Sistema de exaustão FAW: Um guia crítico para seu 34 Componentes pós-tratamento

Bem-vindo a este guia técnico crítico sobre o Sistema de exaustão FAW para o FAW Jiefang CA4251P66K24T1A3E5 6×4 trator semirreboque diesel. This is not just a muffler; it is a complete, multi-stage emissions after-treatment system, essential for modern diesel performance and environmental compliance.

O Sistema de exaustão FAW is a highly engineered assembly responsible for two primary tasks: noise reduction (muffling) and emissions neutralization. This guide focuses on the ‘Selective Catalytic Reduction (Scr) After-treatment Assembly’ (1208010-90R-C00), qual é o “logic box” that uses urea (DEF) to convert harmful NOx into nitrogen and water.

This in-depth guide is a vital resource for professional technicians, gestores de frota, e especialistas em peças. Vamos desconstruir todo Sistema de exaustão FAW em seu 34 componentes reparáveis, including the main SCR unit, the inlet/outlet piping, the critical heat shields, and all the specialized mounting brackets and hardware.

Componente principal: The SCR After-Treatment Assembly (1208010-90R-C00)

The heart of the modern Sistema de exaustão FAW is the ‘Selective Catalytic Reduction After-treatment Assembly’ (1208010-90R-C00). Este é o grande, montado em chassi “box” that all other components in this list support. It is not a simple muffler; it is an active chemical reactor.

This unit contains a series of catalysts. Primeiro, the hot exhaust gas passes through a **Diesel Oxidation Catalyst (DOC)**, which breaks down carbon monoxide (CO) and unburnt hydrocarbons (HC). Próximo, it passes through a **Diesel Particulate Filter (DPF)**, which is a ceramic “soot trap” that physically captures the black smoke particles.

After the DPF, the urea (DEF) is injected into the gas stream. This mixture then enters the **Selective Catalytic Reduction (Scr)** catalyst. Aqui, the ammonia in the urea reacts with the harmful Nitrogen Oxides (NOx), converting them into harmless nitrogen (N2) e água (H2O). This complex, multi-stage process is the “lógica” do Sistema de exaustão FAW. A failure of this component will trigger a “Check Engine” light and will cause the truck to fail emissions testing.

Inlet Piping and Vibration Damping

O Sistema de exaustão FAW is mounted to the chassis, but the engine vibrates and twists. A rigid pipe connecting the two would snap in minutes. The ‘Telescopic bellows assembly’ (1203040-2000) is the solution. This is a flexible, corrugated steel joint that absorbs the engine’s movement and thermal expansion, protecting the rest of the Sistema de exaustão FAW from stress.

This bellows connects to the ‘Inlet pipe assembly-select catalytic reduction’ (1203815-92C), qual é o principal, pre-bent pipe that feeds the hot gas from the turbocharger into the SCR assembly.

This inlet pipe is heavy and must be supported, which is the job of the ‘Bracket assembly-inlet pipe’ (1203045-92C). Este suporte, along with its ‘Combination bolts’ (CQ1461045) e 'Porcas sextavadas’ (CQ34010), holds the pipe securely to the engine or chassis, preventing it from cracking under its own weight. This entire inlet path is a critical part of the Sistema de exaustão FAW.

The Critical Heat Shield System

The DPF “regeneration” ciclo, which burns off trapped soot, can raise the temperature of the Sistema de exaustão FAW to over 600°C (1100° f). This intense radiant heat is a major fire hazard. This parts list includes a comprehensive heat shield system to protect the truck.

This includes the ‘Heat shield assembly’ (1204045-92W and 1204025-92W), which are large, stamped-metal shields. More specifically, the SCR box is wrapped in its own set of shields:

• ‘Upper heat shield-after-treatment’ (1204038-92C)
• ‘Side heat shield-after-treatment’ (1204046-92C)
• ‘Front heat shield-after-treatment’ (1204028-76C)

These shields create a “barreira térmica” of air, reflecting the heat and protecting the chassis, fuel lines, arnês de fiação, and anything else nearby. A missing heat shield on the Sistema de exaustão FAW is a major safety violation and will lead to melted components. These shields are secured by a ‘Bracket assembly’ (1203055-92C) and specialized ‘Hex flange bolts’ (Q1841455, Q1841450, Q1841475).

Mounting and Support Hardware

The heavy ‘SCR After-treatment Assembly’ (1208010-90R-C00) is held in place by a robust cradle system. This includes the ‘Bracket assembly-after-treatment’ (1203050-92C) and ‘Bracket assembly-after-treatment’ (1203055-92C).

These brackets are secured to the chassis, and the SCR box is then held by the ‘Clamping band assembly-after-treatment’ (1203090-73C). These bands wrap around the unit and are tensioned with bolts. To prevent metal-on-metal contact, a ‘Gasket plate assembly’ (1203025A263) is used as a vibration-damping insulator.

The rest of the Sistema de exaustão FAW, such as the tailpipe, is hung using the ‘Clamp-muffler hanger’ (1203041-274). The entire assembly is fastened with a large array of ‘Hex flange lock nuts’ (CQ32610, Q932614), 'Hex nozes’ (CQ34010, CQ34008, CQ34012), 'Parafusos de cabeça sextavada’ (CQ1501030, CQ1501025), e 'Juntas de mola’ (Q40310, Q40308). This hardware is all high-temperature and vibration-resistant, essential for the reliability of the Sistema de exaustão FAW.

FAW Exhaust System Parts List

A tabela a seguir fornece o completo, detalhamento de todos 34 components identified in the ‘Exhaust System’ diagrama para o trator FAW CA4251P66K24T1A3E5. Esse Sistema de exaustão FAW is a complex after-treatment assembly.

Especificações Técnicas e Contexto de Montagem

As especificações para o Sistema de exaustão FAW são definidos por sua função como um completo, chassis-mounted emissions after-treatment system. O inteiro Sistema de exaustão FAW is critical for emissions compliance and noise reduction.