Skip to content 
Selecting an explosion-proof luminaire is only the first step in designing a reliable hazardous-area lighting system. For oilfield maintenance areas, engineers must also verify that the lighting layout matches the approved hazardous-area classification, provides clear visibility for maintenance tasks, and can be safely installed and maintained throughout the project lifecycle.
A lighting system may use certified equipment but still fail to support real field operations if factors such as mounting position, beam distribution, shadows, glare, and installation details are not properly considered.
This guide provides a practical checklist for reviewing Zone 1 and Zone 2 lighting layouts, covering the key engineering and procurement considerations from project documentation and equipment selection to installation and commissioning.
What Documents Should Be Verified Before Reviewing a Hazardous-Area Lighting Layout?
A reliable hazardous-area lighting review starts before any explosion-proof luminaire is selected. Lighting software cannot compensate for incomplete or inaccurate engineering inputs.
First confirm that the project documents provide a clear design basis. Beam angles, fixture positions, and calculations can then be checked against approved project information instead of assumptions carried over from another job.
Confirm the Hazardous-Area Classification
The hazardous-area classification drawing is the starting point for an explosion-proof lighting project. It shows where hazardous atmospheres may occur and defines the equipment requirements for each location.
Check that the lighting proposal uses the latest approved classification documents.
A name such as pump station, compressor area, or maintenance platform does not determine the classification. Similar equipment can fall into different zones because process conditions, ventilation, and the likelihood of an explosive atmosphere differ.
Best Practice: Use the approved hazardous-area classification drawing as the design reference. Do not assign a zone from an equipment name or a previous project.
Review the Engineering Design Documents
Area classification is only part of the design basis. The review should also cover documents that show the facility arrangement and the maintenance work to be performed.
Typical documents include:
- Hazardous Area Classification Drawing
- Area Classification Report
- Piping and Instrumentation Diagram (P&ID)
- General Arrangement (GA) Drawing
- Equipment Layout Drawing
- Cable Routing Drawing
- Owner or Operator Specifications
Read together, these documents show equipment positions, access routes, structural obstructions, and installation constraints that can affect the layout.
Understand the Maintenance Tasks
The layout must support the work technicians perform, not merely light the surrounding area.
Identify the equipment and maintenance activities that require clear visibility before reviewing the layout.
Typical maintenance tasks include:
- Reading pressure gauges
- Operating valves
- Inspecting flange connections
- Opening junction boxes
- Checking instrument panels
- Servicing pumps and motors
These tasks take place at specific working positions and often depend on visibility across vertical or angled surfaces, not just the floor.
A useful review therefore starts with two practical questions: where will the technician stand, and what must be visible from that position?
Define the Project Requirements
Operating conditions and technical requirements vary by project. Confirm them before evaluating the lighting equipment.
Key considerations include:
- Hazardous zone classification
- Gas group
- Temperature class
- Ambient operating conditions
- Corrosive environment
- Mechanical impact risks
- Project-specific owner requirements
These factors affect equipment selection and determine which supporting documents procurement will need.
Key Takeaway
Start the review with the project documents, not the fixtures. Confirm the area classification, engineering drawings, maintenance tasks, and project requirements before assessing equipment or the layout.
What Determines Whether an Explosion-Proof Luminaire Is Suitable?
A Zone 1 or Zone 2 marking alone does not establish suitability. The luminaire must match the area classification, operating environment, and project requirements, and its documentation must support engineering and procurement review.
Before approval, verify the product against the application and certificate scope rather than treating the presence of an explosion-proof certificate as sufficient.
Confirm the Hazardous-Area Classification
Equipment selection should always begin with the approved hazardous-area classification.
The classification drawing shows where explosion-protected equipment is required and sets the basis for selecting its protection level. Do not assume that similar process units share a classification: ventilation, process conditions, and release sources may differ across the facility.
Use the latest approved project documents when reviewing the equipment.
Verify the Gas Group and Temperature Class
Zone classification is only one part of the suitability check.
The luminaire must also match the specified gas group and temperature class in the project requirements.
When reviewing a product, verify that the following information is consistent across the technical documentation:
- Product nameplate
- Certification documents
- Product datasheet
- Supplier quotation
Resolve any inconsistency before procurement.
Evaluate the Operating Environment
Explosion protection is not the only demand placed on lighting in an oilfield maintenance area.
Engineers should consider factors such as:
- High or low ambient temperatures
- Rain and water exposure
- Dust accumulation
- Corrosive atmospheres
- Offshore salt spray
- Mechanical vibration
- Potential impact from maintenance activities
These conditions affect service life and may limit the available configurations. Compare the actual site conditions with the supplier’s technical documentation before accepting the luminaire.
Don’t Confuse Explosion Protection with IP Protection
A high IP rating does not make a product suitable for a hazardous area. IP and explosion-protection markings address different risks.
| Requirement | What It Protects Against |
|---|---|
| Explosion Protection | Prevents the equipment from becoming an ignition source in a hazardous atmosphere. |
| IP Rating | Protects against dust and water ingress. |
| Corrosion Resistance | Improves durability in aggressive industrial environments. |
| Mechanical Protection | Helps withstand vibration, impact, and physical damage. |
Check every applicable requirement; no single rating is enough on its own.
Verify the Supporting Technical Documentation
The documentation must identify the same equipment used in the lighting design. Otherwise, procurement cannot confirm that the quoted or delivered product matches the calculation.
Before approving a supplier, request documentation such as:
- Product datasheet
- Explosion-proof certificate
- Certificate schedule
- Installation manual
- IES or LDT photometric file (if available)
- Product dimensions and mounting information
A complete document set supports engineering review and prevents avoidable questions during installation and commissioning.
Review Any Proposed Product Substitutions Carefully
Lead times, availability, or cost may prompt a substitution, but products that look similar can have different certification, optics, dimensions, or mounting arrangements.
Before accepting an alternative model, verify that it provides equivalent:
- Hazardous-area certification
- Gas group and temperature class
- Optical distribution
- Mounting arrangement
- Overall dimensions
- Operating environment ratings
If any characteristic changes, the original calculation may no longer describe the installed system. Send the proposed substitute back for engineering review before it is ordered.
Key Takeaway
Do not approve a luminaire on its Zone 1 or Zone 2 marking alone. Check the classification, gas group, temperature class, environmental limits, and supporting documents before procurement, and subject any substitute to the same review.
How Should the Lighting Layout Be Reviewed?
After confirming product suitability, review whether the layout gives technicians enough visibility for the work. Fixture count and average illuminance do not show how pipes, structures, and working positions affect the light reaching the task.
A layout can meet a calculation target yet still leave glare, shadows, or blind spots around the equipment.
Focus on Maintenance Tasks, Not Just the Floor
Area calculations often emphasize the floor plane, while technicians work on valves, gauges, panels, pumps, and junction boxes.
When reviewing a lighting layout, ask:
- Where will technicians stand?
- Which components require clear visibility?
- Are important work surfaces vertical, horizontal, or angled?
- Will equipment be opened during maintenance?
Judge the light at the task and from the normal working position, not only by uniformity across the surrounding area.
Verify Mounting Height and Beam Distribution
Mounting position directly affects coverage, glare, and the light reaching the task.
Mounting too high can widen coverage while leaving equipment poorly lit. Mounting too low can create glare, narrow the coverage, or expose the fixture to damage.
The beam distribution must also suit the application.
| Maintenance Area | Lighting Consideration |
|---|---|
| Pipe racks | Focused beam to illuminate narrow working spaces |
| Maintenance platforms | Wider distribution for broader coverage |
| Pump skids | Balanced lighting from multiple directions |
| Control panels | Controlled beam to improve visibility and reduce reflections |
Catalog beam images are only a starting point. Use the relevant photometric data to check the selected optic against the maintenance task and equipment arrangement.
Identify Shadows and Physical Obstructions
Pipe racks, structural steel, cable trays, vessels, and adjacent equipment often obstruct light in oilfield maintenance areas.
Average illuminance may look acceptable even when those obstructions leave the actual task in shadow.
During the design review, consider whether nearby structures could affect:
- Valve operation
- Gauge reading
- Equipment labels
- Junction boxes
- Flange inspections
- Access platforms
Finding these shadows during design avoids fixture relocation after commissioning.
Consider the Technician’s Viewing Angle
Check the layout from the technician’s working position, not only on the plan drawing.
A technician may stand beside machinery, reach overhead, or work in a confined space. With light arriving from one direction, the technician or nearby equipment can shade the task.
Reviewing several realistic viewing angles can reveal where a fixture should be moved, re-aimed, or supplemented.
Reduce Glare Without Sacrificing Visibility
More light is not automatically safer. Direct or reflected glare can obscure instruments and equipment details, particularly around stainless steel, painted enclosures, and wet surfaces.
Common sources of glare include:
- Direct view of high-output luminaires
- Reflective metal surfaces
- Wet equipment after rain or cleaning
- Fixtures installed within the normal line of sight
Provide enough task visibility without placing harsh sources or reflections in the technician’s normal line of sight.
Review the Layout Under Maintenance Conditions
Maintenance changes the scene on which the original layout was based.
For example:
- Control cabinet doors may remain open.
- Pump guards may be removed.
- Temporary scaffolding may block existing light.
- Portable tools and lifting equipment may create additional obstructions.
These temporary conditions can redirect or block light. Include the expected maintenance configuration in the review instead of assessing normal operation alone.
Key Takeaway
Judge the layout by the visibility it provides at maintenance tasks. Check mounting height, optics, shadows, viewing angles, glare, and obstructions before procurement; correcting them on the drawing is easier than modifying the installation later.
What Should Be Checked Before Procurement and Installation?
A sound layout can still fail in practice if procurement orders a different configuration or installation departs from the approved design.
Before the purchase order or installation begins, confirm that the equipment, documents, accessories, and installation method match the approved lighting design.
Verify That the Delivered Product Matches the Approved Design
The product delivered to site must match the product used in the lighting calculation.
Before procurement, confirm that the following information is consistent across all project documents:
- Product model number
- Explosion-proof certification
- Optical distribution
- Mounting configuration
- Operating voltage
- Accessories included in the quotation
A change in optic or mounting option can alter the distribution enough to affect the system performance.
Best Practice: Compare the lighting calculation, datasheet, quotation, and purchase order side by side. Each should identify the same product configuration.
Check Installation Accessories
The luminaire is only one part of the installation. Its accessories must also suit the application and the approved design.
During the procurement review, verify items such as:
- Cable glands
- Cable entries
- Blanking plugs
- Mounting brackets
- Fasteners
- Earthing hardware
An incompatible accessory can stop installation and trigger another engineering review.
Consider Temporary Maintenance Lighting
Permanent lighting may not cover every maintenance condition.
For example, technicians may need portable explosion-proof luminaires when:
- Equipment is isolated for maintenance.
- Control cabinets remain open.
- Temporary scaffolding blocks existing lighting.
- Large components create new shadows.
- Maintenance is performed in confined or difficult-to-access locations.
Where temporary lighting is expected, the project procedure should state how portable equipment will be powered, positioned, secured, and removed under safe working conditions.
Prepare for Commissioning and Inspection
Commissioning is the last formal check that the installed system matches the approved design.
Typical inspection activities include:
- Confirming fixture locations
- Verifying mounting height and orientation
- Checking cable entries and installation quality
- Inspecting for visible damage
- Confirming equipment identification
- Reviewing project documentation
Resolve any departure from the approved design before placing the system in service.
Procurement and Installation Checklist
Before handover, verify the following:
☐ Product model matches the approved lighting design.
☐ Certification and technical documentation are complete.
☐ Installation accessories are compatible with the selected equipment.
☐ Temporary maintenance lighting requirements have been considered.
☐ Fixture locations and orientations have been verified.
☐ Installation quality has been inspected.
☐ Commissioning records have been completed and approved.
Key Takeaway
The approved design must survive procurement, installation, and commissioning. Verify the ordered configuration, compatible accessories, fixture position, and commissioning records before handover so the installed system can be traced back to the engineering documents.
Hazardous-Area Lighting Review Checklist
A hazardous-area lighting review crosses engineering, procurement, installation, and commissioning. An incorrect configuration, missing document, or unsuitable mounting arrangement can send the project back for redesign or delay work on site.
Use this consolidated checklist during design review, supplier evaluation, purchase approval, or pre-commissioning inspection. It records the points that should be checked against the approved project requirements.
1. Project Documentation
Confirm the engineering basis before reviewing the layout.
☐ Hazardous Area Classification Drawing has been approved.
☐ Area Classification Report is available.
☐ P&ID and General Arrangement Drawings have been reviewed.
☐ Equipment locations and maintenance access have been confirmed.
☐ Project-specific owner or operator requirements have been identified.
2. Equipment Selection
Check the selected explosion-proof luminaire against the application.
☐ Hazardous zone matches the project classification.
☐ Gas group is compatible with the classified area.
☐ Temperature class meets project requirements.
☐ Ambient operating conditions fall within the product specification.
☐ Explosion protection, IP rating, corrosion resistance, and mechanical protection have all been reviewed.
3. Lighting Layout Review
Check the arrangement against the maintenance work it must support.
☐ Critical maintenance work areas have been identified.
☐ Mounting height is appropriate for the application.
☐ Beam distribution matches the equipment layout.
☐ Pipe racks, structural steel, and other obstructions have been considered.
☐ Shadows and glare have been minimized.
☐ Lighting has been reviewed from the technician’s working position.
4. Procurement Verification
Before ordering, confirm that the technical and commercial documents describe the same approved configuration.
☐ Product model matches the approved lighting design.
☐ Product datasheet has been reviewed.
☐ Explosion-proof certification has been verified.
☐ Installation manual is available.
☐ IES or LDT photometric file (where applicable) matches the selected product.
☐ Supplier quotation matches the approved configuration.
5. Installation and Commissioning
Before handover, inspect the installation against the approved design.
☐ Installation accessories are compatible with the selected luminaire.
☐ Fixture locations and orientations have been inspected.
☐ Cable entries and mounting hardware have been installed correctly.
☐ Visible damage or installation defects have been checked.
☐ Commissioning records have been completed.
☐ Final inspection confirms that the installed system matches the approved engineering documentation.
A Structured Review Helps Reduce Project Risk
Hazardous-area lighting depends on coordination across engineering, procurement, installation, and commissioning. Each team needs to work from the same approved design and equipment configuration.
A consistent checklist exposes mismatches while they are still relatively simple to correct, before they become purchase-order changes or site modifications.
The same review method applies to a new installation or an upgrade: establish the design basis, verify the equipment, test the layout against maintenance tasks, and inspect the finished work.
Why Choose Hexlon for Explosion-Proof Lighting Projects?
Product selection is only one part of the job. Engineering teams also need clear technical documents, configuration details, and timely answers during review.
Hexlon supplies explosion-proof lighting for oil and gas, petrochemical, and other hazardous-area applications. Our engineering team can provide product information, configuration guidance, and supporting documents during selection and review.
Available documents depend on the product series and project scope. They may include datasheets, installation manuals, dimensional drawings, and other technical information needed for evaluation.
For a new installation or an upgrade, send us the area classification and project requirements so we can identify options for engineering review.
Conclusion
A Zone 1 or Zone 2 lighting review goes beyond checking for an explosion-proof certificate. Approval should cover the project documents, product suitability, task-level layout, procurement records, accessories, and installation quality.
A disciplined review keeps the specified, ordered, and installed configurations aligned and gives the project team a clear record for handover and future maintenance.
