02e39f42_stem_Risks_of_Alternative_Fuel__Background
[Hazard --Event] Vehicle fire --from fuelsystem leaksdue toimproperinstallation [Consequences] Fires from liquid fuels are limitedby the relatively slowevaporation of the fuel. Forgaseous fuels, this limitationdoes not exist and large firescan develop quickly. [Knowledge] The experience base forinstallations using high pressuregaseous fuels on any given typeor model of vehicle is stillrelatively small. Although CNGvehicles have been operating fora number of years, many weresmall volume conversions ofunique design and theengineering experience gainedwas not necessarily transferredor transferrable to larger fleets. Additional information onconversion kits for CNG is givenin . "Evaluation of Aftermarket Fuel Delivery Systems for Natural Gas Vehicles and LPG Vehicles," by B. Willson,NREL report NREL/TP-420-4892, (1992).. [Background] 
Many CNG vehicles are converted from otherfuels. The experience and skill of those doingsuch conversions is highly variable. Examination of converted vehicles has shownexamples of fuel lines in openings withoutgrommets, fuel lines routed too close to theexhaust system, and CNG tanks that were tooclose to other components. Past experiencehas shown that not all of those personneldoing these conversions are familiar with theprovisions of NFPA-52.
Clean Air Program -- Assesment of the Safety, Health, Environmental and System Risks of Alternative Fuel
Background