The Importance of Pure Diesel Exhaust Fluid
Why is Purity Important?
Contaminated diesel exhaust fluid (DEF) poses risks to your operation. A system using contaminated DEF will consume more of the fluid and be less effective at reducing emissions from the exhaust. Over time this can damage the catalyst in the SCR system, causing the engine to shut down and leaving your team idle in the field. It may also damage your machinery, and the warranty can be voided by the manufacturer if damage is linked back to contaminated DEF.
SCR systems are sensitive to potential chemical impurities in the urea solution, therefore the solvent contains demineralised water. DEF is not classified as a hazardous material but is recommended to be handled with caution; it is corrosive to plant life and most metals.
Due to its corrosive nature, DEF can only be stored effectively in certain materials, such as stainless steel and Polyethylene. If DEF is stored incorrectly it will corrode the surrounding material and in turn contaminate itself. Even a small concentration of trace elements which would otherwise be harmless in fuels and other fluids can contaminate an entire tank of DEF.
Best Practices for Pure DEF
- Make sure the fluid purchased meets the ISO standard by looking for the APIO diesel exhausts fluid certification mark.
- Use a container made for DEF. It should be constructed with materials approved in the standard, and sterilised and sealed properly.
- Maintain and clean, closed fluid path. The standard allows for open systems, but they must be sterlised between each use. This isn’t practical in off-road environments, so closed systems are best used here.
- Keep the work space clean. Dirt and debris near the DEF fill port can also lead to contamination.