DEF and SCR Maintenance Tips from the Diesel and DEF Experts

Published On: July 19, 2024Categories: Blog

Diesel Exhaust Fluid, or DEF, is a reality for most diesel engine operators today. Understanding how your SCR system works and the best practices for using Def and maintaining your SCR  system is critical information to have to keep your equipment operating optimally and ensure that you and your company comply with emissions laws. 

Get the latest information on the global diesel fuel shortage and what’s being done about it in this article from Mansfield Service Partners.

Understanding SCR Systems and DEF Use

The SCR, or Selective Catalytic Reduction system, is familiar, at least in name, to just about anyone working with modern diesel engines today. However, a deeper understanding of this diesel exhaust after-treatment system can help you better maintain your diesel engines and keep the SCR system well-maintained and as reliable as possible. 

The SCR is only one part of your diesel emissions control system. First, the engine reduces other pollutants, like particulate matter (PM). The process of reducing PM includes increasing combustion temperatures, which, in turn, raises NOx emissions. NOx is a contributing factor to ground-level ozone, which becomes smog.

Here’s where SCR comes in. The SCR system substantially lowers the NOx emissions in the exhaust through a catalytic reduction process. An SCR system spreads an aqueous solution that contains 32.5% urea in the exhaust stream. 

This solution is known as Diesel Exhaust Fluid (DEF). It’s also called AdBlue and AUS 32 in some parts of the world. Ammonia from the DEF, combined with the catalyst, turns NOx into harmless elements like nitrogen and water vapor. While the SCR system and DEF do complicate diesel engine maintenance somewhat, they are truly an ingenious solution to the NOx problem, and that’s good for us all. 

Avoid SCR System Problems With Routine Maintenance

Inspection and maintenance are familiar terms to anyone working around commercial machinery and equipment. However, you’d be surprised to find that many diesel engine operators neglect to follow the recommended procedures for maintaining their SCR systems. SCR system inspection and maintenance must be added to the list, just as oil and filter changes and lubrication intervals are. 

Here’s a basic rundown of maintenance your SCR and emissions systems should get:

  • Check and Replace the Diesel Particulate Filter (DPF): If you have an SCR system, then you’ve got a DPF too. Check the DPF folder for wear and tear or clogging regularly and replace as needed. If your DPF is really jammed up, consider hiring a professional DPF cleaning service before you tear it out and replace the whole thing.
  • Inspect Your SCR System: Ensure DEF filters are replaced every 200k miles or 6,500 engine hours. Inspect your DEF tank for any signs of contamination. Contaminated DEF can cause excess buildup and other problems. While you’re in there,  you might as well check your DPF and EGR and the rest of the emissions plumbing and exhaust system for any signs of corrosion or leaks. 
  • Monitor Urea Crystal Buildup: Look for any white crystalized buildup. These urea crystals are a common issue in SCR systems. They can form when DEF gets hot enough to evaporate, when DEF is contaminated, or when it is exposed to air too much.
  • Use Quality DEF and Keep Tanks Topped Off: Running out of DEF is a huge hassle. When it runs low enough, engines operate in “limp home” mode, which can ruin your whole afternoon. Easily avoided when you have Mansfield Service Partners delivering your diesel fuel and quality DEF regularly. 

Smart Strategies for Buying DEF

There are a few key things to remember when buying DEF, especially in bulk. The first is quality. Sure, DEF is relatively simple, but your SCR systems are expensive to replace or repair. Take the time to ensure that the DEF you are buying meets the ISO 22241 standard for purity and concentration. When it comes to DEF, quality matters

Another thing to consider is bulk purchasing and delivery. Start by calculating the volume of DEF you use per month or quarter. If you’re not already buying DEF in bulk and having it delivered along with your diesel fuel supply, lubricants, and other essentials, then realizing how much you’ll save is a pretty solid incentive. 

Pro Tips for Safe and Sound DEF Storage

If you’re buying DEF in bulk and having it delivered, you will need to store it somewhere. Even though DEF is mostly water and urea, where you store it makes a difference. You want your DEF to maintain its intended shelf life and stay stable. 

What You Should Know About DEF Storage

Storing your DEF under the right conditions is easy and will help avoid headaches, damaged equipment, or spoiled product. 

Here are the fundamentals of DEF storage:

  1. Optimal Temperature:  DEF shouldn’t be stored in a hot garage or warehouse. If you want it to stay shelf stable, store your DEF between 12°F and 77°F
  2. Proper Containers: DEF should d be stored in sealed, UV-resistant, high-density polyethylene (HDPE) containers.
  3. Avoid Contamination: Have equipment set aside and labeled “For DEF use only.” Nothing made of copper, zinc, aluminum, or brass should come into contact with your DEF supply. 
  4. Think Safety: DEF should be stored in a well-ventilated area, and employees should use protective equipment for eyes and hands when working with DEF. 

Mansfield Service Partners: DEF, Diesel Fuel and Lubricants Delivered

Keeping your business operating at full steam requires organization, action, and materials. Choosing Mansfield Service Partners for diesel fuel supply, lubricants, and DEF delivery ensures you always have what you need when you need it—24 hours a day.  

With over 90 years of experience, Mansfield Service Partners is the name American companies trust for reliable, high-quality diesel fuel and DEF delivery. We have everything from marine diesel to renewable diesel, DEF, and industrial lubricants. Peace of mind is always included, free of charge. 

Contact Mansfield Service Partners for your business today. Reach us at (800) 683-1331 or email any inquiries to info@mansfield.energy