How Defective Vehicle Fuel Systems Cause Car and Truck Fires
Drivers and occupants of vehicles should not survive a crash only to be burned alive inside the vehicle. However, according to the US Fire Administration, post-crash fires are the leading cause of vehicle-related deaths. These fires ignite for a variety of reasons, including failure to incorporate anti-siphoning valves, failure to include fuel filler tube check valves, misrouting of fuel lines, failure to protect fuel lines, improper placement of the fuel tank inside the vehicle's crush zone and inadequate shielding of the fuel tank.
The Siphoning Defect
Siphoning is simply the flow of a liquid -- gasoline -- caused by pressure between the source of the liquid (the fuel tank) and a discharge point, such as a cut or break in a fuel line. Siphoning can result from either gravity or pressure in the fuel system. Once the siphoning has started, an ignition source as small as a spark will totally engulf the vehicle in flames.
The automotive industry has known for many years that siphoning can contribute to post-collision fires. GM documents dating back to the early 1970s establish that the company knew about the danger and evaluated the cost of incorporating a shutoff valve inside the tank.
If a vehicle caught fire, but the fuel tank was intact, a through investigation must be performed to determine if fuel could have siphoned from the gas tank. Siphoning is an all too common occurrence if no safety features are incorporated into the system.
The Filler Neck Defect
Since every vehicle must be fueled and refueled, every fuel system is designed with a significant hole -- the fuel filler pipe. Auto makers have known since the 1960s that check valves or other safety devices should be incorporated into the filler necks of fuel tanks to prevent the escape of gas during a collision. However, with only a few exceptions, automakers have failed to equip vehicles with these valves, and this defect has led to unnecessary injury and death in collisions.
The U.S. Department of Transportation (DOT) and the National Highway Safety Bureau (NHSB)—the predecessor to the National Highway Traffic Safety Administration—issued a report in 1967 concerning performance standards for fuel-tank protection. The agencies found that it was common for fuel to spill from the fuel-filler pipe in a rollover or other type of crash and concluded that check valves located in the pipe would eliminate spillage.
The concept of a check valve for the fuel-filler pipe is nearly as old as automobiles themselves. Patents dating back to the 1930s refer to these devices. The early patents discuss "flapper valves," which were originally designed to prevent intentional siphoning of gas from the tank. These valves were later designed to stop the flow of gasoline out of the fuel tank in a collision.