Refinery Drone Inspection Checklist: ATEX Zones, Flares, Tanks and Permits (2026)

Before a drone flies inside a refinery fence, confirm six things: the hazardous-area classification of every zone on the route and whether the aircraft is certified for it (most are not), a site permit-to-work, an aviation approval, a payload matched to each asset, an emergency plan, and a data path that respects the site's security rules. The checklist below walks through each, then goes asset by asset — flare stacks, tanks, columns, piping, pipelines and the fence line — and ends with who supplies which piece.

Disclosure: Dronehub builds drone-in-a-box infrastructure for fixed-site inspection, including at energy and industrial sites. This checklist is vendor-neutral; we name our own product only where it is relevant and say so.

The checklist at a glance

Hazardous areas come first

Directive 1999/92/EC makes the site classify its areas: Zone 0 where an explosive gas atmosphere is present continuously, for long periods or frequently, Zone 1 where it is likely to occur occasionally in normal operation, and Zone 2 where it is not likely and would be short-lived. It then sets which equipment category may be used — category 1 or 2 in Zone 1, category 1, 2 or 3 in Zone 2. Directive 2014/34/EU governs the certification of that equipment. US facilities classify locations under the National Electrical Code, for example as Class I, Division 1 or 2 — Division 1 where ignitable concentrations may exist in normal operation, Division 2 where they would appear only through an accident or unusual condition.

Ex-certified aircraft remain rare. When trade press covered Xamen's LE 4-8X in 2016, it was approved for Zone 2, with a Zone 1 version still in development. That leaves three workable patterns:

• Fly outside classified areas, observing zones from a standoff with zoom and thermal payloads. This covers most external inspection.
• Treat any entry into a zone as ignition-source work under the permit-to-work system: gas testing, continuous monitoring, a defined abort criterion.
• Use Ex-certified ground robots for routine rounds inside Zone 1. ANYbotics' ANYmal X is approved under IECEx and ATEX for Zone 1, and ExRobotics' ExR-2 robot and its docking station carry ATEX and IECEx Zone 1 certificates.

The same logic applies to docks. A drone-in-a-box is electrical equipment: site it outside classified zones unless it carries an Ex certification for the zone in question.

Permits and approvals

Aviation. In the EU, beyond-visual-line-of-sight (BVLOS) inspection needs the specific category under Regulation (EU) 2019/947, with a SORA-based authorisation; line-of-sight work fits the open category only if all its limits can be met. In the US, Part 107 applies and BVLOS needs a waiver; the proposed Part 108 is still pending. Refineries can sit close to airports and inside controlled airspace, so check the airspace for every route.

Flight restrictions. The FAA's proposed Section 2209 rule, published on 6 May 2026 and not yet final, would let refineries that convert crude oil and can produce 100,000 barrels per day or more apply for an unmanned aircraft flight restriction over their site. As drafted, even certificated Part 107 flights could only transit such an area unless the FAA authorises otherwise — so a refinery that applies should plan how its own inspection flights will be authorised.

Site permits. Drone flights inside the fence belong in the permit-to-work system like any other work: simultaneous-operations checks with operations and maintenance, notification to the control room, radio-frequency coordination, and a recovery plan if the aircraft comes down inside a unit.

Industry guidance. Two documents are worth adopting as the baseline: the Energy Institute's EI 3624 (April 2026), good-practice guidance for UAV visual inspection of high-hazard assets, and IOGP's Report 696 on managing remotely piloted aircraft operations, whether run directly or through contractors.

Asset by asset

Flare stacks are the classic drone job. Cyberhawk, an inspection service firm, inspects onshore stacks and offshore flares by drone without scaffolding, and uses thermal cameras to highlight overloads, insulation failures and leaks. The biggest gain is timing: when Cyberhawk inspected a live flare stack at a Scottish refinery in 2011, knowing its condition before the shutdown let the client scope the repairs and order long-lead spare parts in advance.

Tanks are driven by API 653, which requires a visual external inspection by an authorized inspector at least every five years, or sooner where corrosion demands it, with the tank allowed to stay in service. A drone gives that inspector the roof and upper shell without a climb. Internal work is different: Flyability's Elios 3 is designed for visual and thermal inspection inside confined spaces with no human entry, but the space is still a permit-required confined space under rules such as OSHA 1910.146 until it has been made safe.

Contact inspection fills the gap where a picture is not enough. Voliro's Voliro T applies up to 30 N of stable force for drone-based non-destructive testing, including on assets in service.

Pipelines leaving the fence have a clear US answer: PHMSA's interpretation says the right-of-way patrols required by § 195.412(a) — at least 26 a year — may use drones if the images have enough resolution to show surface conditions.

Gas detection payloads

Regulatory acceptance is growing but source-specific. In the US, Percepto says the EPA approved its autonomous OGI drone system as an alternative test method under subparts OOOOa and OOOOb — rules for the oil and gas production and transmission chain rather than refineries. In the EU, the Methane Regulation (EU) 2024/1787 covers production, transmission, distribution, storage and LNG, while methane from refining falls under the Industrial Emissions Directive. Check which rule governs each unit before you buy a payload for compliance surveys.

Emergency procedures and radio coordination

Write these down before the first flight, not after the first incident:

• Lost link. Define the return route and the holding point for every mission, and make sure neither crosses a classified zone.
• Aircraft down inside a unit. Who is told, who may enter to recover it, and whether a battery fire in that area triggers the site's fire response.
• Plant alarms. A gas alarm, a flaring event or an emergency shutdown should end the flight automatically or by instruction from the control room.
• Radio. Plant wireless instruments, handheld radios and drone command-and-control links can share spectrum. Agree a frequency plan with the site's telecom team and test it before routine flights.
• Weather and flare state. Set wind limits per asset, and a rule for what happens when a flare's heat load changes mid-mission.

Operating models

Most refineries combine three:

1. Campaign inspections by specialist contractors, timed around turnarounds — flares, tank internals, columns.
2. Persistent docked drones for recurring work: flare monitoring, tank-farm thermal surveys, fence-line patrols, leak surveys and post-incident look-sees at night.
3. Ex-certified ground robots for routine operator rounds inside Zone 1.

Dronehub works in the second model. Our energy and critical-infrastructure pages list refinery flare-stack monitoring, tank-farm thermal surveys, fence-line condition and leak detection with thermal and visible-spectrum imaging among the jobs for our drone-in-a-box. The dock re-arms the aircraft with a two-minute robotic battery swap, is designed for 24/7 operation and an operating range of −20 to +45 °C, and keeps imagery on EU and US infrastructure. On why the swap matters for repeated flights per shift, see battery swap versus in-station charging.

Who supplies what

Companies are listed by what each describes on its own website and grouped by role; this is not a ranking.

Data handling

Refinery imagery shows the layout, the security measures and the weak points of a facility that governments treat as critical infrastructure. Decide where the imagery is hosted and who can access it before the first flight, keep an audit trail, and delete raw footage once the findings are recorded. Findings are only useful when they land in the inspection programme: tag each one to an equipment number, attach it to the API 510, 570 or 653 record, and let the risk-based inspection plan decide what happens next. Our note on edge and cloud inference covers keeping processing close to the aircraft.

Where to start

Start outside the classified areas with the jobs that currently need scaffolding, rope access or a shutdown: flare tips, tank roofs, column tops. Measure each against the method it replaces — time, cost, access risk and the quality of the finding — and bring the permit-to-work owner into the first flights rather than the last. Move to docked, recurring flights only once the routes, permits and data path are proven, and use ground robots where the work sits inside Zone 1.

For a wider view of the energy sector, read energy grid and AI inspection; to scope a refinery deployment, talk to us.