Explosion-proof performance testing service

Explosion-Proof Performance Testing Service – Accredited Safety Assessment for Hazardous Area Equipment and Enclosures

For Bangladeshi importers, manufacturers, and project engineers in the oil & gas, chemical processing, pharmaceutical, mining, and power generation sectors, ensuring that electrical and non‑electrical equipment can operate safely in potentially explosive atmospheres is a legal and moral imperative. Our ISO/IEC 17025 accredited laboratory offers a comprehensive explosion-proof performance testing service that evaluates the integrity of enclosures, flamepaths, and ignition sources under simulated fault and explosion conditions. Using certified pressure vessels, gas‑mixing stations, and advanced measurement systems, we verify compliance with international standards such as IEC 60079, ISO 80079, and ATEX directives, as well as the technical requirements of the Bangladesh Standards and Testing Institution (BSTI), the Department of Explosives, and Petrobangla for hazardous area installations.

Product Samples We Regularly Test

We accept a broad range of equipment and components intended for use in Zone 0, 1, 2 (gas) and Zone 20, 21, 22 (dust) hazardous areas. Our test rigs accommodate everything from small junction boxes and sensors to large motors, control panels, and lighting fixtures. Common samples include:

• Flameproof enclosures (Ex d) – switchgear, junction boxes, motor starters, and lighting fittings.
• Increased safety equipment (Ex e) – terminal boxes, cable glands, and control assemblies.
• Intrinsically safe apparatus (Ex i) – sensors, transmitters, and handheld devices.
• Pressurised enclosures and purged systems (Ex p) – analyser shelters and control rooms.
• Non‑electrical equipment (Ex h) – valves, pumps, fans, and conveyor components.
• Dust‑ignition‑proof enclosures (Ex t) – for combustible dust atmospheres.
• Seals, cable entries, and conduit systems – including barrier glands and stopping plugs.
• Repaired or refurbished certified equipment – for re‑validation after modifications.

Enclosure Overpressure and Flamepath Integrity Testing

For flameproof (Ex d) enclosures, the ability to contain an internal explosion and cool escaping gases through flamepaths is paramount. Our explosion-proof performance testing service includes a suite of pressure and gap measurements that verify the integrity of the enclosure:

• Internal explosion pressure test (IEC 60079‑1, ISO/IEC 80079‑36, EN 60079‑1) – We pressurise the enclosure with a flammable gas mixture (e.g., hydrogen or acetylene in air) and ignite it using a spark plug or fuse wire. We measure the peak explosion pressure using piezo‑electric pressure transducers (sampling at > 50 kHz) at multiple points inside the enclosure. The test is repeated until the maximum pressure is established, and the enclosure must not exhibit any permanent deformation or rupture that would compromise its flamepath.
• Flamepath clearance and gap measurement (IEC 60079‑1, Annex C – using feeler gauges and optical comparators) – We measure the gap between the flamepath surfaces (flanges, shafts, and spigot joints) at several positions, using precision feeler gauges and, where necessary, optical microscopy. The measured gaps must be less than the maximum specified for the gas group (IIC < IIB < IIA) and the pressure class. We also verify the flamepath length (e.g., 25 mm minimum) and the surface roughness (Ra ≤ 6.3 µm) to ensure effective flame quenching.
• Static pressure and hydraulic proof test (IEC 60079‑1, ASME BPVC) – As an alternative to gas explosion testing (or as a preliminary screening), we pressurise the enclosure hydrostatically to 1.5 times the maximum expected explosion pressure and hold for 1 minute. Any leakage or permanent deformation indicates failure. This test is also used for enclosures that cannot be filled with gas (e.g., large compartments).
• Multiple‑explosion test (IEC 60079‑1, with 5 to 10 ignitions) – for flamepath assessment – We perform repeated explosions inside the same enclosure to verify that the flamepath surfaces do not become deformed or coated with carbon deposits that could prevent proper sealing. After each explosion, we re‑measure the flamepath clearance.
• Flamepath temperature rise measurement (using thermocouples and infrared thermography) – During and immediately after the internal explosion, we measure the temperature of the flamepath surfaces to ensure that the exiting gases are cooled below the auto‑ignition temperature of the surrounding atmosphere. A temperature rise above the allowable limit (typically +200°C for Group IIA) indicates inadequate flame quenching.

Internal Ignition Testing for Intrinsic Safety and Non‑Incendive Equipment

For intrinsically safe (Ex i) and non‑incendive (Ex n) equipment, the focus is on preventing ignition altogether. Our testing verifies that under fault conditions, the electrical and thermal energy remains below the ignition threshold:

• Spark ignition test (IEC 60079‑11, IEC 60079‑25) – We connect the apparatus to a certified spark‑test apparatus (tungsten or cadmium contacts) that simulates the opening and closing of circuits in a flammable gas atmosphere. We apply both normal and fault currents (e.g., short‑circuit, component failure) and count the number of ignitions over a defined number of operations (typically 1,000). A device passes if the number of ignitions is below the specified limit for the gas group.
• Hot‑surface ignition test (IEC 60079‑0, ISO 80079‑36) – using a temperature‑controlled oven – We place the equipment in an oven and raise the ambient temperature until the surface temperature of any component reaches the specified maximum (e.g., T4 = 135°C, T6 = 85°C). We then introduce the test gas (or dust) and observe whether ignition occurs. The equipment must not cause ignition at or below its rated temperature class.
• Energy‑limiting and current‑limiting verification (IEC 60079‑11, with oscilloscope) – We measure the voltage, current, and power output of the apparatus under normal and fault conditions using a high‑speed digital oscilloscope. The measured values are compared to the permissible energy limits for the gas group (e.g., 20 µJ for IIC).
• Component temperature measurement under fault conditions (IEC 60079‑0, IEC 60079‑7) – We apply short‑circuit or component‑failure conditions to the internal circuit and measure the temperature rise of critical components (semiconductors, resistors, coil windings) using thermocouples. The highest recorded temperature must not exceed the T‑code limit.
• Galvanic isolation and dielectric strength (IEC 60079‑11, IEC 60079‑7) – We apply a high‑voltage test (e.g., 1.5 kV for 1 minute) between the intrinsically safe circuit and the hazardous area, and between the IS circuit and any non‑IS circuits, to verify that no breakdown occurs that could allow energy to enter the hazardous area.

Pressurised Enclosure and Purging Systems (Ex p) – Gas and Air Integrity

For pressurised enclosures, we verify the integrity of the enclosure and the effectiveness of the purge system to prevent the ingress of flammable gases:

• Overpressure and leakage test (IEC 60079‑2, EN 60079‑2) – We pressurise the enclosure with clean air or inert gas to a specified pressure (typically 50‑200 Pa) and monitor the pressure drop over time. The leakage rate must be low enough to maintain the minimum protective pressure with the specified flow rate of the purge system. We also verify that the pressure relief devices operate at the correct set point.
• Purge flow and dilution test (IEC 60079‑2, ISO 80079‑36) – We measure the purge flow rate using a calibrated rotameter and verify that it is sufficient to reduce the internal concentration of flammable gases to below 25% of the LFL (lower flammable limit) within the specified purge time. We also test the automatic shut‑off or alarm systems that activate if the purge flow is interrupted.
• Leak tightness of cable entries and penetrations (IEC 60079‑2, using helium or pressure decay) – We seal the enclosure, apply a test pressure, and use a helium leak detector (or pressure decay monitoring) to identify and quantify leaks through cable glands, conduit entries, and housing joints. The cumulative leakage must be below the allowable limit for the pressurisation class.
• Verification of pressure switch and alarm set points (IEC 60079‑2) – We test the actual response of the pressure switches and alarms by gradually releasing pressure and recording the activation points, ensuring that they match the design settings and that there is an adequate safety margin.

Dust‑Ignition‑Proof (Ex t) and Dust Layer Testing

Combustible dust environments require specific tests to ensure that surface temperatures do not ignite dust layers or clouds. Our service covers both enclosure integrity and temperature rise assessment:

• Dust layer ignition temperature test (IEC 60079‑0, IEC 60079‑31, ASTM E2021) – We place the equipment on a metal plate and surround it with a layer of the specified dust (e.g., corn starch, coal dust, or metal dust) to a defined thickness (typically 5 mm). The equipment is operated at its rated power, and we monitor the temperature of the dust layer and the equipment surface. The maximum surface temperature must be below the minimum ignition temperature of the dust layer (LIT), with an appropriate safety margin (e.g., T‑code rating).
• Dust penetration and enclosure integrity (IEC 60079‑31, IP6X dust chamber) – We place the enclosure in a dust chamber filled with talcum powder (or specified dust) and agitate the dust to create a turbulent atmosphere. The chamber is operated for a defined duration (e.g., 8 hours), and then the enclosure is opened and inspected for any dust ingress into the internal cavity. Any visible dust inside constitutes failure.
• Surface temperature measurement under worst‑case dust accumulation (IEC 60079‑31) – We simulate dust accumulation by placing a layer of standardised dust on the top and side surfaces of the enclosure, and we operate the equipment at maximum ambient temperature and load. The surface temperature is measured at multiple points using thermocouples, and the highest reading must be less than the T‑code limit for the dust group (e.g., T6 = 85°C, T5 = 100°C, T4 = 135°C).
• Thermal stability of dust deposits – using oven test (ASTM D7409, ISO 6184) – We place a sample of the dust in an oven and raise the temperature at a controlled rate, recording the temperature at which exothermic oxidation begins (the onset temperature). This data is used to define the safe operating temperature margin for the equipment.
• Dust cloud and dust layer auto‑ignition temperature (ASTM E1491, ISO/IEC 80079‑20‑2) – We provide optional testing of the dust itself to determine its ignition temperature, which is essential for classifying the dust group and selecting the appropriate T‑code.

Mechanical and Environmental Robustness for Explosion‑Protected Equipment

Explosion‑proof equipment must also withstand mechanical shocks, vibration, and environmental extremes without losing its protective properties. Our testing covers these aspects:

• Impact resistance test (IEC 60079‑0, EN 60079‑0, using a 1 kg or 5 kg drop hammer) – We drop a mass from a specified height onto the enclosure (at the most vulnerable points, including the flamepath area) to simulate impact from falling objects or tools. The impact is performed at both room temperature and the minimum service temperature (e.g., ‑20°C). After the impact, we visually inspect for cracks and re‑measure the flamepath clearance.
• Vibration endurance test (IEC 60079‑0, IEC 60068‑2‑6) – We mount the equipment on a vibration table and subject it to a defined sinusoidal or random vibration profile (e.g., 5‑500 Hz, 2 g, for 2 hours per axis). We then check for mechanical looseness, cracked components, and perform a leakage test to ensure the enclosure remains gas‑tight.
• Ingress protection (IP) test for dust and water (IEC 60529, ISO 20653) – We verify the IP rating of the enclosure (e.g., IP66, IP67) using standard dust and water jet tests. For Ex equipment, a minimum rating of IP54 is typical, but higher ratings (IP66, IP67) are often required for outdoor or wash‑down areas.
• Low and high temperature endurance (IEC 60079‑0, IEC 60068‑2‑1, IEC 60068‑2‑2) – We condition the equipment at the minimum and maximum service temperatures (e.g., ‑40°C and +60°C) and then perform the overpressure, flamepath, or ignition tests at those temperatures to verify that the protection concepts remain valid over the entire operating range.
• Corrosion and salt fog resistance (IEC 60079‑0, ASTM B117, ISO 9227) – For offshore and coastal applications, we expose the equipment to salt spray for up to 500 hours, then re‑test the flamepath and mechanical integrity. We also inspect for any corrosion that could enlarge the flamepath gaps.

Non‑Electrical Equipment – Mechanical Sparks and Thermal Ignition

For non‑electrical equipment (e.g., fans, pumps, valves), ignition can occur from mechanical sparks or hot surfaces. We apply specialised test methods:

• Drop‑impact and friction ignition test (ISO 80079‑36, ISO 80079‑37, EN 13463‑1) – We simulate a mechanical failure (e.g., dropped part, rubbing of rotating components) using a specially designed test apparatus that creates contact between the equipment material and a standard steel or aluminium surface. We observe whether sparks are generated that could ignite the surrounding gas mixture.
• Temperature rise under blocked‑rotor or stalled condition (ISO 80079‑36, custom) – For rotating equipment (fans, pumps), we simulate a locked‑rotor condition and measure the surface temperature rise. The temperature must not exceed the T‑code limit for the ambient gas group.
• Electrostatic discharge (ESD) resistance for non‑metallic parts (IEC 60079‑0, ISO 80079‑36) – We measure the surface resistivity of plastic or non‑metallic components to ensure they are anti‑static (＜10⁹ Ω/sq). We also perform a discharge test using an electrostatic generator to verify that no incendive sparks occur.
• Mechanical shock and hammering test for manual tools (EN 13463‑1, ASTM D5628) – For hand tools used in hazardous areas, we subject them to controlled impact and friction tests to prove they do not produce sparks.
• Thermal insulation test – for equipment with hot internal surfaces (IEC 60079‑0, custom) – We verify that the thermal insulation or air gap between hot components and the enclosure surface is sufficient to prevent the external surface from exceeding the T‑code limit.

Documentation, Marking, and Compliance Verification

A crucial part of our service is verifying that the equipment’s marking, documentation, and instruction manuals meet the regulatory requirements for hazardous area use:

• Verification of nameplate marking (IEC 60079‑0, ATEX) – We check that the nameplate contains the mandatory information: Ex symbol, protection concept (Ex d, Ex e, etc.), gas group (IIA, IIB, IIC), temperature class (T1‑T6), IP rating, ambient temperature range, and certificate number. We verify that the markings are durable and legible after environmental conditioning.
• Assessment of technical documentation and instruction manual (IEC 60079‑0, ISO 80079‑36) – We review the manufacturer’s documentation to ensure it includes safe installation, operation, maintenance, and repair instructions, as well as details of the protection concept and any special conditions for use (X‑conditions).
• Material traceability and certification (for flamepath components) – We check the material test certificates (MTCs) for critical flamepath components (enclosure, flamepath plates, shaft materials) to verify that they meet the specified mechanical and corrosion‑resistant properties.
• Verification of components and sub‑assemblies – using approved parts list (IEC 60079‑0) – We cross‑reference the internal components (cable glands, switches, terminal blocks) against the manufacturer’s approved parts list to ensure no unauthorised substitutions have been made.
• Certificate and standard compliance check – ATEX, IECEx, BS, and local BSTI requirements – We map the test results against the specific requirements of the certification scheme applicable to your product, identifying any gaps that need to be addressed before final certification.

Post‑Test Reporting and Certification Support

Our reports provide a complete and auditable record of all tests, supporting your certification application (IECEx, ATEX, or local approval) and providing evidence for factory and site acceptance inspections:

• Detailed test procedures and setup photographs – We document the test arrangement, including the ignition source, pressure transducer locations, gas mixture composition, and any special fixtures used.
• Raw data from pressure transducers, thermocouples, and oscilloscopes – We include the complete pressure‑time and temperature‑time curves, allowing independent analysis if required.
• Calculated parameters and pass/fail determination against the specified standard – We clearly state whether the equipment meets the requirements of the relevant standard (e.g., IEC 60079‑1, IEC 60079‑11) and identify any deviations or non‑conformances.
• High‑resolution photographs and video of the explosion and equipment condition – We provide visual documentation of the test, including high‑speed video of the explosion, and annotated images of the equipment before and after the test.
• Recommendations for modifications (if failure occurs) and engineering guidance – If the equipment fails any of the tests, we provide a detailed explanation of the failure mode and specific recommendations for design changes (e.g., increasing flange thickness, improving flamepath finish, or adding pressure relief).

Report Accreditation and Compliance for Bangladesh

All explosion‑proof performance test methods described above are performed within our ISO/IEC 17025:2017 accredited quality management system, ensuring traceable calibration of pressure transducers, temperature sensors, gas analysers, and all mechanical measurement tools. Our test reports are recognised by the Bangladesh Standards and Testing Institution (BSTI) for product certification and import clearance, and they meet the technical documentation requirements of the Department of Explosives and Petrobangla for hazardous area equipment used in gas fields, refineries, chemical plants, and other major industrial installations. For export‑oriented manufacturers, our reports align with the requirements of IECEx and ATEX certification bodies, facilitating market access in the EU, the Middle East, and other regions. Each report includes a full description of the test conditions, the measured values, an analysis of the results, and a professional conclusion on whether the equipment is suitable for use in the specified hazardous area classification – giving you the confidence to meet your legal obligations, protect your workers, and ensure the safety of your operations.

Why Choose Our Explosion‑Proof Performance Testing Service

We understand that explosion protection is not just about compliance – it is about saving lives and preventing catastrophic loss. Our team provides rapid and responsive service, with flexible scheduling and clear communication throughout the test process. We work closely with your engineering and certification teams to understand the specific hazardous area classification (gas group, temperature class, zone), the intended installation environment, and any special conditions that may affect the equipment’s performance. Whether you are a manufacturer seeking type‑approval for a new product line, an importer verifying a shipment, or a plant operator performing periodic re‑certification, our explosion-proof performance testing service delivers the technical depth, regulatory expertise, and operational reliability you need. Contact us to discuss your equipment, the hazardous area classification, and the applicable standards – we will design a test programme that ensures your equipment is safe, compliant, and ready for the toughest environments.