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How to Review an Ex Equipment Datasheet Before Procurement: A Practical Engineering Checklist

Review Ex equipment datasheets before procurement with a practical checklist covering hazardous areas, certification, EPL, temperature, and ratings.
Ex equipment datasheet review and procurement checklist at a petrochemical facility
Ex equipment datasheet review covering hazardous area classification, EPL, protection concept, certification, temperature class, and installation requirements.

Selecting explosion-protected equipment is not simply a matter of finding a product with an Ex marking. Before an item is approved for procurement, its datasheet, hazardous area requirements, certification, environmental ratings, and installation requirements must be checked against the project specification.

This review is particularly important during FEED, tendering, and technical bid evaluation, when a vendor's offer may appear compliant but still contain significant technical deviations.

This guide provides a practical checklist for engineers, EPC procurement teams, technical buyers, and project personnel reviewing Ex equipment before purchase.

1. Start With the Project Requirements

Review the project requirements before evaluating the manufacturer's proposed product. Establish the following information:

  • Hazardous area classification and installation location
  • Required Equipment Protection Level (EPL)
  • Applicable protection concept
  • Gas or dust group
  • Required temperature class or maximum surface temperature
  • Minimum and maximum ambient temperature
  • Electrical and mechanical requirements
  • Environmental conditions and ingress protection
  • Certification and documentation requirements

Best practice: Define the acceptance criteria first, then compare the vendor's offer against each requirement.

2. Verify the Hazardous Area Classification

Confirm where the equipment will be installed and which hazardous atmosphere may be present. Gas or vapour areas may be classified as Zone 0, Zone 1, or Zone 2. Combustible dust areas use Zone 20, Zone 21, or Zone 22.

The equipment selection must be consistent with the project's hazardous area classification and applicable selection requirements.

Project parameter What to verify
Hazardous area Zone classification and installation location
Atmosphere Gas, vapour, mist, or combustible dust
Equipment group Required gas or dust group
EPL Required equipment protection level
Temperature Required temperature class or maximum surface temperature
Ambient conditions Minimum and maximum operating temperatures

Checking only the zone designation is not sufficient. The other parameters must also be verified against the project requirements.

3. Check the Protection Concept and EPL

Confirm the equipment's protection concept and EPL from its complete Ex marking and supporting documentation.

Common protection concepts include:

  • Ex d: Flameproof enclosure
  • Ex e: Increased safety
  • Ex i: Intrinsic safety
  • Ex p: Pressurization
  • Ex t: Protection by enclosure for explosive dust atmospheres

For gas atmospheres, EPL designations include Ga, Gb, and Gc. Dust equipment uses Da, Db, and Dc.

Best practice: Confirm that the protection concept and EPL satisfy the applicable project requirements. Do not rely on a generic vendor statement such as "suitable for hazardous areas."

4. Read the Complete Ex Marking

Consider this illustrative marking:

Ex db IIC T4 Gb

Each element communicates information that must be evaluated against the project requirements.

Marking Procurement review
Ex db Confirm the protection concept is appropriate for the application.
IIC Verify that the gas group meets the project requirement.
T4 Check that the temperature classification is suitable.
Gb Confirm that the EPL meets the required level.

This example is illustrative only. The complete marking, including any additional suffixes, ambient temperature information, and certificate conditions, must be checked for the actual product.

5. Verify the Temperature Class and Ambient Range

Temperature classification and ambient temperature are related but separate checks.

For gas equipment, temperature classes include T1 through T6. The selected equipment must satisfy the temperature requirement established for the hazardous substance and application.

Separately, verify that the certified ambient temperature range covers the expected installation conditions.

  • Compare the required temperature class with the equipment marking and certification.
  • Check minimum and maximum ambient temperatures.
  • Confirm whether the selected model or configuration affects the ratings.
  • Use the certified operating range, not just a general marketing specification.

Best practice: Record temperature class and ambient range as separate items in the technical bid evaluation.

6. Check Electrical Ratings

Ex certification does not automatically mean that the equipment's electrical characteristics meet the project specification.

Depending on the equipment, verify:

  • Rated voltage and frequency
  • Rated current and power consumption
  • Power factor, where relevant
  • Starting or inrush current, where relevant
  • Short-circuit requirements, where applicable
  • Terminal configuration and earthing requirements
  • Number and type of cable entries

For lighting equipment, also review parameters such as lumen output, colour temperature, CRI, beam distribution, mounting arrangement, and emergency-lighting requirements where specified.

Best practice: Evaluate hazardous area suitability and normal electrical performance as related but separate checks.

7. Review IP Rating and Environmental Conditions

Explosion protection does not automatically establish suitability for every environmental condition. Check the project requirements for:

  • Ingress protection (IP rating)
  • Corrosion resistance and enclosure material
  • Marine or offshore exposure
  • UV exposure and humidity
  • Mechanical impact resistance
  • Outdoor installation or washdown conditions
  • Salt-laden or chemically aggressive atmospheres

Best practice: Compare the datasheet's environmental ratings with the actual installation environment and project specification.

8. Verify the Certificate Against the Exact Model

One of the most important checks is confirming that the certificate covers the exact product being offered.

Compare the following information:

  • Manufacturer name
  • Product designation and model number
  • Certificate number and certification body
  • Ex marking and protection concept
  • Applicable standards and editions
  • Temperature and ambient ratings
  • Special conditions of use
  • Product variants covered by the certificate

Where IECEx certification is specified, check the relevant certificate details through the official IECEx website. For other certification schemes, use the applicable issuing body's documentation or database.

Procurement warning: Do not assume that two products are equivalent because their product names or marketing descriptions are similar. Confirm that the certificate covers the proposed model and configuration.

9. Review Special Conditions of Use

Some certified equipment is subject to special conditions that may affect installation, operation, or maintenance.

Depending on the product, these may concern:

  • Installation limitations
  • Temperature restrictions
  • Mechanical protection
  • Electrostatic considerations
  • Accessory compatibility
  • Mounting requirements
  • Restrictions applying to specific variants

Best practice: Review the complete certificate and manufacturer's instructions before technical approval. Identify any conditions that must be addressed by the supplier, installer, or project team.

10. Check Cable Entries and Accessories

The equipment enclosure is only one part of the installation. Cable glands, stopping plugs, adaptors, reducers, conduit entries, and other accessories must also be considered.

Verify:

  • Entry thread type and size
  • Number of entries and available space
  • Cable diameter range and gland requirements
  • Material compatibility
  • Certification requirements for accessories
  • Whether required accessories are included in the offer or supplied separately

Best practice: Review the complete proposed configuration, including accessories and installation arrangements, rather than evaluating the equipment body alone.

11. Confirm the Applicable Standard Edition

Check the standards and editions referenced in the project specification, datasheet, and certification documentation.

Do not automatically substitute a newer edition for the one specified by the project. Any change should be reviewed against the project engineering basis, applicable regulatory requirements, and certification documentation.

Best practice: Record the relevant standards and editions during technical evaluation and raise discrepancies for formal review.

12. Compare the Datasheet Against the RFQ Line by Line

For EPC procurement, a line-by-line compliance table provides a clearer technical record than a general statement such as "technically compliant."

RFQ requirement Vendor offer Document reference Compliance / comment
Hazardous area Proposed application suitability Datasheet / project documents Confirm against requirement
EPL and protection concept Proposed marking Certificate / marking Verify suitability
Gas or dust group Proposed group Certificate / marking Compare with requirement
Temperature class Proposed rating Certificate / marking Verify suitability
Ambient range Specified operating range Datasheet / certificate Compare with site conditions
IP rating Proposed rating Datasheet Compare with RFQ
Electrical ratings Voltage / frequency / power Datasheet Confirm compatibility
Certification Certificate and model Certificate / product documents Verify exact configuration
Accessories Included components Quotation / drawings Identify exclusions

Record each item as compliant, non-compliant, or requiring clarification. Document deviations instead of assuming that missing information indicates compliance.

Example: Why a Datasheet May Need Clarification

Suppose an RFQ requires equipment for a gas hazardous area with a defined EPL, gas group, temperature class, outdoor IP rating, and ambient temperature range.

The vendor submits a datasheet showing the required voltage, IP rating, Ex marking, and a certificate. The offer may appear compliant at first glance.

However, further review may reveal that:

  • The certificate covers a different model suffix.
  • The certified ambient range does not cover the site conditions.
  • The temperature class does not satisfy the project requirement.
  • The proposed cable-entry arrangement requires clarification.
  • Required accessories or documents are excluded from the offer.

This is why datasheet evaluation must be a document-to-requirement comparison rather than a simple product search.

Practical 12-Point Ex Equipment Review Checklist

Before approving the equipment, confirm the following:

  1. Hazardous area: Is the equipment suitable for the specified zone or location?
  2. EPL: Does it meet the required Equipment Protection Level?
  3. Protection concept: Is the protection concept suitable?
  4. Gas or dust group: Does the marking meet the project requirement?
  5. Temperature: Is the temperature class or maximum surface temperature suitable?
  6. Ambient: Does the certified ambient range cover site conditions?
  7. Electrical: Do the electrical ratings meet the specification?
  8. Environmental: Are IP rating, materials, and environmental ratings suitable?
  9. Certificate: Does certification cover the exact model and configuration?
  10. Marking: Does the equipment marking match its supporting documentation?
  11. Accessories: Are cable glands and other required accessories properly specified?
  12. Installation: Have special conditions and installation requirements been identified?

What Documents Should Procurement Request?

Depending on the equipment and project requirements, request the following from the vendor:

  • Completed technical datasheet
  • Product catalogue and technical specifications
  • Ex certificate and relevant annexes
  • Product and dimensional drawings
  • Installation and maintenance instructions
  • Ex marking information
  • Accessory details and certification where applicable
  • List of technical deviations, if any

The required document package should be defined in the RFQ or procurement specification.

Conclusion

Ex equipment procurement should not be reduced to the question, "Is this product Ex certified?" The more useful question is whether the exact proposed equipment, configuration, certification, marking, environmental ratings, and installation arrangement satisfy the complete project requirements.

A structured datasheet review connects the hazardous area classification with the protection concept, EPL, gas or dust group, temperature classification, ambient conditions, electrical ratings, certification, and installation requirements.

For engineering and procurement teams, this approach makes technical bid evaluation more consistent and helps identify deviations before they become delivery, installation, or commissioning problems.

Important Note

This article provides practical engineering guidance and does not replace the applicable IEC standards, project specifications, certification documents, regulatory requirements, or equipment manufacturer's instructions.

Verify all acceptance criteria against the applicable standard editions, project requirements, certification records, and actual installation conditions.

Reference Standards

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