When working in a hazardous environment, diesel engine runaway is a dangerous condition that can have fatal consequences. Engine runaway occurs when a hydrocarbon vapor is ingested through the intake of a diesel engine and becomes its uncontrolled fuel source. When this happens, the speed of the engine is no longer controlled by the governor, causing it to speed out of control. If not stopped, the engine can suffer irreparable damage, or even worse, ignite the vapors and explode. Our blog about diesel engine runaway explains this condition in more detail.
How Do You Stop A Runaway Engine?
This video from AMOT’s Ask the Expert series goes into detail about the only proven solution to stop a diesel engine once it has begun to runaway.
When an engine begins to runaway, the most common reaction is to turn off the ignition key and shut off the engine. Unfortunately, this action will prove to be unsuccessful. The engine is now using vapors as it’s fuel source and turning off the key will have no effect. The only viable option at this point is to cut off the air supply to the engine. Luckily, safety devices that cut off the air supply during a runaway situation do exist.
What Are These Safety Devices?
These safety devices are called air intake shut off valves and simply put, they cut off air entering through the intake in the event of a runaway situation. Since diesel engines operate by ingesting clean air through the intake, cutting off the air supply shuts down the engine when removing the fuel supply isn’t an option.
How do Air Shut Off Valves Work?
There are different systems available depending on your engine make and model, but all are designed around the same concept: once your engine enters into a runaway situation, the air intake shut off system will activate either automatically or manually and shut off the air entering through the intake. The systems are typically installed between the engine air filter and the intake manifold as shown below.
Does My Diesel Engine Need One?
Now that you know how an air shut off system operates, it is important to understand which diesel engines should have them installed. Diesel engines used in hazardous environments, like those found in upstream, midstream, and downstream operations, are all at risk for diesel engine runaway and should always be protected. This includes large equipment like fracturing blenders and coiled tubing units and smaller equipment like light towers and generators.
Don’t Wait Until It is Too Late
Air intake shut off systems are the only proven, reliable method to stop a diesel engine once it has begun to run away. Don’t wait until it’s too late to protect your people and equipment from this preventable disaster.
If you would like help selecting the correct valve for your engine, contact AMOT, download our selection guide, or use the filters on our products page.
