Preparation is what separates a productive inspection from an expensive delay. An inspector who arrives at a vessel that is dirty, improperly permitted, or missing its previous records cannot do the work, and the day rate runs regardless. This guide covers what operations and integrity teams need to have in place before the inspector arrives. For a breakdown of what inspectors look for once they are on site, see our full inspection checklist.
What follows is practical advice from a working inspector's perspective, not a bureaucratic pre-inspection questionnaire, but the things that actually make or break a scheduled inspection day.
Why Preparation Matters
A well-prepared inspection runs faster, produces better records, and reduces the chance of a follow-up visit to complete scope that couldn't be done on the first day. In practical terms: if the vessel isn't gas-free when the inspector arrives, the day is lost. If CML locations haven't been identified, the inspector has to develop them from scratch, adding hours. If the previous inspection report isn't available, corrosion rate calculations are impossible and the remaining life estimate is based on nominal thickness, not actual corrosion history. All of these are preventable.
The inspection cost is fixed whether or not the inspection proceeds efficiently. Preparation is the most cost-effective thing an operator can do to get full value from a scheduled inspection.
Pre-Inspection Documentation to Gather
Send these documents to the inspector before the inspection date, not on the morning of. Having them in advance allows the inspector to review service history, identify areas of concern, and plan the scope before arriving on site.
- ▸Previous inspection reports: The last two to three inspection cycles minimum. A single previous report gives one corrosion rate data point. Two or three cycles allow trend analysis, whether corrosion is accelerating, stable, or decelerating. If only one previous report exists, bring it. If none exist, flag that clearly when booking the inspection.
- ▸ASME nameplate data or design data sheet: MAWP, design temperature, shell and head material specification, and original corrosion allowance. The ASME nameplate on the vessel provides most of this if the data sheet is not available.
- ▸ABSA registration certificate: For Alberta vessels, the ABSA registration certificate confirms the vessel is properly registered as required under the Pressure Equipment Safety Regulation. If the certificate cannot be located, contact ABSA before the inspection to confirm registration status.
- ▸P&ID showing vessel number and connections: Current as-built P&ID showing all nozzle connections, connected process streams, and service conditions. The inspector uses this to assess the damage mechanism exposure at each nozzle and connection.
- ▸Current operating parameters vs. design: If the vessel is operating at conditions meaningfully different from its design conditions (lower pressure, different temperature range, different process fluid than originally specified), document the actual operating envelope. This affects the fitness-for-service assessment.
- ▸Repair history and weld maps: Any weld repairs, liner installations, overlay cladding, or alterations made since original construction. Repaired areas need to be disclosed and are examined specifically during the inspection.
- ▸NDE records from previous inspections: UT grid maps, PT/MT reports, RT films or digital records from prior turnarounds. These are the baseline against which new NDE findings are compared.
- ▸CML location drawings or sketches: Drawings showing where corrosion monitoring locations (CMLs) are positioned on the vessel, including which shell course, which head, and what elevation. If CMLs are not formally documented, describe how previous UT readings were taken so the inspector can replicate positions.
- ▸PRV test records: Documentation of the last bench test for all pressure relief devices on the vessel. Out-of-interval PRVs are flagged in the inspection report and may require action before the vessel is returned to service.
Vessel Preparation for Internal Inspection
This is where most inspection delays originate. Vessel preparation for confined space entry is the operator's responsibility. The inspector enters as an entrant under a permit the operator prepares; the inspector does not issue permits or certify the vessel as safe for entry.
- ▸De-inventory and depressurize: Vessel is fully drained and depressurized. All process connections are blinded, not just valved off. Valve isolation alone does not constitute safe isolation for confined space entry on regulated pressure equipment.
- ▸Purge and gas-free certificate: The vessel has been purged with nitrogen or air to displace process gas, and a competent person has issued a gas-free certificate confirming the atmosphere is safe for entry. The certificate must be in hand before the inspector enters the vessel. If the gas-free certificate is not ready, the inspection cannot start.
- ▸Confined space entry permit: A completed confined space entry permit posted at the manway, with an attendant stationed outside during entry. This is a legal requirement under Alberta OHS legislation. The inspector's entry is covered by this permit.
- ▸Internal cleaning: Scale, sludge, sediment, and residue removed from internal surfaces. This cannot be emphasized enough: an inspector cannot perform meaningful visual examination on a vessel whose surfaces are covered in sludge or scale. Cleaning needs to expose the metal surface. Pressure washing and vacuum truck removal of accumulated solids, not just flushing, is what is needed for a dirty vessel.
- ▸Access equipment: Scaffolding, man-riding equipment, or a manway stand arranged and in place. The inspector should not be expected to coordinate access equipment logistics on the inspection day. It needs to be ready before mobilization.
- ▸Lighting: Adequate portable lighting arranged inside the vessel. In hazardous area classifications, explosion-proof lighting is required. Adequate means enough to actually see the surfaces being inspected. A single work light is not sufficient for a large separator or column.
Site Access and Safety Logistics
Administrative and safety logistics that are often overlooked until the inspector is already on site waiting:
- ▸Safety induction: If the site requires a site-specific safety induction, confirm whether the inspector needs to complete it on arrival or whether it can be pre-completed online. Some site inductions take 1 to 2 hours. Schedule inspection day timing accordingly.
- ▸PPE requirements: Communicate any site-specific PPE requirements to the inspector in advance: H2S monitor requirements, specialized respiratory protection, FR clothing, metatarsal boots, fall protection requirements for elevated work. The inspector brings standard PPE but may need to source site-specific items if not communicated ahead of time.
- ▸ABSA requirements confirmation: For regulated Alberta pressure equipment, confirm whether the inspection scope includes any ABSA-reportable findings or alterations that require specific notification. If the previous inspection flagged items that required ABSA notification, confirm those were addressed.
- ▸Gate access and escort: For remote or controlled-access sites, confirm gate access credentials and whether an escort is required. Delays at the gate consume billable time.
What to Have at Hand During the Inspection
Even after thorough pre-inspection preparation, a few things need to be physically present on the day:
- ▸Previous inspection report, printed or on tablet: The inspector will reference specific CML readings from the previous inspection during measurement. Having a printed copy or accessible digital copy speeds up the comparison process.
- ▸CML location drawings or sketches: The inspector takes UT readings at defined CML positions. If CML drawings are not prepared, the inspector works from descriptions in the previous report, which adds time and introduces positioning variability.
- ▸Operations contact for service condition questions: Have someone accessible who can answer questions about current service conditions: actual operating temperature, actual fluid composition, any recent upsets or process changes. These are relevant to damage mechanism assessment and may affect the inspection scope on the day.
Common Preparation Mistakes That Delay Inspections
These are the most frequent causes of inspection delays encountered in field practice:
| Mistake | Consequence |
|---|---|
| Vessel not fully gas-freed when inspector arrives | Inspection cannot start. Day rate continues. Rescheduling required. |
| No CML locations identified or documented | Inspector must develop CMLs from scratch based on damage mechanism assessment, adds 1 to 3 hours and means the first inspection becomes baseline only, with no corrosion rate calculation possible |
| No previous records available | Corrosion rate cannot be calculated. Only remaining life from nominal or nameplate thickness is possible, which defaults to a conservative inspection interval |
| Access equipment not arranged | Inspector cannot reach upper vessel heads, nozzles on elevated sections, or vessel internals requiring a stand, so scope is incomplete |
| Confined space permit not completed before inspector arrives | Entry cannot proceed. Permit preparation time delays start. Consider this a day-planning item, not a paperwork item. |
| Vessel interior not cleaned to bare metal | Pitting and surface corrosion cannot be assessed under scale. Inspector documents the limitation. Re-entry may be required after cleaning. |
| P&ID not current (showing decommissioned nozzles or missing new connections) | Damage mechanism assessment is based on incorrect service information. Always provide the current as-built P&ID, not the original design P&ID. |
What Happens After the Inspection
Understanding the post-inspection process helps operators plan for findings and return-to-service decisions.
- ▸Draft report timeline: Expect a draft inspection report within 5 to 10 business days of the inspection, depending on scope and whether NDE subcontractor reports need to be incorporated. Complex scopes with significant NDE follow-up take longer.
- ▸Report review process: The draft report is issued for client review before final sign-off. This is the time to clarify any findings, confirm equipment identification details, or flag any factual discrepancies. The inspector's professional conclusions and recommendations are not changed through review, but administrative details are confirmed.
- ▸Non-conformances and findings: Findings requiring repair or corrective action are listed in the report with a recommended action and, where applicable, a required-by date. Repairs to regulated Alberta pressure vessels under ASME Section VIII require ABSA notification and in some cases ABSA review before the vessel is returned to full service.
- ▸ABSA notification requirements: Significant findings, including cracks in pressure-retaining welds, identified hydrogen damage, metal loss exceeding the corrosion allowance, or any finding that requires an alteration repair, must be reported to ABSA before the vessel is returned to service. The inspection report will identify findings that trigger this requirement. Do not return the vessel to service on findings that require ABSA review without completing that process.
FAQs
How much notice should I give the inspector before a scheduled turnaround inspection?
Six to ten weeks is the recommended lead time for a turnaround internal inspection. This allows time to confirm scope, gather and transmit documentation in advance, coordinate NDE subcontractors if the inspection scope warrants it, and resolve any access or permitting questions before the inspection date. During peak turnaround seasons, spring and fall in Alberta, availability tightens, so earlier is better. For an on-stream external inspection with no confined space entry required, two to four weeks is usually sufficient.
What if the vessel is too dirty to inspect internally?
The inspection proceeds under limitations. The inspector documents that internal surfaces could not be adequately assessed due to fouling or scale accumulation, records UT measurements where surface contact is possible, and notes the scope limitation in the report. The report will typically call for re-entry after cleaning to complete the visual scope. This is a waste of mobilization cost that can be avoided entirely by ensuring the vessel is cleaned before the inspector arrives.
Can a partial inspection be done if access to part of the vessel is limited?
Yes, with scope limitations documented in the report. If a section of the vessel is inaccessible, for example, a lower head covered by a fixed internal packed bed that cannot be removed, or a nozzle that cannot be internally accessed, the inspection report identifies the limitation and typically calls for external NDE (UT mapping, PAUT) to provide some data for the inaccessible zone. The next inspection interval for the vessel as a whole is set conservatively when scope limitations exist.
What if previous CML records don't match current vessel condition, the positions have shifted or numbers don't correspond?
This is more common than it should be, especially when inspection records have been maintained by different parties over the years. The inspector reconciles the positions as best as possible based on the description in the previous report, takes readings at the best-matched locations, and documents the discrepancy. Going forward, a set of CML drawings is prepared as part of the current inspection to establish a definitive location reference for future inspections. The corrosion rate calculated from poorly matched positions carries more uncertainty and is treated accordingly in the remaining life calculation.
How long does the inspection report take, and when can I return the vessel to service?
The draft report is typically issued within 5 to 10 business days. For vessels with no significant findings, return to service can proceed after the inspection while the report is being prepared. The inspector will advise if any finding requires action before return to service. If a significant finding exists (crack, metal loss below minimum required thickness, PRV out of test interval), the inspector will communicate that clearly on the inspection day and the report will formalize the finding and required action. Do not assume a vessel with known significant findings can return to service just because the written report hasn't been issued yet.