Everything You Need to Know About DEF
Diesel Exhaust Fluid (DEF) is a non-toxic, high purity solution comprised of 32.5% urea and 67.5% de-ionized water for specific use in Selective Catalytic Reduction (SCR) systems, using this fluid in diesel-powered vehicles, such as trucks, buses, and tractors, helps to reduce the amount of nitrogen oxides (NOx) emitted into the air by 90%.
It is not a fuel additive and must be filled into the dedicated Diesel Exhaust Fluid tank on your diesel vehicle.
SCR and DEF are used to convert Nitrogen Oxide (NOx) into harmless Nitrogen and Water molecules. Nitrogen makes up about 78% of the air we breathe.
This technology has the ability to reduce NOx to near zero levels while also providing your fleet with a 3-5% savings on diesel fuel usage.
Selective Catalytic Reduction (SCR) is an exhaust after treatment system that injects a small amount of a chemical called Diesel Exhaust Fluid (DEF) into the exhaust. DEF is mixed with exhaust in the presence of a catalyst turning NOx (oxides of nitrogen – a harmful pollutant that contributes to smog and acid rain) into harmless nitrogen and water vapor.
Exhaust Gas Recirculation (EGR) is another way to reduce NOx formation. In an EGR system, engine exhaust is recycled back through the engine to dilute the oxygen. Almost all engine manufacturers’ use a form of EGR, as it takes both EGR and SCR to achieve near-zero NOx emissions.
The quality of Diesel Exhaust Fluid is extremely important. High quality DEF will be produced and distributed by companies that have demonstrated their domestic expertise in production and distribution. The qualified companies will bear the American Petroleum Institute (API) Certified symbol.
Diesel Exhaust Fluid is affected by both extreme warm and cool temperatures. Product stored for prolonged periods at temperatures above 86°F can begin to lose urea potency. If this occurs, the SCR system will simply dose DEF at a higher rate than the normal 2-4% to compensate for its decreased potency level. In extreme cool temperature, DEF will begin to crystallize at 12°F.
Diesel Exhaust Fluid should be stored out of direct sunlight in a cool, dry, and well-ventilated area. Ideal storage temperatures are between 12° F (11° C) and 86° F (30° C), Optimum storage facilities include garages, warehouses, or storage systems recommended by equipment manufacturers.
The shelf life of DEF is contingent upon ambient storage temperature. When stored between the recommended temperatures, DEF has a shelf-life of one to two years.
Diesel Exhaust Fluid has unique properties making it crucial to use the proper equipment. DEF is stored and dispensed through dedicated containers and systems. We can assist you in developing equipment storage solutions to meet your specific needs.
Diesel vehicles are equipped with heated tanks and supply lines designed to freeze and thaw with no performance issues.
Diesel Exhaust Fluid will remain unharmed if it freezes and thaws. The urea and water will not separate or lose its potency.
If a non-DEF substance enters the Diesel Exhaust Fluid tank, the Selective Catalytic Reduction (SCR) system will recognize a substance other than DEF. The trucks indicator light will then turn on to notify the driver. Whether or not the vehicle requires servicing is dependent on the level of contamination.
Standard diesel fuel nozzles have a diameter of 22mm. Diesel Exhaust Fluid nozzles have been manufactured at 19mm to prevent standard nozzles from being placed into the DEF tank opening. The DEF tank is also easily recognizable due to its blue tank cap.
The amount of Diesel Exhaust Fluid your truck will use is dependent on the size of the truck’s tank and dosing rate chosen by the vehicle manufacturer. DEF tanks range in size from approximately 6 to 30 gallons.
Refueling intervals will depend on the size of your tank. The Diesel Exhaust Fluid consumption rate is between 2-4% of the diesel fuel consumption.
For example, for every 100 gallons of diesel fuel consumed, between 2-4 gallons of DEF will automatically be injected into the exhaust system. A typical diesel truck can go about 300 miles on one gallon of Diesel Exhaust Fluid.
If your vehicle runs out of DEF, you will first experience performance degradation followed by the inability to start the vehicle.
Do not ingest Diesel Exhaust Fluid. If ingested, do not induce vomiting and obtain medical attention. Rinse your mouth out with water, then immediately drink one to two glasses of water. Never give anything by mouth if victim is unconscious or convulsing.
Try to avoid inhalation of Diesel Exhaust Fluid. If strong inhalation occurs and symptoms develop, move to a place to get fresh air. If symptoms persist, you should obtain medical attention.
If Diesel Exhaust Fluid comes in contact with your skin, flush with cool water then wash with soap and water. Obtain medical attention if irritation persists.
If Diesel Exhaust Fluid comes in contact with your eyes, flush with cool water. Remove contact lenses, if applicable, and continue flushing. Obtain medical attention if irritation persists.
Refer to the Diesel Exhaust Fluid MSDS for additional handling procedures.
Diesel Exhaust Fluid has a harmless mild odor due to the ammonia content.
One gallon of Diesel Exhaust Fluid weighs 9.08lbs.
Diesel Exhaust Fluid is corrosive to most metals. Stainless steel is the only metal used in manufacturing DEF pump equipment.
Diesel Exhaust Fluid is classified as a non-hazardous material.
Diesel Exhaust Fluid is not flammable as classified by WHMIS/OSHA criteria. In case of a fire, DEF containers may be extinguished with water.
Small spills may be absorbed with a non-reactive absorbent and placed in suitable, covered and labeled containers. Prevent large spills from entering into waterways, sewers, basements, or confined areas. DEF can be harmful to concrete and masonry. Never return spills back into the original containers for re-use.
Spilled Diesel Exhaust Fluid should be cleaned up as soon as possible.
5 Tips for DEF Winter Preparation
1. Activate and Test Heaters: However don’t overheat the fluid. If able set the thermostat to 40-45 degrees F.
2. DEF Not Dispensing in Cold Conditions: Dip the dispensing nozzle in clean warm water – this allows urea to dissolve & dispense into truck tank.
3. Top-Off Tanks in Extreme Winter Conditions: DEF freezes more easily in small volumes compared to large volumes – leave 7% head space for expansion
4. Do Not Add Anti-Gel or Freeze Inhibitors: Agents & Inhibitros can impede DEF’s function to remove NOx and can also damage SCR system.
5. Bring it Indoors: There’s no harm to the quality or performance if DEF freezes, but it can be annoying.