Diesel Exhaust Fluid Best Practices
Diesel exhaust fluid (DEF) has become a necessity on almost every jobsite. Designed to decrease heavy equipment and vehicle emissions, DEF works by treating the exhaust gases once they leave the engine, but before they are emitted into the air. We’ve put together a few tips and basics about diesel exhaust fluid to help you keep your equipment in top shape.
What is diesel exhaust fluid used for?
DEF is created by mixing purified water and urea, a synthetic inorganic compound. The resulting fluid is colorless and non-toxic, but extremely effective at reducing the level of nitrogen oxides in the exhaust of heavy machines. In Selective Catalytic Reduction (SCR) systems, DEF is injected into the exhaust. It then converts the NO2 into nitrogen gas and water vapor, which are both harmless components of air.
How to store DEF
Diesel exhaust fluid needs to be stored carefully to ensure it remains effective. The ideal temperature range is between 32°F and 86°F, and its average shelf life is 3 years. It should be kept out of direct sunlight in plastic or stainless steel containers, as the compound will rust raw steel.
When to fill your tank
Most new pieces of equipment have a DEF gauge built in to the dashboard. Similar to a fuel gauge, the DEF gauge will show the level of remaining fluid and indicate when it is time to refill. In most machines, a series of warnings will alert the operator when the level reaches less than 10%. If your tank has less than 5% of its DEF capacity, the equipment engine power will de-rate. Only enough power will remain to travel a short distance, so that you can add more diesel exhaust fluid to the tank. Typically, DEF needs to be refilled once for every three to four times you refuel with diesel, but this number will vary with operating conditions.
What to know when filling your diesel exhaust fluid tank
The DEF tanks in your machines are engineered so that the opening will only accept a DEF fill nozzle. A standard diesel nozzle will not fit into a DEF tank opening. Most tanks will hold between 15 to 50 gallons, depending on the size and horsepower of your machine. It’s important to keep reserves on hand, as equipment will cease to operate once the diesel exhaust fluid tank is empty.
