Pressure Vessel Repairs: Planning Through Return to Service
A pressure vessel repair is a controlled technical change, not just a maintenance task. The work needs a defensible repair basis, competent resources and verification that addresses the original defect and the completed repair. Planning should start before material is removed or evidence is lost.
Characterise the condition before defining the repair
Identify the asset and the exact affected area, preserve photographs and examination results, and record the operating context. A visible symptom may not show the full extent or cause of damage. Additional examination or engineering assessment may be needed before the repair boundary can be defined.
Record any immediate restrictions or unresolved technical questions through the site’s responsible personnel. The decision to continue operating while planning work requires its own basis; the intention to repair later is not that basis.
Plan pressure vessel repairs from the defect evidence through engineered scope and post-repair verification.
Establish the engineered scope and controls
The repair plan should define the approved scope, technical requirements and responsibilities for review and sign-off. It may involve weld repair, component replacement or modification, but the appropriate solution depends on the evidence and equipment. This guide does not give welding or repair execution instructions.
Agree material traceability, required procedures and competent personnel, inspection stages and witness requirements with the responsible engineering and repair team. Clarify how an unexpected condition will be handled without an uncontrolled expansion of scope.
- Defect location, extent and examination evidence.
- Approved repair scope and controlled revisions.
- Material and workmanship evidence required by the plan.
- Hold points and responsibilities for technical decisions.
- Post-repair examination and close-out deliverables.
Verify the completed work against its basis
Post-repair examination should be selected for the work performed and the original damage question. Testing and NDT are not interchangeable, and a pressure test should not be assumed to replace all required examination.
If a test or examination finds an issue, record the disposition and any repeated work. Keep the final evidence linked to the actual repair location and configuration. A general contractor completion note is not a substitute for the technical records defined by the repair plan.
Control the return to service
Confirm that hold points are closed, outstanding recommendations are assigned and any revised limits are communicated to operations. Update drawings, asset records and future inspection plans as necessary. Registration or verification implications should be reviewed for the actual change and jurisdiction rather than assumed away because the vessel was previously in service.