Since January 1, 2010 diesel engine manufacturers have been required to meet EPA 2010 emissions standards which are among the most stringent in the world. They are meeting these new standards through a variety of ways including the use of selective catalytic reduction (SCR) technology that requires the use of diesel exhaust fluid (DEF) that meets the ISO 22241 standard.
If you are already using DEF, you know that contamination is a big concern. Impurities in the DEF solution can cause premature failure of the catalyst in the SCR system, often voiding the warranty, increasing the amount of DEF used and ultimately requiring replacement which can cost $8,000 to $15,000. Contamination can often be traced back to storage and handling practices. Precautions should be taken to reduce the likelihood of introducing impurities. As little as a tenth of a teaspoon of some minerals are enough to contaminate an entire bulk load of DEF.
DEF is not a fuel but a chemical that needs to be handled differently than fuel is typically handled. DEF should only be stored in stainless steel, coated carbon steel, or specific high density plastic containers in a temperature-controlled location and out of direct sunlight. Each component of the dispensing system, including tank, piping, pump, filter, filling stations, must be used exclusively for DEF in order to prevent cross-contamination; also, DEF will corrode some metals, such as copper and brass. The use of funnels or bottles that have been used for other fluids or refilling previously used DEF containers will not maintain the pharmaceutical-grade purity needed in the SCR system. When filling equipment, we recommend that you also take the time to clean any dust or dirt from around the neck of the DEF tank.
Since DEF is aqueous, it is normal for it to freeze when exposed to prolonged temperatures below 12°F. Freezing is not harmful to DEF and computers governing the engine operation allow equipment to run while the DEF thaws. Some machines are designed with coolant lines running through the DEF tank to speed up the defrosting process. Approved containers used for product storage and on equipment are made to withstand the product expansion that occurs during freezing.
Your local FS energy specialist can help make sure that you have everything needed to keep your DEF pure and contaminant-free during handling and storage. Find your local member company here.