Choosing an RECD manufacturer in India requires more than comparing product prices or searching for the company with the most attractive specifications. The right manufacturer should be evaluated on product applicability, technical documentation, certification information, installation capability, service support and long-term reliability.

Retrofit Emission Control Devices (RECDs) are designed for applicable in-use diesel generator engines to help address particulate emissions. CPCB has published a system and procedure for emission-compliance testing of RECDs for diesel power-generating-set engines up to 800 kW gross mechanical power. The procedure was revised on July 24, 2023. For businesses, institutions and industrial facilities planning an RECD project in 2026, understanding how to evaluate manufacturers can make the purchasing process more transparent and technically sound.

What Is an RECD Manufacturer?

An RECD manufacturer develops and produces retrofit emission-control equipment intended for installation on applicable in-use diesel generator engines.

The manufacturer's responsibilities can extend beyond manufacturing the physical equipment. Depending on the supplier and project, support may include:

• Product engineering

• Technical evaluation

• Product testing

• Certification-related documentation

• Site assessment

• Installation

• Commissioning

• Maintenance guidance

• Warranty support

• Spare-parts assistance

This is why the term “manufacturer” should not be treated as interchangeable with “trader” or “reseller.”

For an emission-control project, the technical identity of the product matters just as much as the company selling it.

Why Manufacturer Selection Matters

A diesel generator is a significant mechanical system, and its exhaust arrangement differs from one installation to another.

Two generators may have similar kVA ratings but different:

• Engine manufacturers

• Engine models

• Gross mechanical power

• Exhaust configurations

• Installation conditions

• Applicable phases

CPCB's published list of certified RECD manufacturers demonstrates this variation. The list provides different applicability ranges for in-use diesel genset engines and identifies Phase I or Phase II applicability for listed manufacturers.

Therefore, choosing an RECD should start with the generator's technical information rather than simply selecting a familiar brand.

What to Check Before Shortlisting Manufacturers

Before contacting manufacturers, collect the basic details of your DG set.

Generator Information

Record:

• DG-set manufacturer

• Engine manufacturer

• Engine model

• Engine serial number

• DG capacity in kVA

• Engine gross mechanical power in kW

• Manufacturing details, where available

• Existing exhaust-pipe details

• Installation location

A clear photograph of the engine and DG-set nameplates can also be useful when requesting technical confirmation.

kVA Alone Is Not Enough

One of the most common procurement shortcuts is to identify a generator only by its kVA rating.

For RECD evaluation, engine information is important.

CPCB's published RECD manufacturer list specifies applicability using ranges of in-use diesel genset engine power in kW.

For example, rather than telling a manufacturer:

“We need an RECD for a 500 kVA DG.”

provide:

Engine model + gross mechanical power + DG capacity + phase/application information.

This gives the manufacturer enough information to begin a more meaningful technical assessment.

Understanding CPCB-Related Certification Information

CPCB's published list identifies manufacturers certified for RECD applications and provides information about applicable engine-power ranges, Phase I/Phase II applicability and certification agencies. The currently published list is dated May 9, 2025.

The list includes certification agencies such as ICAT and ARAI for different listed applications.

For a buyer, this means that “CPCB certified” should not be treated as a complete product description.

Instead, verify:

Manufacturer → RECD/product → Engine-power range → Phase → Certification information

This approach is more useful when reviewing competing suppliers.

Don't Assume Every Product From a Manufacturer Is Identical

A manufacturer may have more than one RECD configuration or application range.

One product may cover a particular engine-power range, while another may cover a different range.

CPCB's published list itself demonstrates that manufacturers can have multiple applicability ranges and phase classifications.

Therefore, ask for the exact model and application information instead of relying only on the manufacturer's name.

Technical Quality Should Be a Priority

Price is naturally important, but technical quality should come first.

When comparing manufacturers, examine:

Product Construction

Ask about the equipment's construction, components and design.

Engine Compatibility

Confirm that the proposed system is intended for the relevant engine and power range.

Installation Requirements

Understand how the equipment is integrated into the existing exhaust arrangement.

Monitoring Components

If the system includes sensors or controllers, ask what they monitor and how the system communicates operating conditions.

Maintenance

Request manufacturer-specific maintenance recommendations.

A technically suitable product should be supported by appropriate documentation.

Exhaust Configuration Matters

An RECD installation is not independent of the generator's exhaust system.

Before installation, the manufacturer or technical team may need information about:

• Exhaust diameter

• Pipe routing

• Flanges

• Silencer position

• Available space

• Mounting arrangements

• Exhaust bends

• Maintenance access

CPCB's RECD testing procedure includes exhaust back pressure among the technical parameters considered in the compliance-testing framework.

This is one reason an experienced manufacturer should evaluate the actual installation instead of recommending equipment purely from the DG-set capacity.

Look for Strong Technical Documentation

A reliable manufacturer should be able to explain its product clearly.

Before purchasing, request relevant documents such as:

• Product datasheet

• Technical specifications

• Application range

• Phase applicability

• Certification/test information

• Installation instructions

• Operating instructions

• Maintenance information

• Warranty conditions

The exact documentation available will depend on the product.

Compare the model number shown in the documentation with the model quoted in the commercial proposal.

If they do not match, ask for clarification before placing the order.

Installation Support Is an Important Differentiator

Manufacturing the equipment is only one stage of an RECD project.

Installation can involve:

• Site inspection

• Exhaust measurement

• Mounting

• Pipe modification

• Fabrication

• Sensor installation

• Controller installation

• Wiring

• Commissioning

Ask whether these services are performed by the manufacturer, an authorized service team or another contractor.

For complicated installations, manufacturer-led technical support can make project coordination easier.

Evaluate After-Sales Service

A good supplier relationship should continue after installation.

Ask about:

• Warranty support

• Service visits

• Preventive maintenance

• Spare parts

• Technical troubleshooting

• Remote assistance

• Complaint registration

• Escalation process

For facilities that depend heavily on standby generators, service availability can be particularly important.

An inexpensive product with weak support may create more operational difficulties later.

Warranty Should Be Clearly Defined

Don't select a manufacturer simply because it advertises a long warranty.

Read the conditions.

Check:

• Warranty duration

• Covered components

• Exclusions

• Labour coverage

• Travel conditions

• Replacement process

• Warranty claim procedure

A written warranty is preferable to a general verbal assurance.

Manufacturer vs Supplier: What Is the Difference?

A buyer may encounter three types of companies:

Manufacturer

Designs and produces the RECD equipment.

Authorized Supplier/Distributor

Sells equipment produced by another manufacturer and may provide installation or service.

General Trader

May source equipment from different manufacturers and resell it.

None of these categories should automatically be considered good or bad.

The important point is transparency.

Ask:

“Are you the manufacturer of this exact RECD model?”

If the answer is no, ask:

“Who is the actual manufacturer, and what technical and warranty support do you provide?”

This helps establish accountability.

How to Identify an Appropriate RECD Supplier for DG Sets

When searching for an RECD supplier for DG sets, don't search only by city or price.

Use a supplier-selection process based on:

1. DG-set identification

2. Engine-power verification

3. Product applicability

4. Phase verification

5. Documentation

6. Installation capability

7. Warranty

8. After-sales service

A supplier should be able to connect the proposed product to your actual generator specifications.

Ask for a Site Assessment

A site survey can be particularly useful for:

• Large generators

• Multiple DG installations

• Difficult exhaust layouts

• Restricted installation spaces

• Projects requiring fabrication

The survey should establish whether the proposed product can be physically integrated into the existing installation according to the manufacturer's technical requirements.

Don't Ignore Documentation During Bulk Procurement

For multiple installations, retain:

• Purchase orders

• Invoices

• Product datasheets

• Certification/test documentation

• Installation reports

• Commissioning reports

• Serial numbers

• Warranty certificates

• Maintenance records

A structured documentation system can make future service and technical verification easier.

Red Flags During Manufacturer Selection

Be cautious if a supplier:

• Refuses to identify the exact model

• Provides no technical documentation

• Gives only verbal certification claims

• Cannot explain engine applicability

• Avoids questions about phase

• Cannot define warranty conditions

• Offers an unexplained price far below competing quotations

• Cannot explain installation requirements

• Uses outdated regulatory information without verification

These signs do not automatically prove that a product is unsuitable, but they justify additional verification.

Don't Buy Based on “Lowest Price”

An RECD quotation should be evaluated as a complete package.

Consider:

Equipment + Installation + Fabrication + Commissioning + Warranty + Service + Spare Parts

A low equipment price may not remain low after installation and support costs are added.

Ask every shortlisted manufacturer to provide a comparable scope.

What Makes a Strong RECD Manufacturer?

A strong manufacturer should ideally demonstrate:

Technical Understanding

Ability to evaluate the actual DG-set engine and installation.

Product Documentation

Clear specifications and applicable technical information.

Certification Transparency

Ability to provide relevant certification/test information without vague claims.

Installation Capability

Ability to support proper physical integration.

Service Infrastructure

A clear process for troubleshooting and maintenance.

Warranty Clarity

Written terms that define coverage and exclusions.

Regulatory Awareness

Willingness to direct customers toward current official requirements rather than relying on outdated claims.

Verify Current CPCB Information

CPCB maintains dedicated generator-set resources, including type-approval/COP information and related regulatory material.

Because regulatory information can change, buyers should verify the current position before finalizing an RECD project.

Do not rely exclusively on:

• Old blog posts

• Search snippets

• Social-media claims

• Unverified advertisements

• Informal sales messages

• Old certificates without checking their applicability

Where applicable, also review requirements or directions issued by the relevant State Pollution Control Board or Pollution Control Committee.

A Practical Manufacturer Selection Checklist

Before placing your order, confirm:

DG Set

• Engine manufacturer identified

• Engine model recorded

• Engine serial number recorded

• Gross mechanical power verified

• DG capacity recorded

• Nameplate photographs collected

RECD

• Exact manufacturer identified

• Exact product/model identified

• Engine-power range checked

• Phase applicability checked

• Supporting certification/test information reviewed

Installation

• Exhaust dimensions checked

• Site survey completed where necessary

• Mounting arrangement reviewed

• Fabrication requirements identified

• Commissioning scope confirmed

Commercial

• Equipment price confirmed

• Installation cost confirmed

• Fabrication charges confirmed

• Transportation confirmed

• Taxes and additional charges clarified

Support

• Warranty received in writing

• Service process explained

• Spare-parts availability discussed

• Maintenance instructions received

• Technical contact provided

Final Thoughts

Selecting an RECD manufacturer should be approached as a technical procurement decision, especially when the equipment is being purchased for an existing diesel generator and regulatory compliance is part of the objective. CPCB's published information shows that RECD applicability is not simply a manufacturer-level question. The published list connects manufacturers with specific in-use diesel genset engine-power ranges, Phase I/Phase II applicability and certification agencies. For buyers, the practical approach is straightforward: identify the generator accurately, confirm the engine's gross mechanical power, determine the applicable phase, verify the exact RECD model, review supporting documentation and evaluate installation and after-sales capabilities. For organizations researching an RECD supplier for DG sets, the strongest candidates are those that can clearly explain product applicability, provide appropriate documentation, define installation responsibilities and offer transparent warranty and service arrangements.