Diesel Exhaust Fluid (DEF) is now commonplace – it’s found across industries using diesel powered engines in their equipment – on-highway, off-highway, mining equipment, severe service vehicles, and even consumer diesel powered vehicles. As DEF is a vital part of your engine and exhaust system, it should be treated like you treat all other engine oils – with proper handling procedures and regular testing.
Cleanliness specifications for DEF are extremely stringent. A small amount of metal contaminants such as copper, zinc, chromium, or nickel can contaminate an entire tanker truck of DEF. Trace amounts of these metals and other contaminants (e.g., iron, aluminum, phosphorus) can build up inside the SCR system and create a lot of problems.
DEF Handling Tips
With the wide use of DEF across a variety of industries and its stringent cleanliness specifications, careful consideration should be given to how it is handled and stored.
- Temperature:
- DEF starts to freeze at 12ºF (-11ºC) and can expand up to 7% when frozen. In cold weather, keep tanks that may freeze should be kept at less than full to allow for expansion. While freezing does not change DEF effectiveness, you should ideally store in DEF between 15ºF and 77ºF (-9ºC and 25ºC). Also, urea will decompose if exposed to long periods of direct sunlight.
- If your DEF does freeze DO NOT put additives in the tank. This will throw off the concentration of the fluid and can damage your SCR system. DEF tanks have a heating element that can thaw the fluid.
- Storage and Dispensing:
- On-spec DEF should be stored in dedicated tanks. Avoid switching DEF products in bulk tanks without a thorough cleaning and rinse with distilled or de-ionized water.
- Prevent dirt or debris contamination during transfer from a drum or bulk tank by using a closed loop system designed specifically for DEF versus open systems such as jugs with screw caps. This can also help prevent crystallization due to exposure to air.
- Use dedicated equipment and containers when putting DEF into a tank. Avoid cross contamination from funnels, hoses, or other containers used for other fluids.
- Since DEF has corrosive properties, do not use with brass or copper containers or hardware. Plastic or stainless steel are always best for handling DEF. Pump fittings and components containing zinc, chrome, brass, nickel or aluminum can corrode and contaminate your DEF.
- Follow stringent housekeeping by cleaning any equipment used to dispense DEF with distilled or de-ionized water (not tap water) and followed by a DEF rinse.
- Quality Standards
- Always confirm when purchasing DEF that it meets the required ISO 22241 quality standards for your equipment. Ask your suppliers to provide a “Certificate of Analysis” or quality with every shipment so you can check if the DEF you purchased matches the specifications.
- Shelf Life
- DEF has a shelf life of 12 months (or longer) which varies based on the temperature it’s stored in. Cooler climates, you may get closer to 18-36 months, in warmer climates, may only be 12-18 months. Monitor shelf life closely especially if your storage containers experience extremes in temperature.
DEF Testing and Analysis
Contaminated DEF can create considerable problems for your equipment such as:
- Increased DEF consumption
- Reduced engine efficiency
- Increased exhaust pollution
- SCR system shutdowns and eventual engine shutdowns
- Damage to catalyst (very expensive to replace)
- Void manufacturer’s warranty
Routine DEF testing can help ensure you don’t have microscopic debris in your DEF bulk storage, or in equipment tanks passing through the filter to the DEF pump. Fluid Life offers a variety of laboratory testing options to help protect your SCR system:
- Crystallization Testing
- DEF Delivery and Bulk Storage
- Contamination Testing
- Urea Concentration
Contact us today to learn more.