In short. Selection starts with the engine and its real duty, not with the device. Exhaust temperature, back-pressure margin, fuel quality, space and approval path decide compatibility. A clear go or no-go checklist avoids costly retrofits that cannot work.
Data to collect
| Item | Why |
|---|---|
| Engine make, model, year, kW | Compatibility and approvals |
| Exhaust flow and temperature at load | Device sizing and regeneration |
| Allowed back-pressure | Engine protection |
| Load profile and run hours | Regeneration and ash |
| Fuel and lube oil quality | Catalyst life |
| Space and exhaust route | Fit and safety |
Compatibility checks
- Back-pressure with the device is within the engine limit.
- Exhaust temperature reaches regeneration range at realistic load.
- Mechanical fit: weight, supports, thermal expansion.
- Controller and sensors can be integrated.
- Approval route is clear.
Go or no-go
- Go: stable duty, good temperature, margin on back-pressure.
- Caution: low-load standby duty; consider active regeneration.
- No-go: poor engine condition, excessive oil consumption, or no approval path.
Compare with other routes: RECD vs dual fuel vs replacement.
Illustrative example
An engine with high oil consumption would foul a catalyst quickly. The assessment recommends overhaul before retrofit, or replacement, instead of fitting a device that will not last.
Measurements to take before any quotation
| Measurement | How |
|---|---|
| Exhaust temperature at 50, 75 and 100 percent load | Thermocouple after the turbocharger or at the exhaust outlet |
| Back-pressure at rated load | Gauge at the engine outlet |
| Smoke level | Opacity or visual check against a known scale |
| Oil consumption | Record top-ups against hours |
| Fuel quality | Sulphur and contamination checks |
These can be taken during a load bank test. See load bank testing.
How exhaust temperature decides the design
Catalysts and filters work only above certain temperatures. An engine that rarely exceeds those temperatures at its real loads needs an active strategy such as periodic temperature raising, a different device, or a duty change. Selecting from nameplate rating alone ignores this and is a common cause of failure.
Sizing the device
Catalyst and filter volume relate to exhaust flow. Undersized units give high back-pressure and short filter life; oversized units cost more and may run cool. Makers size from engine displacement, rated flow and temperature, which is why accurate engine data matters.
Go or no-go scoring (illustrative)
- Engine sound, low oil consumption: pass.
- Exhaust temperature adequate or active strategy feasible: pass.
- Back-pressure margin at least a comfortable fraction of the limit: pass.
- Space and structural support available: pass.
- Approval route known: pass.
- Remaining engine life justifies the investment: pass.
A fail on engine condition or approval usually ends the retrofit route. A fail on temperature or space may be solvable at extra cost.
Documentation for the file
Keep the baseline measurements. They prove the starting condition, and they let you show improvement afterwards. They also help settle any dispute with a supplier about performance.
The master engineering question
If we fit this device, will it work for years or fail in months, and what evidence says so?
What to send us
Send engine data and logs. Send your application details. See the overview of RECD.
Questions engineers ask
Can I measure back-pressure now?
Yes, with a gauge at the exhaust manifold or outlet.
Is oil consumption a problem?
Yes, it contaminates filters and catalysts.
What if the set runs lightly loaded?
Plan regeneration or choose another route.
Who decides approval?
The relevant regulator for your location.
General guidance only. Use engine maker data.