Operating diesel engines in hazardous environments is a serious safety risk. A release of flammable gas or hydrocarbon vapor can occur at any time and be drawn into the engine’s air intake. Turning off the ignition will not shut off the engine because it is running on the external fuel source. The diesel engine will continue to accelerate rapidly and runaway.
This situation will lead to dangerous mechanical failure or flashback explosion of the leaking hydrocarbons. Several major accidents have been linked to diesel engine runaway being the source of ignition, usually with fatal and catastrophic consequences.The most effective way of shutting down a runaway diesel engine is with an automatic air intake shutoff valve.