Choosing an RECD manufacturer in India is not simply a matter of finding a company that sells emission-control equipment. For diesel generator owners, the manufacturer selected can influence product suitability, installation quality, documentation, maintenance and long-term technical support. CPCB has established a system and 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 available from CPCB was revised on July 24, 2023.

CPCB also publishes a manufacturer list for RECDs applicable to different ranges of in-use diesel genset engines. The list available on its website is dated May 9, 2025 and identifies manufacturers, applicable engine-power ranges, Phase I/Phase II applicability and certification agencies. For generator owners, this provides an important starting point: the manufacturer, product and application should be evaluated together.

What Does an RECD Manufacturer Actually Provide?

An RECD manufacturer may be responsible for much more than supplying a physical exhaust-treatment unit.

Depending on the product and commercial scope, a manufacturer may provide:

• RECD equipment

• Technical specifications

• Product documentation

• Installation guidance

• Controllers or monitoring components

• Exhaust integration support

• Commissioning

• Warranty

• Maintenance assistance

• Spare-parts support

However, the exact scope differs from one supplier to another.

That is why buyers should ask for a detailed quotation instead of assuming every manufacturer offers an identical package.

Why Manufacturer Selection Matters

A diesel generator is an engineered system, and the exhaust arrangement varies between installations.

Two generators with the same kVA rating can have different:

• Engine models

• Engine power

• Exhaust dimensions

• Installation layouts

• Operating conditions

• Existing exhaust arrangements

An RECD that is suitable for one application should not automatically be assumed to be suitable for another.

CPCB's published manufacturer list demonstrates this variation by specifying different engine-power ranges and phase applicability for listed manufacturers.

Start With the Engine

Before contacting an RECD manufacturer, collect the generator's technical information.

Ideally, provide:

Engine manufacturer: ______

Engine model: ______

Engine serial number: ______

Gross mechanical power: ______ kW

DG rating: ______ kVA

Existing exhaust details: ______

Installation location: ______

A clear engine nameplate photograph can also make the initial technical discussion easier.

Understand the Importance of Engine Power

One common mistake is to select an RECD solely according to the generator's kVA rating.

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

Therefore, a proper enquiry should include engine information rather than only saying:

“I need an RECD for a 750 kVA DG set.”

The manufacturer needs enough technical information to establish whether the proposed product is appropriate for the particular application.

Review the Official Manufacturer Information

CPCB's published list is a useful reference when evaluating manufacturers.

The May 9, 2025 list includes manufacturer names, engine-power applicability ranges, Phase I or Phase II applicability and certification agencies.

This means a buyer can ask a manufacturer to clarify:

1. What is the exact RECD model?

2. What engine-power range applies?

3. Which phase is applicable?

4. Which certification agency is identified?

5. What documentation supports the product's stated application?

These questions help move the discussion from general marketing language to product-specific information.

Why Product-Level Verification Matters

Suppose a supplier says:

“Our company supplies CPCB-approved RECDs.”

That statement does not by itself tell you whether the exact product being offered corresponds to your generator.

You should establish:

Manufacturer → Exact Product → Applicable Engine Range → Phase → Supporting Documentation

This is a more useful verification process.

Quality Is More Than Product Appearance

An RECD can look robust and professionally manufactured while still requiring careful technical evaluation.

When assessing quality, consider:

Engineering

Is the product designed for the intended application?

Applicability

Does its documented range correspond to your engine?

Components

Are the major system components clearly identified?

Monitoring

Where applicable, are monitoring and control components documented?

Installation

Does the manufacturer understand how the system should be integrated with the existing exhaust?

Serviceability

Can the manufacturer explain maintenance and replacement requirements?

A quality assessment should therefore include both the product and the manufacturer's technical support.

Examine the Exhaust Installation

Installation is an important part of an RECD project.

Before ordering, evaluate:

• Existing exhaust pipe

• Silencer

• Flanges

• Pipe bends

• Mounting location

• Available clearance

• Access for maintenance

• Exhaust routing

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

That makes it sensible to discuss the existing exhaust configuration with the manufacturer before finalizing an installation.

Ask About Site Inspection

A professional supplier may recommend a site survey before installation.

A survey can help establish:

• Actual exhaust dimensions

• Available mounting space

• Required fabrication

• Cable routing

• Access requirements

• Installation sequence

Not every project will require the same level of site work, but the scope should be established in advance.

Certification and Testing Documentation

Certification is one of the most important areas to review.

CPCB's published list identifies certification agencies for listed manufacturers, including ICAT and ARAI for different entries.

When a manufacturer provides certification information, verify that it relates to the exact product and application being proposed.

Ask for relevant documentation covering:

• Product identification

• Applicable engine-power range

• Phase

• Certification/test information

• Certification agency

• Other technical specifications

Avoid treating a company brochure as the sole evidence of compliance.

Don't Choose a Manufacturer Only Because of Price

Price is obviously important, particularly for projects involving several generators.

But the cheapest quotation may not represent the lowest overall cost.

A quotation could exclude:

• Installation

• Fabrication

• Transportation

• Commissioning

• Monitoring components

• Warranty services

• Future technical support

For this reason, compare the complete project scope.

Warranty Should Be Examined Carefully

Warranty is another area where manufacturers may differ considerably.

Before ordering, ask:

• What is the warranty duration?

• Which components are covered?

• Is labour covered?

• Are site visits covered?

• What are the exclusions?

• How are replacement components supplied?

• How is a claim registered?

A longer warranty period is not automatically better if important components or services are excluded.

Always request written warranty terms.

After-Sales Support Makes a Difference

The relationship with the manufacturer should not end after installation.

Ask about:

Technical Assistance

Can the manufacturer troubleshoot operating issues?

Service Visits

Are technicians available for site support?

Spare Parts

Can replacement components be sourced?

Maintenance

Does the manufacturer provide maintenance recommendations?

Warranty Support

Who handles warranty claims?

For facilities where DG sets are critical backup equipment, these services can be particularly valuable.

Manufacturer vs Supplier: Know the Difference

A company selling an RECD may be:

• Original manufacturer

• Authorized distributor

• Dealer

• System integrator

• Reseller

The buyer should know which one they are dealing with.

Ask:

“Who manufactures the exact RECD model included in this quotation?”

Then establish who is responsible for:

• Certification documentation

• Warranty

• Installation

• Commissioning

• Technical support

• Spare parts

This is especially important when purchasing through a third-party supplier.

What Should a Good Manufacturer Be Able to Explain?

A technically capable manufacturer should be able to discuss your application in practical terms.

For example:

Which engine model do you have?

What is its gross mechanical power?

Which phase applies to the proposed product?

What RECD model is appropriate?

What exhaust modifications are required?

What monitoring components are included?

How will the system be commissioned?

What maintenance does the manufacturer recommend?

A supplier that asks these questions is approaching the project from an application perspective rather than simply selling a standard item.

Choosing an RECD Supplier for DG Sets

When searching for an RECD supplier for DG sets, compare companies using the same technical and commercial criteria.

Product Evaluation

• Exact model

• Engine-power applicability

• Phase

• Technical specifications

Documentation

• Certification/test information

• Datasheet

• Installation documentation

• Warranty terms

Installation

• Site inspection

• Exhaust integration

• Fabrication

• Commissioning

Support

• Service team

• Spare parts

• Technical assistance

• Warranty handling

Commercial

• Equipment price

• Installation cost

• Transportation

• Taxes

• Additional charges

This produces a more balanced comparison than simply collecting the lowest quotation.

Look for Relevant Experience

Manufacturer experience can be useful, particularly when the company has handled installations similar to yours.

Ask whether the company has experience with:

• Similar engine models

• Similar power ranges

• Industrial generators

• Commercial facilities

• Multiple-DG installations

• Complex exhaust layouts

Experience does not replace certification or technical documentation, but it can provide confidence in installation and support capability.

Avoid Unclear Compliance Claims

Be cautious when suppliers use statements such as:

• “100% CPCB approved”

• “Universal RECD”

• “Suitable for every DG”

• “Guaranteed compliance”

• “No maintenance required”

These statements should be explained and supported with appropriate documentation.

CPCB's published list shows that applicability varies by engine-power range and phase, so broad claims should not replace product-specific verification.

Verify Current Regulatory Information

CPCB's website contains a dedicated generator-set section with Type Approval/COP information.

The RECD testing procedure published by CPCB is also an important technical reference.

However, regulatory information can change.

Before finalizing an installation, verify:

• Current CPCB information

• Applicable product documentation

• Relevant State Pollution Control Board/Pollution Control Committee requirements

• Any site-specific directions

Do not depend solely on older blogs, social-media posts or supplier advertisements.

Questions to Ask Before Ordering

Before selecting a manufacturer, ask:

Product

What exact RECD model are you offering?

Application

Which engine-power range does this model cover?

Phase

Which phase is applicable?

Certification

What supporting certification/test documentation can you provide?

Installation

Will you inspect the existing exhaust before installation?

Warranty

Which components and services are covered?

Service

Who provides technical support after commissioning?

Spare Parts

How can replacement components be obtained?

Clear answers to these questions can significantly reduce procurement uncertainty.

Final Checklist for Generator Owners

Before issuing a purchase order, confirm:

• Engine manufacturer recorded

• Engine model recorded

• Gross mechanical power verified

• DG kVA recorded

• Exact RECD model identified

• Manufacturer verified

• Applicable range checked

• Phase checked

• Certification/test documentation reviewed

• Technical datasheet received

• Exhaust arrangement evaluated

• Installation scope defined

• Commissioning included or assigned

• Warranty documented

• Service support confirmed

• Spare-parts availability discussed

• Complete project price compared

Final Thoughts

A leading RECD manufacturer should be evaluated through a combination of technical suitability, documentation, installation capability, service support and commercial transparency. CPCB's published information confirms that RECD applicability differs across manufacturers and engine-power ranges, with Phase I and Phase II applicability identified for listed products. Its published testing procedure provides the framework for emission-compliance testing of applicable RECDs for diesel power-generating-set engines up to 800 kW gross mechanical power. For a business looking for an RECD supplier for DG sets, the strongest purchasing process is therefore not simply “find a manufacturer and ask for the price.” Instead, begin with the generator's exact technical details, identify an appropriate product, verify available documentation, evaluate the installation arrangement and then compare warranty, service and total project cost.