SCR components critical in modern diesel engines
In the Mid-February issue of Successful Farming,, I covered the basics of diesel exhaust fluid (DEF). I followed up with a brief overview of the components employed in a selective catalytic reduction (SCR) system.
Keep in mind that the SCR is only one part of the emission control system on a modern diesel engine. It can be fitted with a diesel particulate filter (DPF), diesel oxidation catalyst (DOC), exhaust gas recirculation (EGR), or all of these.
The images on this page are from a 2014 Ford F-550 chassis cab truck. Many of the SCR parts are not easily seen on agricultural equipment due to their placement. An on-road diesel will usually have more emission-control complexity than a tractor, but the theory of operation will be the same.
Within the industry, the emission-control package is often engine-specific based upon its propensity to produce nitrogen oxides (NOx) and the EPA standard that needs to be achieved. For this reason, always reference your manufacturer’s literature to determine the exact components and placement for your equipment.