Jacket

A jacket is the steel tubular space-frame substructure of a fixed offshore platform, founded on piles and supporting the topsides above the waterline, inspected for fatigue cracking at nodes, marine growth, and CP performance.

Definition

Jacket inspection uses ROV-deployed UT, ACFM, MPI/Mag, and visual methods on the underwater portions, focused on fatigue-critical tubular joints where stress concentrations occur. Cathodic protection potential surveys verify corrosion control.

Related terms

  • FPSO (Floating Production, Storage and Offloading) — An FPSO is a ship-shaped floating offshore facility that receives produced hydrocarbons from subsea wells, separates and treats them, stores the oil in its hull, and offloads to shuttle tankers — inspected to a combination of marine-class (DNV, ABS), API, and
  • Riser — A riser is the pipe segment that conveys produced hydrocarbons from the seabed to a surface facility (platform or FPSO), subject to dynamic loading, corrosion, and fatigue, inspected by ROV-deployed UT, ACFM, and visual methods.
  • Topsides — Topsides are the surface modules of an offshore facility (platform or FPSO) above the splash zone — including process equipment, utilities, accommodation, and helideck — inspected per API 510/570/653 with the additional challenges of offshore logistics and mar
  • Alternating Current Field Measurement (ACFM) — ACFM is an electromagnetic NDT technique that induces a uniform AC field in a conductive component and measures the field disturbance over surface-breaking cracks to size their length and depth without surface cleaning.

Further reading

offshore platform inspection subsea ndt challenges

More asset-type terms

Pressure Vessel · Storage Tank · Heat Exchanger · Fired Heater · Pipeline · Wellhead · Christmas Tree · Blow-Out Preventer · Valve · Flange

Where this comes up in practice

Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.

Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.