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Tier 4i Engine Diagrams

Tier 4i Engine Technology

D4H, D6H, D8H Tier 4i

The Volvo D4H, D6H and D8H use Diesel Particle Diffuser (DPD) Technology to achieve Tier 4i emissions regulations. The “DPD” is made up of both parts below.

  • Part 1 - Diesel Oxidation Catalyst (DOC) - A DOC is a device that uses a chemical process to break down pollutants in the exhaust stream into less harmful components. More specifically, it is a physical device with a porous ceramic honeycomb-like structure that is coated with a material that helps promote a chemical reaction to reduce pollution.
  • Part 2 - Diesel Particulate Filter (DPF) - captures the “soot” or particulate matter in the exhaust system before it exits the exhaust system. The “soot” is what is left from chemical breakdown.
  • D4H, D6H, D8H uses both PASSIVE and ACTIVE regeneration to achieve emission regulations.
    • PASSIVE Regeneration = Fuel Dosing Approach – Simply dosing the DOC with fuel to increase exhaust temperatures to ~1020 F (~550 C). No burning takes place.
    • ACTIVE Regeneration = Fuel Burning Approach – A burner is used to ignite the fuel to increase exhaust temperatures to ~1020 F (~550 C).
    • The engine software will decide which approach is needed.
  • These engines also incorporate crankcase ventilation and Cooled Exhaust Gas Recirculation. These parts combined help achieve Tier 4i emissions regulations.
  • Servicing occurs at no less than 4500 hours
  • The DOC and DPF are separate items – ONLY the DPF will be serviced and can be exchanged

D11H, D13H, D16H Tier 4i

The Volvo D11H, D13H and D16H use only Diesel Particle Filter Technology to achieve Tier 4i emissions regulations. It does not incorporate a Diesel Oxidation Catalyst (DOC).

  • D11H, D13H, D16H uses ACTIVE regeneration to achieve emission regulations.
    ACTIVE Regeneration = Fuel Burning Approach – A burner is used to ignite the fuel to increase exhaust temperatures to ~1160 F (625 C).  
  • These engines also incorporate a variable turbocharger, crankcase ventilation component and Cooled Exhaust Gas Recirculation, After-treatment Support Unit & control module.  Air pump provides air for burner during regeneration cycle and air compressor delivers high pressure air for fuel injection.
  • Servicing occurs at no less than 4500 hours