Choosing an RECD device as per CPCB norms is a technical procurement decision, not simply a matter of comparing two quotations. Generator owners need to verify the DG engine, gross mechanical power, exact RECD model, supporting documents, installation requirements, warranty and long-term service before placing an order. CPCB has published a formal procedure for emission-compliance testing of Retrofit Emission Control Devices (RECDs) for diesel power-generating-set engines up to 800 kW gross mechanical power. The procedure establishes a framework covering Type Approval, testing and Conformity of Production for applicable RECDs.
Begin With the Generator
Before contacting an RECD manufacturer, prepare the technical details of the DG set. The engine manufacturer, exact engine model, engine serial number, gross mechanical power, DG kVA rating, rated speed and existing exhaust arrangement provide the foundation for product selection.
This is important because a generator's commercial kVA rating does not provide enough information by itself. CPCB's published RECD documentation distinguishes applications according to engine and gross mechanical power. During Type Approval, the RECD and engine combination is tested for mechanical gross power, while the corresponding kVA is checked against the engine and DG-set data plates. A supplier that asks for detailed engine information before recommending a device is generally taking a more application-specific approach.
Confirm the Exact RECD Model
One of the simplest but most important buying checks is product identification.
A purchase order should not merely say:
“RECD system – 1 unit.”
The quotation should identify the manufacturer, exact RECD model or type, applicable engine/power range and quantity. The same model should then appear consistently in the datasheet and supporting documentation.
CPCB's procedure includes conformance-labelling requirements covering information such as the manufacturer or Type Approval certificate holder, manufacturing plant, RECD model, class, identifying part number, unique identification number, manufacturing date and Type Approval certificate number. This traceability becomes useful later for warranty claims, servicing and technical verification.
Verify the Engine Application
A genuine RECD can still be the wrong product for a particular DG.
Ask the manufacturer to confirm the applicable engine range and gross mechanical power for the proposed model. Also check whether the relevant product documentation identifies the applicable Phase and engine application. CPCB's published manufacturer information lists RECD manufacturers according to specific engine-power ranges and Phase I or Phase II applications. For a facility operating several generators, this check should be performed for each significantly different DG rather than assuming that one product can be installed everywhere.
Request the Certification and Testing Documents
The next step is to obtain the relevant product documentation. CPCB's published RECD procedure requires manufacturers, importers and retrofitters supplying applicable RECDs to obtain Type Approval and comply with Conformity of Production requirements. The procedure also describes approved technical agencies for the relevant testing framework.
When buying, ask for the documentation that identifies the exact product being offered and the applicable engine/application. Do not rely solely on a screenshot, brochure, WhatsApp message or statement such as “CPCB certified.” A proper procurement file should contain documents that can be matched to the actual RECD model.
Understand What Is Being Tested
A buyer should also understand that RECD evaluation is not simply a visual inspection of the product. CPCB's testing procedure covers parameters and testing considerations related to particulate matter, gaseous emissions, smoke, specific fuel consumption, regeneration characteristics and exhaust back pressure, depending on the applicable test framework.
This is important when reading manufacturer brochures. If a supplier advertises a percentage emission reduction, ask which model and engine were tested, what test conditions applied and whether the result is relevant to your proposed installation. A test result should not automatically be presented as a guaranteed real-world performance figure for every generator.
Check the Exhaust and Installation Requirements
Buying the device is only part of the retrofit. The existing exhaust system should be considered before finalizing the installation. Pipe diameter, flange arrangement, silencer position, routing, supports, mounting space and maintenance access can all affect the work required.
CPCB's procedure specifically includes exhaust back pressure in the technical testing framework. A site survey is therefore useful for installations where fabrication or exhaust modifications may be necessary. The quotation should clearly state whether site inspection, fabrication, installation, transportation and commissioning are included or billed separately.
Look at the Complete Project Cost
The equipment price is not necessarily the final project cost. An accurate comparison should consider the RECD itself together with fabrication, installation, transportation, commissioning and applicable service charges. Warranty and future maintenance should also be reviewed because a low initial quotation may not represent the lowest lifecycle cost.
For example, one supplier may quote a lower device price but charge separately for fabrication and commissioning, while another may include these activities in a higher turnkey quotation. The right comparison is therefore complete project scope versus complete project scope.
Evaluate the Manufacturer's Support
A good RECD purchase should include a clear support arrangement. Before ordering, establish who will perform the installation, who provides commissioning, who handles warranty claims and where spare parts can be obtained.
Ask about the manufacturer's service network, preventive maintenance options and technical response arrangements. For an industrial facility, serviceability can become as important as the initial equipment specification, especially when the DG is used for critical backup power.
Where the DG generator emission control device Fits Into the Decision
A DG generator emission control device should be evaluated as part of a complete emissions-control solution rather than as an isolated exhaust component. The buyer should consider the product's engine application, documentation, exhaust compatibility, installation method, maintenance requirements and long-term support together.
This approach also helps avoid a common procurement error: selecting a device because it appears suitable from its nameplate or kVA category without confirming its application with the manufacturer.
Review Warranty Before Paying
Warranty terms should be documented before the purchase order is finalized. Check the warranty duration, start date, covered components, installation conditions, labour coverage, site visits, exclusions and claim process.
Also ask whether the manufacturer requires installation by its own team or an approved service partner to maintain warranty validity. A written warranty is much more useful than a quotation that simply says “standard warranty.”
Check Maintenance Requirements in Advance
A retrofit system should be evaluated over its complete operating life. Depending on the product, maintenance may involve inspection of sensors, controllers, regeneration-related functions, filters or other components.
The manufacturer should provide a model-specific maintenance schedule. Do not apply the maintenance interval of one RECD model to another simply because both are marketed for diesel generators. Keep service records containing the installation date, operating hours, maintenance performed, parts replaced and technician details.
Verify the Supplier's Manufacturing Status
The word “manufacturer” should also be verified. Ask where the proposed RECD is manufactured and whether the company is the original manufacturer or a supplier of another company's product.
For example, Aceget states that its RECD products are designed and manufactured at its Noida facility and publishes model-specific product and certification information on its website. The same verification approach should be used for any manufacturer under consideration.
Keep a Product File for Every DG
Once the purchase is completed, maintain a dedicated record for the individual generator. The file should contain the DG engine information, RECD manufacturer, exact model, serial/identification number, technical datasheet, relevant Type Approval information, installation report, commissioning record, warranty and service history.
This makes future maintenance and technical verification much easier. It also prevents confusion when several DG sets operate at the same facility.
CPCB Compliance Must Be Verified Separately
The most important caution in an RECD purchase is that product documentation and overall site compliance are not necessarily the same thing. CPCB's published RECD procedure establishes a framework for testing and approval of applicable retrofit devices. However, whether a particular DG installation satisfies all applicable requirements can depend on the engine, installation, location and current regulatory provisions.
CPCB also provides official Generator Sets resources, including Type Approval/COP-related information.
Final Buying Checks
Before issuing the purchase order, make sure the DG engine details have been verified, the gross mechanical power is known, the exact RECD model is identified, the application range is confirmed and the relevant technical documentation has been received.
The installation scope should also be written down, including fabrication and commissioning. Finally, confirm the warranty, maintenance requirements, spare-parts availability and service support. A good procurement file should allow someone reviewing the project later to answer five simple questions:
Which DG was involved?
Which RECD was purchased?
Why was that model selected?
What documentation supports it?
Who is responsible for installation and future service?
Frequently Asked Questions
What should I verify before buying an RECD?
Start with the exact engine model and gross mechanical power. Then verify the RECD model, documented application, relevant Type Approval information and installation requirements.
Is a kVA rating enough to select an RECD?
No. Engine information and gross mechanical power should also be checked because RECD applicability is tied to specific engine applications and power ranges.
What documents should an RECD manufacturer provide?
Request the exact model information, technical datasheet, relevant Type Approval or test documentation, applicable engine range, installation requirements and warranty terms.
Does an “CPCB approved” label guarantee site compliance?
No. Product approval/testing and complete site compliance are separate matters. Current requirements applicable to the particular DG and location should be verified directly through official sources.
Should installation be included in the purchase quotation?
The installation scope should at least be clearly defined. Ask whether site survey, fabrication, installation, transportation and commissioning are included or separately charged.
Conclusion
Buying an RECD device as per CPCB norms should be approached as a technical and documentation-driven procurement exercise. The strongest purchase decision begins with the generator itself and moves through product selection, application verification, certification, installation, warranty and long-term support. A manufacturer should be able to identify the exact product being supplied and explain why it is appropriate for the intended engine. The buyer should then verify the relevant documentation instead of relying on broad marketing language. The best RECD purchase is not simply the device with the lowest price. It is the product that is appropriately matched to the generator, supported by traceable documentation, correctly installed and backed by dependable service.