixed fire-retardant paint is commercially avail able, but especially mixed preparations can also be made Regardless of the treating method employed, engineering data can be obtained from the supplier of the treated wood or the manufacturer of the treating chemicals Flameproofing fabrics Fabrics cannot be made noncombustible, nor even resistant to "Underwriters' Laboratories, Inc, 207 East Ontario St, Chicago Fire Protection Equipment List 33-28