Specialist · 12 checks

Offshore / Marine
QA inspection checklist

Offshore and marine construction quality audit — PFEER, LOLER, and marine standards.

Every check below carries what good looks like, when it passes, the standard it comes from and the defects that usually fail it. That guidance is what turns a tick-box into an inspection.

Structural

  1. 1.
    Steel fabrication to offshore specification
    What to look forSteel grade per design (typically S355 J2+N / S420N for offshore primary, with through-thickness Z-quality where required). Mill certificates EN 10204 Type 3.2 (third-party). Charpy impact testing values per design temperature (typically -40°C).
    Acceptable whenPer DNV-OS-C401 / ISO 19902 / NORSOK N-004: steel grade per design, Z-quality (Z25/Z35) for through-thickness loading, Charpy impact 27 J at design temperature. Type 3.2 inspection certificate with NDT.
    StandardDNVGL-OS-C401 — Fabrication and testing of offshore structures. ISO 19902:2020 — Fixed steel offshore structures. NORSOK M-101 — Structural steel fabrication.
    Common defectsWrong grade (S275 vs S355) — non-compliantNo Z-quality where through-thickness loadingCharpy values not at design temperatureType 3.1 cert supplied where 3.2 requiredLamellar tearing not screened
  2. 2.
    Welds NDT tested to required standard
    What to look forNDT per project NDT plan — typically 100% UT (or RT) on primary butt welds, 100% MPI / DPI on T-K-Y joints. Operator PCN / ASNT Level II/III. Acceptance per DNV / NORSOK / ISO.
    Acceptable whenPer DNV-OS-C401 / ISO 19902 / NORSOK M-101: NDT coverage 100% on primary structure butt welds and T-K-Y joints; acceptance criteria per relevant standard. PCN / ASNT operators.
    StandardDNVGL-OS-C401. ISO 19902:2020. NORSOK M-101. BS EN ISO 5817 (acceptance levels).
    Common defectsNDT coverage below project planOperator not PCN / ASNT certifiedDefects identified but not repaired / re-shotUT operator using miscalibrated probeNo traceability between weld number and NDT report
  3. 3.
    Corrosion protection system applied correctly
    What to look forCoating system per NORSOK M-501 — typically zinc primer + epoxy + polyurethane topcoat. Surface preparation Sa 2.5 minimum. DFT meeting spec at all areas. Stripe coating at edges. Holiday testing on submerged.
    Acceptable whenPer NORSOK M-501: surface prep ISO 8501-1 Sa 2.5 / 3; profile per coating ETA; DFT per coat per spec (typically 250-450 µm total system above splash zone, 600+ submerged). Stripe coats and holiday testing on submerged.
    StandardNORSOK M-501:2022 — Surface preparation and protective coating. ISO 12944 (corrosion protection). ISO 8501-1 / 8503 (surface preparation).
    Common defectsDFT below spec at edges (Faraday)No stripe coat — early failure at sharp edgesSurface preparation Sa 2 instead of 2.5Topcoat applied outside re-coat windowHoliday testing not performed on submerged
  4. 4.
    Cathodic protection installed (if required)
    What to look forSacrificial anodes (zinc / aluminium / Al-Zn-In alloy) installed per CP design. Quantity, weight, and distribution to give correct current density. Anode connection welded directly to structure (not bolted). Reference cells installed.
    Acceptable whenPer DNV-RP-B401 / NORSOK M-503: anode mass per design lifetime; -800 mV vs Ag/AgCl protection potential typical; current density per zone. Reference cells for monitoring.
    StandardDNV-RP-B401:2021 — Cathodic protection design. NORSOK M-503:2021. ISO 15589-2 (offshore CP).
    Common defectsAnode mass below design — protection lifetime shortBolted connection — high resistance, no protectionAnodes shielded by adjacent structureNo reference cellsWrong alloy for environment

Mechanical & Piping

  1. 5.
    Pipework pressure tested to offshore spec
    Record: Test pressure (bar)
    What to look forHydrostatic test at 1.5× design pressure for offshore process piping per ASME B31.3 / NORSOK L-002. Hold ≥ 1 hour. Test fluid per chemical compatibility. Records retained with NDT and material certs.
    Acceptable whenPer ASME B31.3 / NORSOK L-002: test 1.5× design (or per code); minimum hold 1 hour; no leaks. Pneumatic test only with safety case for offshore due to compressible energy hazard.
    StandardASME B31.3 — Process piping. NORSOK L-002 — Piping design, layout and stress analysis. NORSOK L-001 — Piping and valves.
    Common defectsPressure drop > permittedPneumatic test on long pipe — explosion energy too highTest fluid contaminatedHold time short of 1 hourNo record of test
  2. 6.
    HVAC systems salt-air rated
    What to look forHVAC components in offshore environment — fans, dampers, coils, ducting — selected for marine atmosphere. Stainless or hot-dip galvanised metal. Coil fins coated. Filter banks include salt-removal stage.
    Acceptable whenPer NORSOK H-001 — HVAC offshore: components rated for offshore corrosion class CX / C5-M (ISO 12944-2). Salt-removal filtration. Fans IP56+ where appropriate. Drainage of condensate to safe location.
    StandardNORSOK H-001:2018 — HVAC systems. ISO 12944-2 — Corrosion classes.
    Common defectsPainted mild steel ducting — corrodes within 3 yearsFan motors not IP56 — salt ingressNo salt filter — corrosion of internal componentsCoil fins uncoated — chloride attackDrains terminate in fire compartment
  3. 7.
    Crane and lifting equipment LOLER compliant
    What to look forAll lifting equipment — pedestal cranes, monorails, davits, padeyes — has thorough examination certificate per LOLER. Visible SWL / WLL marking. Loose lifting gear (slings, shackles) LOLER tagged and in date.
    Acceptable whenPer LOLER 1998 / DNV 2.7-1 (offshore container) / DNV-ST-N001 (lifting): thorough examination at 6-month intervals (passenger lift) or 12 months (other); SWL marked; certificates current.
    StandardLOLER 1998 (Lifting Operations and Lifting Equipment Regulations). DNV 2.7-1 — Offshore containers. DNV-ST-N001 — Marine operations and marine warranty.
    Common defectsCrane thorough examination overdueNo SWL markingLoose lifting gear without LOLER tagCertificate covers different equipmentCrane modified without re-certification

Safety Systems

  1. 8.
    Fire and gas detection systems tested
    What to look forFire and Gas (F&G) detectors (smoke, heat, flame, hydrocarbon, toxic) installed per detector layout. Each detector tested with test gas / smoke source. Voting logic (1oo2, 2oo3) per design. Loop integrity tested.
    Acceptable whenPer IEC 61511 / NORSOK S-001: F&G detection per safety function spec; SIL rating per Process Hazard Analysis; voting logic per F&G philosophy. 100% functional test at commissioning.
    StandardIEC 61511:2016 — Functional safety. NORSOK S-001:2018 — Technical safety. NORSOK Z-013 (risk and emergency).
    Common defectsDetectors in shadow zone — no coverageVoting logic wrong — false alarm or no detectionNot all detectors testedTest gas different from process gas — false negativeSIL rating not verified
  2. 9.
    Emergency shutdown (ESD) system tested
    What to look forESD system tested end-to-end — initiator (push-button, F&G output) shuts down designed equipment within design time. Cause-and-effect matrix verified. SIL achievement verified.
    Acceptable whenPer IEC 61511 / NORSOK S-001: ESD function tested per cause-and-effect matrix; shutdown within designed time; SIL rating verified (typically SIL 2 / SIL 3).
    StandardIEC 61511:2016. NORSOK S-001:2018. NORSOK I-002 — Safety systems.
    Common defectsESD did not actuate equipment as per matrixShutdown time exceeds designSIL achievement not verifiedCause-and-effect matrix not test-provenBypass left in test mode
  3. 10.
    Lifeboat/life raft inspected and in date
    What to look forLifeboats and life rafts within service interval (typically 12-month service). Hooks load-tested. Quick-release certified. Davits LOLER. Team muster station signs and routes clear.
    Acceptable whenPer SOLAS / MCA Marine Guidance Note: lifeboat service annual; hooks 5-yearly load test; davits LOLER 6-monthly. Service certificate from approved provider.
    StandardSOLAS Chapter III. UK Marine Guidance Notes (MGN). LSA Code (Life Saving Appliances).
    Common defectsLifeboat overdue serviceHook load test missingDavits not LOLER testedMuster station signs covered or missingLights / batteries not tested
  4. 11.
    Helideck condition and markings correct
    What to look forHelideck markings (touchdown circle, identifier, "H", obstacle markers) per CAA CAP 437. Surface texture provides friction. No loose objects, water ponding, or surface defects. Helideck friction certified.
    Acceptable whenPer CAA CAP 437:2024 — Standards for offshore helicopter landing areas: markings, lighting, friction, surface condition per spec; D-value, t-value markings; obstacle limitation surfaces clear.
    StandardCAA CAP 437:2024 — Offshore helicopter landing areas. UK Civil Aviation Authority. ICAO Annex 14.
    Common defectsMarkings faded — wrong identifierFriction below spec — slippery for landingLoose objects — FOD ingestion riskObstacles in safety net zoneLighting inoperative — night ops affected
  5. 12.
    PFEER assessment current
    What to look forPrevention of Fire and Explosion, and Emergency Response (PFEER) regulations assessment current and reviewed. Findings closed out. ALARP demonstration. Performance Standards in place. Drills and exercises records.
    Acceptable whenPer Offshore Installations (Prevention of Fire and Explosion, and Emergency Response) Regulations 1995 (PFEER) / Safety Case Regulations 2015: PFEER assessment current; PSs documented; drills per regs; OIM responsible.
    StandardPFEER Regulations 1995. Offshore Installations (Safety Case) Regulations 2015. HSE Offshore.
    Common defectsPFEER assessment overdueFindings open beyond agreed datesNo ALARP demonstrationPerformance Standards not measuredDrill / exercise records incomplete

Questions people ask

What is a offshore / marine QA inspection for?

To record that the work was checked against the specification before it was covered up or handed over: a pass or fail against each item, a measurement where one matters, and a photo where it failed. It is the evidence a client's quantity surveyor or clerk of works asks for, and the thing that settles the argument at final account.

What standards does this checklist check against?

Each item names its reference. On this checklist that includes DNVGL-OS-C401, DNVGL-OS-C401. ISO 19902:2020. NORSOK M-101. BS EN ISO 5817 (acceptance levels)., NORSOK M-501:2022, DNV-RP-B401:2021, ASME B31.3, NORSOK H-001:2018. The contract specification and the approved drawings always take precedence over a general standard; where they say something stricter, inspect to that.

Who signs a QA inspection off?

The person who carried out the check, named and dated, and where the contract calls for it the client's representative as a witness. The signature records that the check was done and what was found. It is not a warranty of the work.

How many items are on it, and do I have to use them all?

12 checks across 3 sections. Delete what does not apply to the job and add anything the specification asks for that is not here. A checklist that has plainly been thought about carries more weight than a long one nobody read.

Is this useful for a subcontractor as well as a main contractor?

More so. The subcontractor is the one who gets asked to come back and open something up. A signed inspection sheet with photos at the time is the cheapest insurance on a construction site.

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