Construction machinery – excavators, bulldozers, wheel loaders, backhoes, motor graders, and compact track loaders – operates in demanding environments: extreme vibration, dust, moisture, and tight urban job sites. Regulations: EU Stage V, EPA Tier 4 Final, China Stage IV. Required reductions: PM 90–99%, NOx 80–95%. Our DOC, DPF, and SCR aftertreatment systems are rugged, space-efficient, and serviceable.
Equipment operates under continuous vibration, extreme dust, tight packaging, and variable duty cycles. Unlike agricultural machinery, construction machines work in confined spaces (urban sites, tunnels, indoor demolition), requiring safe exhaust heat and emissions management.
Power Range | Typical Machinery | Aftertreatment Configuration |
<56 kW (75 hp) | Compact equipment, skid steers, mini excavators | DOC or DOC+DPF |
56–130 kW (75–174 hp) | Midi excavators, compact loaders, backhoes | DOC → DPF → SCR (ASC optional) |
130–560 kW (174–750 hp) | Large excavators, bulldozers, wheel loaders | DOC → DPF → SCR → ASC → Tailpipe |
Converts CO and HC, generates NO₂ for DPF regeneration. Must tolerate extreme vibration (10–20g, 50–200 Hz). Compact packaging and oversized volume (20–30% larger) for extended service intervals.
Traps soot and ash. It uses a wall-flow cordierite or SiC substrate with more than 99% filtration efficiency. Passive regeneration happens during normal driving using NO₂. Active regeneration uses fuel post-injection and DOC exotherm when soot load exceeds the threshold, typically 4–6 g/L. Service life is 300,000+ km with proper ash cleaning.
The primary NOx removal system. It uses Cu-zeolite at 175–500°C or Fe-zeolite at 250–550°C on a cordierite honeycomb. DEF, also known as AdBlue, contains 32.5% urea and is injected upstream. It decomposes into NH₃, which reduces NOx into N₂ and H₂O. Conversion efficiency is 90–99%. Closed-loop control is managed with upstream and downstream NOx sensors.
Reduces NH₃ slip to <10 ppm for enclosed cabs and underground construction.
Pollutant | Engine Out | After Aftertreatment (Stage V / Tier 4) | Efficiency |
NOx | 300–1,000+ ppm | <0.4 g/kWh (56–560 kW) | 85–95% |
PM | 0.1–0.8 g/kWh | <0.015 g/kWh | >98% |
CO | 100–500 ppm | <10 ppm | >95% |
HC | 50–200 ppm | <10 ppm | >95% |
Machinery | Power Range | Aftertreatment | Key Challenges |
Mini excavator | <56 kW | DOC + DPF | Tight packaging, indoor regen inhibit |
Midi excavator | 56–130 kW | DOC + DPF + SCR | Vibration, urban job sites |
Large excavator | 130–560 kW | DOC + DPF + SCR + ASC | Long hours, high load, operator comfort |
Skid steer / compact track loader | <75 kW | DOC + DPF | Low load, frequent starts, dust |
Wheel loader | 100–500 kW | DOC + DPF + SCR + ASC | Extreme dust, reversing fans |
Bulldozer | 200–560 kW | DOC + DPF + SCR + ASC | High load, remote operation |
Backhoe loader | 50–100 kW | DOC + DPF + SCR | Mixed duty cycle, public roads |
Motor grader | 100–300 kW | DOC + DPF + SCR | Variable load, precision grading |
Compactor / roller | 50–150 kW | DOC + DPF | Extreme vibration, low-speed operation |
Demolition excavator | 200–500 kW | DOC + DPF + SCR + ASC | Extreme dust, fire risk |
Rubber-isolated mounts, braided stainless DEF lines, sealed IP67/IP69K connections, thick-wall canning (3–4 mm stainless).
Active regen controlled by soot load, regen inhibit for hazardous areas, parked regeneration on job site.
Vertical or side-mounted configurations, SCRoF for compact space, heat shields protect hydraulic lines and fuel tanks.
Regeneration inhibit, high-temperature warning decals, insulated/double-wall cans (<200°C surface).
Electric pre-heater and eSCR maintain catalyst temperature during low-load or indoor operation. Battery-powered DEF heater and line heater. MSHA/ATEX certified.
Real-time monitoring of soot load, regeneration status, DEF level, fault codes. Predictive alerts for maintenance.
Thousands of systems worldwide. Validated to Stage V, Tier 4 Final, China Stage IV.
Vibration-tested, dust/water ingress tested, thermal cycling (-40°C to +800°C, 1,000 cycles).
eSCR for zero-emission operation, low surface temperature packages (<180°C).
Dealer network and field service engineers available during critical project windows.
From 20 kW aerial lifts to 300 kW air compressors, our industrial diesel aftertreatment solutions deliver worker-safe emissions, indoor-compatible regeneration, and regulatory compliance without productivity compromise. Partner with us to engineer your path to cleaner factory operations.