Inspecting equipment in ATEX hazardous areas — Ex equipment register, marking, inspection grades and documentation

Short answer: an Ex nameplate combines Directive 2014/34/EU marking with the protection concept code from EN 60079. In II 2G Ex db IIC T4 Gb: the Ex hexagon marks a product for explosive atmospheres; II is the equipment group for non-mining use; 2 is the category; G means gas atmosphere (D is used for dust).

The rest describes construction: Ex db is a flameproof enclosure that withstands an internal explosion without transmitting flame (other common types are Ex eb increased safety, Ex ia/ib intrinsic safety and Ex tb dust protection by enclosure). IIC is the gas subgroup covering the most demanding gases such as hydrogen and acetylene; IIC equipment also suits IIB and IIA. T4 means surface temperature will not exceed 135°C. Gb is the equipment protection level (EPL) for zone 1.

The plate also shows the type examination certificate number, the ambient temperature range (often −20°C to +40°C) and possibly the letter X, meaning specific conditions of use set out in the certificate. X is one of the most often overlooked items — inspectors must check those conditions are actually met on site.

Short answer: the category must match the zone. Zones 0 (gas) and 20 (dust), where an explosive atmosphere is present continuously or for long periods, require category 1 equipment (EPL Ga or Da). Zones 1 and 21 allow category 1 or 2 (EPL Gb or Db). Zones 2 and 22, where an explosive atmosphere is rare and short-lived, allow category 1, 2 or 3 (EPL Gc or Dc).

Category is only the first condition. Equipment must also have the right subgroup (IIA, IIB, IIC for gas; IIIA, IIIB, IIIC for dust) and a temperature class below the auto-ignition temperature of the substance present. Substance data comes from the explosion protection document and safety data sheets, so the chemical register and the Ex register should reference each other.

The most common audit finding is equipment moved without checking its marking: a category 3 luminaire in zone 1, a IIB fan in a hydrogen room or an ordinary extension lead in zone 22. These usually arise during refurbishments, which is why they belong in a management of change process. Zone classification itself is covered in the guide to ATEX zones and site safety plans.

Short answer: EN 60079-17 defines three inspection grades. Visual inspection identifies defects visible without tools or opening the enclosure — missing bolts, damaged housings, illegible plates. Close inspection adds items needing access equipment or simple tools — gland tightness, seals, bonding. Detailed inspection requires opening the isolated enclosure to check the interior, terminals, flamepaths and measurements such as insulation resistance.

The standard also defines inspection types: initial inspection before commissioning (always detailed), periodic inspections and sample inspections of part of the equipment. Inspection after repair or reconfiguration is treated as initial inspection of the changed item.

Opening an explosion-protected enclosure in a hazardous area is high-risk work. A detailed inspection first requires isolation under a LOTO procedure and, in many plants, a permit to work with gas testing before opening.

Short answer: there is no single legal interval. EN 60079-17 states that the interval between periodic inspections should not exceed 3 years without expert advice; the actual interval depends on equipment type, manufacturer guidance, environment (corrosion, vibration, dust, temperature) and previous results. Poor results shorten it; consistently good results may extend it within the standard.

An alternative to periodic inspection is continuous supervision by skilled personnel who regularly attend the installation, know the equipment and record its condition. It requires documented competence, scope and records — it reorganises inspection rather than replacing it.

Ex inspections do not replace other tests. The electrical installation still needs periodic shock-protection and insulation measurements, machinery needs manufacturer-defined checks and pressure or lifting equipment needs statutory examinations. Keep all of them in a single inspection register to avoid duplicate site visits.

Short answer: in Poland, work on electrical equipment requires a qualification certificate under the 1 July 2022 regulation on qualifications for operating equipment, installations and networks. The electrical group lists explosion-protected electrical equipment and installations as a separate scope — the certificate should explicitly include it, for operation (E) or supervision (D).

EN 60079-17 additionally requires inspections by skilled personnel who know protection concepts, installation practice, zone classification and documentation requirements, with periodic refresher training. Many plants also expect a competence certificate such as IECEx, although Polish law does not require it.

Repair and overhaul of Ex equipment — especially flameproof enclosures and motors — follows EN 60079-19, ideally at the manufacturer or a workshop equipped for such work. A repair that changes flamepath dimensions can void explosion protection even if the equipment still runs.

Short answer: the verification dossier, required by EN 60079-14 and used for inspections under EN 60079-17, gathers everything that proves the installation is fit for the zone: the zone classification with subgroup and temperature class, the Ex equipment list with locations, EU declarations and certificates, manufacturer instructions, intrinsically safe loop documentation, initial and subsequent inspection records and the qualifications of the people who did them.

At its heart is the Ex equipment register — each item with an ID, location, zone, full nameplate marking, certificate number, installation date, grade and date of last inspection, result, next due date and repair history. A spreadsheet register quickly goes stale as equipment is moved, replaced or repaired.

The register links to the explosion protection document: the document describes zones and measures, the register proves the installed equipment matches them. Review one whenever the other is updated.

In the Registers and inspections module each Ex item has a card with its full nameplate marking, certificate number, zone and an inspection schedule split into visual, close and detailed grades. The software sends reminders, stores reports, photos and manufacturer documents and shows repair history. Inspector qualifications can be kept in training and qualification records so it is clear whether a certificate covering explosion-protected equipment is valid.

In the Plans and zones module equipment is placed on the site plan together with zone 0, 1, 2 and 20, 21, 22 boundaries. One plan shows where an item stands, which zone it works in and its inspection status, making it easier to plan rounds and compare equipment category with zone requirements. A QR code or NFC tag from the access points module on the enclosure lets the electrician open the item card on site and record the result.

Work that requires opening an enclosure can be linked to the permit to work module. The software organises deadlines and documents but does not judge for people: equipment selection, inspection results and fitness-for-use decisions remain with qualified staff.