Definitions of Aftertreatment (ATS) Terms

57X mm 49.01.002

Refer to the following list of definitions of ATS terms and components.

  • Aftertreatment System (ATS)—the entire exhaust system from the turbocharger to the exhaust stack or tail pipe.

  • Aftertreatment Device (ATD)—a housing that contains the DOC and DPF (also the SCR and the mixing tube in one-box systems).

  • Diesel Particulate Filter (DPF)—a component in the ATD that traps soot from the exhaust gas.

  • Diesel Exhaust Fluid (DEF)—the chemical agent that reacts with the exhaust gases in the SCR to reduce NOx.

  • DEF Pump—filters and supplies DEF to the DEF metering unit.

  • SCR Catalyst—the housing containing a treated ceramic flow-through block where the DEF and exhaust gases undergo selective catalytic reduction (SCR).

  • Selective Catalytic Reduction (SCR)—a process used to reduce NOx emissions.

Note:
Parent topic: EPA10 and Newer Exhaust System
Document Number: 0000116771
Manual Publication Date: 2024-05-13
Topic Publication Date: 2024-10-31