ATEX Instrument Selection & Installation SOP
An ATEX instrument selection and installation SOP for classified hazardous areas: zone classification, a hard ATEX marking-verification gate, technical review, hazardous-area installation requirements, inspection and commissioning.
What the ATEX instrument selection & installation SOP process is
Insatech's other installation SOP, the Process Instrument Installation & Commissioning SOP, covers a specified, ordered instrument going into a customer's plant under ordinary safety practice. This chart exists because a subset of that work is not ordinary: the instrument is going into a zone where a spark from a loose gland or a wrongly rated enclosure can ignite a flammable atmosphere, and every step downstream of that fact has to change. The chart starts from "Determine hazardous-area classification (zone)" rather than an assumed answer, because the zone, Zone 0/1/2 for a gas atmosphere, Zone 20/21/22 for a combustible dust, is what every later check is measured against; "Define process requirements" happens only once that classification is fixed, not before it, so the requirements are being written for the area the instrument will actually sit in.
The chart's center of gravity is "ATEX marking matches zone, gas group and temperature class?", and it is drawn as a hard gate rather than a soft check for a reason: an instrument's ATEX marking, its protection type, gas or dust group, temperature class and IP rating, either covers the zone it is going into or it does not, and there is no partial credit. A mismatch does not get a risk-accepted workaround or a customer sign-off to proceed anyway; it routes straight to "Reject non-conforming equipment, request a correctly certified unit" and back through "Verify ATEX equipment certification against zone, gas group and temperature class" once the replacement arrives, however much that costs the schedule. The second decision, "Installation passes ATEX inspection?", exists for the same reason on the other side of the work: cable glands, earthing and cable routing that look fine to an untrained eye can still be wrong for the zone, so a fail routes to "Rework installation to correct inspection findings" and back through inspection again rather than into commissioning on an inspector's assumption that it will probably be fine.
Every row also carries a named owner and an hours figure through the built-in People and Workload columns. Oscar Lindqvist, Insatech's ATEX and hazardous-area safety specialist, owns the classification step, the certification gate and the inspection gate, so the workload panel can show, for a week with two hazardous-area jobs booked, whether his hours are realistically spread across both or quietly double-booked; Thomas Reid and Nadia Kessler's hours cluster in the "Installation" lane, where the hands-on cable and earthing work actually happens. Use this SOP for any instrument going into a classified zone, and use the plain Process Instrument Installation & Commissioning SOP for everything else, rather than running every installation through the stricter gate whether or not the area is classified.
What this flowchart covers
In this template
- Hazardous-area classification and requirements, from "Installation request received for a classified hazardous area" through "Determine hazardous-area classification (zone)" to "Define process requirements", so the zone is fixed before any certification check begins
- The certification gate: "Verify ATEX equipment certification against zone, gas group and temperature class" feeding the "ATEX marking matches zone, gas group and temperature class?" decision, which branches to "Reject non-conforming equipment, request a correctly certified unit" on any mismatch, with no exception for schedule pressure
- Technical review and installation requirements across the "Technical Review" and "Installation" lanes: "Technical review of installation design" and "Define installation requirements: cable glands, earthing and cable routing for the zone" before a single gland is fitted
- Field installation and the inspection gate: "Install instrument and wiring to hazardous-area requirements" followed by "Inspect installation against ATEX installation requirements" and the "Installation passes ATEX inspection?" decision, which routes a fail to "Rework installation to correct inspection findings" rather than a documented exception
- Documentation and commissioning: "Complete ATEX installation documentation", "Commission instrument and hazardous-area installation" and "Hand over ATEX compliance file to customer", the file an auditor or the customer's own safety authority will ask for
- Named owners and hours on every row via the People and Workload columns, so the workload BI panel can show Oscar Lindqvist's hours clustering across classification, certification and inspection while Thomas Reid and Nadia Kessler's hours cluster in the "Installation" lane
When to use this template
- You're installing or replacing an instrument in a customer's classified hazardous area (Zone 0/1/2 for gas, Zone 20/21/22 for dust) and need the certification and installation checks fixed on one chart instead of relying on the installing technician's own judgment
- A customer or their own safety authority is auditing a hazardous-area installation and wants to see the ATEX marking-verification step and the inspection step as documented, gated decisions, not an informal walk-through
- You're onboarding a new field technician or ATEX specialist and need a reference for exactly which checks happen before a cable gland is fitted and which happen after
- An instrument was rejected at the certification gate and you want a record of why, and what happened next, rather than an undocumented delay the customer only hears about after the schedule slips
- You're scoping a hazardous-area job against Insatech's ordinary Process Instrument Installation & Commissioning SOP and need to confirm which one applies before work starts
How it works
Replace the lanes with your actual hazardous-area roles
This chart uses Field Service, Engineering, ATEX Safety, QA and Commissioning. If a separate person independently signs off the certification gate from the person who performs the installation, split ATEX Safety into two lanes rather than folding the check into whoever happens to be on site.
Put your own marking-to-zone mapping on the certification gate
"ATEX marking matches zone, gas group and temperature class?" needs the actual protection type, gas or dust group and temperature class your zones require, not just "checked against the nameplate". Write the accepted marking directly into the row's comment field so the person verifying it isn't relying on memory.
Name who has the authority to call a reject
The certification decision is the one branch in this chart that cannot be overridden by schedule pressure. Attach a named role to "ATEX marking matches zone, gas group and temperature class?" so there's no ambiguity about who can send equipment back to procurement instead of letting it go into the ground.
Set People and Workload on every row before you rely on the BI panel
The workload panel can only total hours for rows that carry them. Fill in People and Workload for each step as you adapt the chart, using realistic effort hours rather than elapsed time, so a week with two hazardous-area jobs actually shows up as a busy week for the right specialist.
Decide what counts as an inspection fail
"Installation passes ATEX inspection?" is only useful if the inspector and the installing technician agree in advance on what triggers the Fail branch, an undersized gland, a missing bonding conductor, a barrier omitted from an intrinsically safe loop. List examples directly in "Rework installation to correct inspection findings" so the checklist isn't interpreted differently by whoever happens to be on duty.
Frequently asked questions
What triggers the start of the ATEX instrument installation process?
The process starts at "Installation request received for a classified hazardous area": an instrument is going into a zone where a flammable gas or combustible dust atmosphere can be present. That single fact is what pulls in every check that follows, and it is why the chart determines the zone before it defines a single process requirement.
What happens if the instrument's ATEX marking doesn't match the zone?
The "ATEX marking matches zone, gas group and temperature class?" decision routes a mismatch straight to "Reject non-conforming equipment, request a correctly certified unit", and the replacement goes back through certification verification once it arrives. There is no risk-accepted workaround: a marking that doesn't cover the zone is a hard stop regardless of schedule pressure.
Who has the authority to reject non-conforming equipment?
In this chart the certification gate sits with the ATEX Safety role, Oscar Lindqvist, not with whoever happens to be installing the instrument that day. Naming that authority explicitly is what keeps a technician under schedule pressure from making a call that belongs to the safety specialist.
Why does a failed inspection loop back instead of being logged as a noted exception?
"Installation passes ATEX inspection?" routes a Fail to "Rework installation to correct inspection findings" and back through inspection again, the same pattern as the certification gate. Cable glands, earthing and routing that look acceptable to an untrained eye can still be wrong for the zone, so the chart treats a fail the same way it treats a marking mismatch: fixed and re-checked, not noted and carried forward.
How is this different from Insatech's ordinary Process Instrument Installation & Commissioning SOP?
The ordinary SOP covers a specified instrument going into a customer's plant under standard practice. This one exists specifically for classified hazardous areas, and it adds two things the ordinary SOP doesn't have: the zone-classification step at the very start, and the ATEX marking-verification gate before installation even begins. Use this SOP whenever the installation site is a classified zone; use the ordinary one everywhere else.