How to use this checklist
Build a traceable in-service pressure-equipment file that shows what equipment is covered, why each inspection interval was selected, who made the technical decisions, what was examined, how remaining life was assessed and whether repairs or changes are fully documented.
Use it when
- Reviewing an air receiver, pressure vessel, boiler or associated pressure equipment inspection file.
- Preparing for external, internal or on-stream examination.
- Checking whether thickness data supports a corrosion-rate and remaining-life decision.
- Reviewing a repair, modification, alteration, re-rating or relocation package.
Do not use it to
- Applying one inspection frequency to all pressure equipment regardless of service and damage mechanism.
- Treating a generic NDT certificate as proof that the correct areas were examined.
- Calling someone a competent person based only on job title without checking relevant knowledge and experience.
- Replacing statutory registration, design verification, inspection-body or jurisdiction-specific requirements.
Stop and escalate when
These conditions deserve an explicit competent-person decision rather than being treated as routine checklist gaps.
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The equipment identity, design pressure/temperature, material or verified design basis cannot be established.
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Inspection is overdue or a deferral exists without a documented competent-person basis.
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Measured wall is at/below the verified minimum or remaining life is uncertain.
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Cracking, bulging, leakage, severe corrosion, overheating or other active damage is found.
!
A repair, modification, alteration, re-rating or relocation occurred without a clear engineering and inspection record.
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Working checklist
Your assessment is stored in this browser. Assign an explicit outcome, record the evidence behind it, and capture actions for every gap or unclear item.
Assessment record
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1. Establish the equipment and design basis
A useful inspection program starts with a uniquely identified item and enough design information to know what condition is acceptable.
Confirm unique asset identity, location, owner/controller and current service.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forNameplate, plant register, P&ID/location drawing and ownership/control record.Typical gapInspection reports use a local nickname that cannot be matched to the registered asset or drawings.Escalate whenTwo similar vessels could be confused or the inspected item cannot be uniquely identified.Source basisAS/NZS 3788:2024 equipment lifecycle and owner/control framework.Record current design and operating pressure, temperature, contents and operating envelope.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forVerified design data, nameplate, operating trends and relief settings.Typical gapThe inspection file contains nameplate pressure but no evidence of actual service temperature or process changes.Escalate whenCurrent operation exceeds or differs materially from the verified basis.Source basisAS 1210 design basis and AS/NZS 3788 in-service assessment framework.Collect the verified design calculations/drawings and identify the minimum required thickness basis at critical locations.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forDesign report with calculation references, drawings and any later re-rating/assessment.Typical gapUT data exists but no one knows the minimum acceptable wall used to judge it.Escalate whenRemaining wall cannot be compared with a verified acceptance basis.Source basisAS 1210 design record and AS/NZS 3788 integrity-assessment requirements.Confirm material specifications and pressure-boundary construction records are traceable.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forMaterial certificates, heat/part traceability and fabrication dossier.Typical gapReplacement plate or nozzle material is described only as 'equivalent'.Escalate whenMaterial properties needed for assessment cannot be established.Source basisAS 1210 manufacturing documentation and AS/NZS 3788 lifecycle records.Record known damage mechanisms and locations expected to be most susceptible.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forCorrosion review, service history, previous reports and process/material information.Typical gapA fixed UT grid is repeated without asking whether the damage mechanism has changed.Escalate whenDamage is localised, cracking is credible or the inspection method is poorly matched to the mechanism.Source basisAS/NZS 3788:2024 inspection planning based on credible deterioration mechanisms.02
2. Check the inspection plan and due dates
Inspection frequency should be traceable to an applicable profile, service condition, damage mechanism and competent-person decision—not copied from a generic calendar.
Identify the applicable inspection profile, table, regulatory rule, OEM requirement or risk-based basis for this item.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forInspection plan citing the applicable AS/NZS 3788 pathway and any jurisdiction/OEM requirements.Typical gapThe CMMS says 'annual' with no explanation of what examination is required or why.Escalate whenNo defensible basis exists for the selected interval.Source basisAS/NZS 3788:2024 inspection planning and interval framework.Record last completed external, internal/on-stream and safeguarding-device inspections separately.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forReport numbers, dates and next due dates by inspection type.Typical gapOne overall 'inspection date' hides that the internal examination or relief-device test is overdue.Escalate whenAny required inspection type cannot be traced to a completed report.Source basisAS/NZS 3788:2024 separate examination and safeguarding-device requirements.Check extended intervals or deferrals have a documented competent-person assessment and defined conditions.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forDeferral/extension report, risk basis, monitoring controls, expiry date and approval.Typical gapThe due date is changed in the CMMS without a technical assessment.Escalate whenInspection is overdue and no valid deferral basis can be produced.Source basisAS/NZS 3788:2024 extended interval and allowable deferral provisions.Confirm new damage or changed service feeds back into the inspection plan.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forRevised interval/method decision after corrosion, cracking, process or operating changes.Typical gapThe same interval continues after a new deterioration mechanism is found.Escalate whenDamage rate is increasing or the selected method no longer provides adequate coverage.Source basisAS/NZS 3788:2024 condition-responsive inspection planning.03
3. Confirm the competent-person basis
Competence is task-specific. The person selecting an interval, conducting an NDT method and accepting a repair may need different evidence of training, qualifications and experience.
Identify who is responsible for the inspection plan and integrity decisions.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forNamed person, role, qualifications, relevant experience and scope of responsibility.Typical gapThe report says 'competent person' without identifying who made the decision.Escalate whenNo accountable technical decision-maker can be identified.Source basisAS/NZS 3788:2024 competent-person decision framework.Match competence to the equipment, service, damage mechanism and decision being made.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forExperience record covering relevant pressure equipment, materials, damage and inspection method.Typical gapGeneral mechanical experience is assumed to cover specialist damage or repair assessment.Escalate whenThe decision involves unfamiliar cracking, high-temperature damage, complex repair or re-rating.Source basisAS/NZS 3788:2024 competence requirements throughout inspection and remediation.Confirm NDT personnel and methods have the required qualifications/procedures for the examination performed.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forPersonnel certification, written technique/procedure, equipment calibration and report.Typical gapA UT thickness sheet has readings but no probe, calibration, grid or technician traceability.Escalate whenCritical acceptance depends on untraceable or unsuitable examination data.Source basisAS/NZS 3788 NDE requirements and method-specific standards.For repairs or alterations, identify the competent people responsible for design, welding/material decisions, inspection and final acceptance.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forRepair specification, hold-point sign-offs and return-to-service verification.Typical gapThe fabricator, inspector and final acceptor roles are blurred.Escalate whenNo competent person verifies the work against the repair specification before return to service.Source basisAS/NZS 3788:2024 repair/remediation and final verification provisions.04
4. Check the external examination
External inspection should cover the complete accessible condition and the features that can reveal deterioration, overpressure, leakage, support problems or safeguarding defects.
Examine shell, heads, nozzles, flanges, closures and visible pressure-boundary surfaces for leakage, corrosion, cracking, bulging and distortion.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forLocation-tagged photographs and defect measurements.Typical gapReport says 'visual satisfactory' with no indication of which surfaces were accessible.Escalate whenActive leakage, bulging, crack-like indications or severe local corrosion are found.Source basisAS/NZS 3788:2024 external visual examination framework.Inspect supports, saddles, skirts, lugs, attachments, insulation interfaces and local load-transfer areas.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forPhotos of support contact points, welds, anchorages and corrosion traps.Typical gapPressure boundary looks sound but a corroded saddle or attachment is ignored.Escalate whenSupport deterioration could change loads or stability.Source basisAS/NZS 3788 external examination and structural attachment checks.Inspect connected piping, valves and local loads that may affect the vessel.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forNozzle/piping photos, support condition and evidence of misalignment or vibration.Typical gapA leaking or unsupported branch imposes load on the vessel nozzle but sits outside the inspection scope.Escalate whenDistortion, high vibration or nozzle load concerns are visible.Source basisAS/NZS 3788 external examination of associated pressure components and interfaces.Where corrosion or abrasion is visible, measure wall thickness at the affected locations rather than relying on visual judgement alone.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forTargeted UT map linked to exact locations and visual damage.Typical gapThe standard grid misses the visibly damaged area.Escalate whenLocal minimum thickness or extent cannot be established.Source basisAS/NZS 3788 condition-based thickness examination.05
5. Check the internal or equivalent examination
Internal examination should be planned around the actual service and damage mechanisms. Where entry is not used, the alternative method needs a defensible basis and coverage.
Confirm the internal examination scope covers expected corrosion, erosion, cracking, deposits and high-risk zones.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forInspection plan with sketches/locations and selected methods.Typical gapInspector enters the vessel but only records general condition photographs.Escalate whenKnown susceptible zones are inaccessible or omitted.Source basisAS/NZS 3788 internal examination and damage-mechanism planning.Record surface condition and cleaning adequacy before examination.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forPre-inspection cleaning record and as-inspected photographs.Typical gapScale or deposits hide the pressure boundary but the examination is still marked complete.Escalate whenThe surface condition prevents reliable inspection.Source basisAS/NZS 3788 examination preparation and method suitability.Where internal entry is replaced by an alternative/on-stream method, document why the method provides suitable coverage and sensitivity.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forCompetent-person plan, technique, coverage drawing and limitations.Typical gapA few external UT points are called an 'internal inspection equivalent' without technical justification.Escalate whenThe alternative method cannot detect the credible damage mechanism.Source basisAS/NZS 3788 alternative inspection and competent-person decision framework.Inspect internal attachments, welds, drains, low points, liquid/vapour interfaces and other service-specific hotspots.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forTagged photographs and examination results by location.Typical gapOnly shell plate is checked; internal supports and crevices are ignored.Escalate whenCrack-like indications or severe localised attack are detected.Source basisAS/NZS 3788 damage-mechanism and location-based examination.06
6. Check thickness data, corrosion rate and remaining life
Thickness numbers become useful only when they are traceable to location, comparable over time and judged against a verified minimum.
Link every thickness reading to a repeatable physical location and measurement method.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forUT grid/map, datum points, probe details and calibrated report.Typical gapA spreadsheet contains values but no one can find the same points next inspection.Escalate whenTrend data cannot be compared reliably.Source basisAS/NZS 3788 thickness-monitoring and integrity-assessment principles.Compare current minimum measured wall with the verified minimum required thickness or accepted assessment basis.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forCalculation/report showing minimum required wall and location-specific measured minimum.Typical gapAverage thickness is reported even though one local reading governs.Escalate whenMeasured wall is at or below the verified minimum.Source basisAS 1210 verified design basis and AS/NZS 3788 remaining-life assessment.Calculate corrosion/erosion rate only where the data sets are comparable and the mechanism supports trending.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forAt least two traceable measurement campaigns with dates, same locations/method and rate calculation.Typical gapReadings from different locations are subtracted to create a false corrosion rate.Escalate whenRate is accelerating, highly variable or dominated by localised attack.Source basisAS/NZS 3788 integrity assessment using inspection history and deterioration rate.Document remaining-life and next-inspection decisions with assumptions and limitations.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forCompetent-person calculation/report including minimum wall, rate, uncertainty and next due date.Typical gapA corrosion rate is calculated but never translated into a controlled inspection interval.Escalate whenRemaining life is short, uncertain or sensitive to an assumption.Source basisAS/NZS 3788 remaining-life and inspection-interval framework.07
7. Check pressure-relief and safeguarding devices
The vessel wall and the protective devices form one integrity system. Their inspection histories should be traceable separately.
Identify each pressure-relief device and match it to the protected equipment and design basis.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forP&ID, valve register, tag/serial, set pressure and service.Typical gapA relief valve certificate exists but cannot be matched confidently to the vessel.Escalate whenSet pressure or protected equipment relationship is uncertain.Source basisAS 1210 pressure protection and AS/NZS 3788 relief-device inspection framework.Check test/inspection interval, last test, next due date and seal/tag information.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forBench/in-situ test report, tag and valve history.Typical gapThe vessel is in date but the relief device has a separate overdue cycle.Escalate whenDevice is overdue, tampered with or has unexplained set-pressure change.Source basisAS/NZS 3788 pressure-relief device inspection/testing provisions.Inspect isolation valves, discharge piping and installation conditions that could prevent the protective device working as intended.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forField photos, valve position/locking and discharge route.Typical gapThe relief valve itself passed bench test but is isolated or discharges through a blocked/corroded line.Escalate whenThe protective path can be blocked or creates a new hazard.Source basisAS/NZS 3788 safeguarding-device installation and service checks.Check critical pressure/temperature controls and interlocks have defined inspection/test intervals and records.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forDevice list, functional/calibration tests and next due dates.Typical gapOnly the relief valve is managed; shutdown controls that prevent overpressure are absent from the inspection plan.Escalate whenA critical safeguard cannot be demonstrated to function.Source basisAS/NZS 3788 controls critical for safeguarding equipment.08
8. Check the lifecycle documentation package
The compliance package should let a future inspector reconstruct design, manufacture, inspection, repair and current integrity without relying on tribal knowledge.
Design package includes controlled calculations with the applicable design basis and clause/requirement references used by the engineer.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forVerified design report, calculations, drawings and revision history.Typical gapOnly a vessel drawing survives; the calculation basis and assumptions are missing.Escalate whenCurrent integrity decisions depend on design information that cannot be verified.Source basisAS 1210 design documentation and AS/NZS 3788 lifecycle record needs.Manufacturing package includes material certificates and pressure-boundary traceability.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forMaterial test certificates, heat maps/traceability and fabrication records.Typical gapMaterial grade is assumed from a drawing with no traceable certificate for critical replacements.Escalate whenUnknown material affects allowable stress, welding or damage assessment.Source basisAS 1210 manufacturing quality records.Welding package includes approved procedures/qualifications and welder traceability where applicable.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forWPS/PQR, welder qualification and weld map.Typical gapA repair invoice says 'weld repaired' with no procedure or welder record.Escalate whenPressure-boundary welding cannot be verified.Source basisAS 1210/AS 3992 manufacturing and AS/NZS 3788 repair requirements.Inspection/NDE package includes method, coverage, personnel, results, indications and acceptance decision.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forNDE reports, maps and competent-person disposition.Typical gapReport says 'NDT passed' without coverage or indication detail.Escalate whenCritical areas or repairs lack traceable examination evidence.Source basisAS/NZS 3788 examination and repair documentation provisions.Test and commissioning package includes pressure/leak/function test certificates and current operating limits.
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forTest certificate, calibrated instruments and authorised return-to-service record.Typical gapA pressure test certificate exists but test pressure, hold time or instrument traceability is unclear.Escalate whenThe item returned to service without the required test/verification evidence.Source basisAS 1210 testing and AS/NZS 3788 remediation/return-to-service documentation.Repairs, modifications, alterations, re-ratings and relocations are separately identified and fully closed out.Escalation-sensitive
Add measurement, evidence or notes
Inspection guidance and source basis
Evidence to look forInitial inspection, work specification, progress/hold-point certification, NDE, competent-person names and final verification.Typical gapA repair disappears into maintenance history and the future inspector cannot tell what changed.Escalate whenChange may have increased risk or altered the verified design basis without the required review.Source basisAS/NZS 3788:2024 repair, modification, alteration, re-rating and relocation framework.Overall notes
Record the final screening context
Note operating restrictions, missing documents, work orders, competent-person decisions or assumptions that affect the result.
Minimum useful attachment pack
The checklist is most useful when the evidence can travel with the request.
Five questions before you call it complete
1Can every inspection date be traced to a documented interval basis rather than a generic calendar?
2Can the person accepting the equipment show why they are competent for this equipment, damage mechanism and decision?
3Can current thickness readings be compared to both the same locations historically and a verified minimum wall?
4Are relief devices and other critical safeguards managed as separate traceable inspection items?
5Could a future inspector reconstruct every pressure-boundary repair or change from the records alone?
Common gaps and weak evidence
The register has one inspection date, hiding separate external, internal, relief-device and control-test obligations.
Hundreds of thickness readings exist, but there is no verified minimum wall, corrosion-rate logic or remaining-life decision.
A job title is recorded, but no evidence shows relevant knowledge of the equipment, service, damage mechanism or decision.
Pressure-boundary work is invoiced and closed without a traceable engineering specification, NDE pack and final verification.