Retrofitting SCR: Why Experience Matters

Thursday 30th July 2026

Retrofitting Selective Catalytic Reduction (SCR) exhaust aftertreatment onto existing generator installations is rarely straightforward. Every project presents its own engineering challenges, from limited installation space to engine operating conditions that can affect system performance.

The challenges of SCR retrofits

Limited installation space

Generator rooms and plant areas are often already congested, leaving very little room to accommodate additional exhaust treatment equipment.

Engine backpressure limits

Adding reactors, silencers and pipework can increase exhaust backpressure beyond the engine manufacturer's limits, potentially affecting engine performance and reliability.

Temperature and dosing control

Maintaining catalyst operating temperatures during low-load operation and accurately controlling AdBlue® dosing are essential to achieving high NOx reduction while preventing deposit formation.

Why customers choose Agriemach

Successful SCR retrofits require more than quality components - they demand careful mechanical and thermal engineering.

• Bespoke system design – Our NOxMASTER™ SCR systems are engineered to suit each application, taking account of exhaust mass flow, operating temperatures and engine-out emissions.

• Compact integrated solutions – By combining silencing, the mixing duct and SCR reactor into a single engineered assembly, we minimise installation footprint while remaining within engine backpressure limits.

• Complete project delivery – Since 1976, we've supported customers across the UK and Ireland with design, installation, commissioning and ongoing service, helping keep projects on schedule and performing reliably.

Whether you're upgrading an existing generator to meet tighter emissions requirements or planning a new compliance strategy, our emissions team can help. We've successfully delivered SCR retrofit solutions for a wide range of challenging installations and would be happy to discuss your application.

Engineered solutions – it's what we do.