Diesel Exhaust Fluid Best Practices

Vaporex DEF

Diesel Exhaust Fluid Tips


Diesel exhaust fluid (DEF) has become a necessity for most modern equipment. Designed to reduce harmful emissions, DEF works by treating the exhaust gases once they exit the engine, but before they are released into the air. To help you out, we’ve put together some tips and best practices for properly storing and using diesel exhaust fluid.


Why use diesel exhaust fluid?


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.


Storing your DEF


To ensure your diesel exhaust fluid remains as effective as possible, you have to store it carefully. Its average shelf life is about three years, and the ideal temperature range for storage is between 32°F and 86°F. You always want to keep it out of direct sunlight and use plastic or stainless steel containers, as DEF will rust raw steel.


How often to fill your DEF tank


Your heavy equipment most likely has a diesel exhaust fluid gauge built into the dashboard. Just like a fuel gauge, the DEF gauge will show the remaining level of fluid and indicate when it is time to add more. In most pieces of equipment, a series of warnings will let the operator know when the level reaches less than 10%. If your tank has less than 5% of its DEF capacity, the machine power will de-rate. Only enough engine power will remain to move a short distance, so that you can add more diesel exhaust fluid to the tank. Generally, your DEF has to be refilled once for every three to four times you fill up your fuel tank.


What to remember when filling your diesel exhaust fluid tank


The DEF tanks on modern machines are designed so that the opening will only accept a diesel exhaust fluid nozzle. A standard diesel pump nozzle will not fit into a DEF tank opening. The majority of tanks will hold between 15 and 50 gallons of diesel exhaust fluid, depending on the size and horsepower of your equipment. We recommend keeping reserves on hand, as your machine will stop operating once the DEF tank is empty.


Contact our team with any diesel exhaust fluid questions!