Parts + Service

Everything You Wanted to Know About DEF

Modern, environmentally-friendly engines use multiple systems to reduce diesel truck exhaust emissions. One such system uses Select Catalytic Reduction (SCR) technology and Diesel Exhaust Fluid, or DEF.

TRP CleanBlue® DEF is designed and tested specifically for today’s SCR systems, providing a fuel-efficient and cost-effective solution to 2010 EPA regulations for truck owner operators and Kenworth fleets. It’s a non-toxic, non-polluting, non-hazardous and non-flammable DEF solution that can be used in all SCR after treatment systems, regardless of engine manufacturer.

Here are some answers to the most frequently asked questions about DEF:

  • What type of vehicles need DEF? Heavy- to light-duty vehicles with newer engines that use SCR technology need DEF.
  • Why is DEF required? DEF eliminates harmful exhaust emissions so engines meet Environmental Protection Agency (EPA) standards.
  • How does DEF work? Once injected into the hot exhaust gas stream, DEF vaporizes & forms ammonia and carbon dioxide. Then, with help from the SCR catalysts, the ammonia converts nitrogen oxide to harmless nitrogen and water.
  • Why is the quality of DEF important? It is important to maintain the concentration and purity of DEF ingredients so the SCR system functions properly and lasts longer.
  • What packages does DEF come in? TRP CleanBlue® DEF comes in 2.5 gallon jugs, 55 gallon drums, and 275 or 330 gallon totes. Make sure you are using a “closed system” such as provided by TRP to prevent contamination.
  • How do I know the DEF I purchase will work? DEF products should display the American Petroleum Institute (API) certification standards & ISO 22241-1 specifications for purity and composition.
  • How much DEF will I use? Use approximately 2 gallons of DEF per every 100 gallons of diesel fuel, depending on vehicle operation, duty cycle, etc.
  • Does DEF require special handling? No, DEF is non-toxic, non-polluting, non- hazardous and non-flammable. It is safe to handle and store, and poses no serious risk when handled properly.
  • How should DEF be stored? DEF should be stored in a cool, dry, well-ventilated area and out of direct sunlight. Optimum storage temperature is 77° F (25°C).
  • Is DEF stable? Shelf life can be in excess of one year when stored in moderate temperatures. In either hot or cold extremes shelf life can degrade to six months.
  • What happens if DEF freezes? A 32.5% DEF solution, comprised of urea & water, will begin to crystallize & freeze at 12° F (-11° C). Urea & water freeze at the same rate, ensuring that as it thaws, the fluid does not become diluted or over-concentrated.

For more information on TRP CleanBlue DEF and other emission-reducing technologies, visit your preferred Kenworth dealer.

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