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Specialist Integrity Service

CUI Integrity Management
Corrosion Under Insulation

End-to-end Corrosion Under Insulation integrity management — from insulated asset registers and risk screening through advanced NDT inspection planning, field verification, and program documentation aligned with API RP 583.

CUI is one of the most persistent and difficult-to-detect degradation mechanisms affecting insulated piping, pressure vessels, and process equipment. TES Canada approaches CUI as an asset integrity management challenge — not simply an inspection activity. Our programs combine risk-based prioritization, location-driven inspection strategy, advanced NDT, engineering assessment, and practical data management to create a defensible, sustainable CUI integrity management program.

The Challenge

Why Spot Inspection Is Not Enough

CUI is hidden beneath insulation, may be highly localized, and is rarely distributed uniformly along a system. A technically defensible CUI program must answer four engineering questions: Where is CUI most likely to occur? Where would failure have the greatest consequence? Which inspection method is suitable for the expected damage and geometry? How should findings translate into repair, mitigation, FFS, or future inspection decisions?

Random insulation removal without risk-based prioritization consistently misses the most damaged locations while consuming inspection resources at lower-risk areas. A structured CUI program changes this.

CUI is hidden — damage is not visible until penetration or leakage occurs
Damage concentrates at predictable locations — supports, terminations, penetrations, low points
Temperature bands alone do not identify where within a system damage will occur
Thermal cycling can create aggressive wet-dry salt concentration conditions
Moisture ingress points and insulation condition drive probability of CUI
Random insulation removal consistently misses the highest-risk locations
Advanced NDT can screen large areas without full insulation removal when properly selected
Findings must be connected to risk ranking, repair, and future inspection decisions
Service Capabilities

CUI Integrity Management — What TES Canada Delivers

CUI Susceptibility Assessment & Risk Ranking

  • Insulated asset register development
  • Operating temperature and CUI susceptibility screening
  • Location-driven risk assessment — supports, terminations, penetrations
  • Thermal cycling and moisture ingress evaluation
  • Risk ranking by probability and consequence of failure
  • Alignment with API RP 583 susceptibility criteria

Inspection Planning & Advanced NDT Integration

  • Location-driven inspection scope development
  • Digital Radiography (DR/CR) for CUI profiling
  • Pulsed Eddy Current (PEC) screening strategy
  • Long-Range UT (LRUT) for pipe rack and difficult-access sections
  • Neutron backscatter and thermography integration
  • Direct examination and insulation removal planning

CUI Data Management & Program Documentation

  • Inspection finding data structuring and trending
  • Corrosion rate assessment and remaining life evaluation
  • Risk model evergreening from inspection results
  • CUI integrity manual development
  • Digital risk reassessment tool support
  • Connection to RBI, FFS, and repair planning

Engineering Assessment & Mitigation

  • FFS assessment of CUI wall loss findings
  • Insulation system condition assessment
  • Moisture control and water ingress mitigation planning
  • Coating selection and reinstatement guidance
  • Repair prioritization and action tracking
  • Chloride SCC evaluation for stainless steel systems
Standards & Frameworks

Aligned with Recognized CUI and Inspection Standards

API RP 583Corrosion Under Insulation and Fireproofing
API 571Damage Mechanisms — CUI and External Corrosion
NACE/AMPP SP0198Control of Corrosion Under Thermal Insulation
API RP 580 / API RP 581Risk-Based Inspection
API 579-1/ASME FFS-1Fitness-for-Service
HSE GuidanceCUI and External Chloride SCC in Stainless Steels
Related Services

Connected TES Canada Services

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Discuss Your CUI Integrity Program

Whether you are starting a new CUI program, improving an existing one, or need engineering assessment of CUI findings, TES Canada can help develop a practical, risk-informed approach.

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