Back to All Inspection Scopes
Refinery Process Piping & Chemical Plants
Refinery Process Piping & Chemical Plants

Corrosion Under Insulation (CUI) Screening Inspection Scope

Turnkey NDT Solution for Insulated Piping, Process Vessels & Column Skirts

Primary NDT Techniques:PECRTRGWT

Targeted Damage Mechanisms

  • Corrosion Under Insulation (CUI)
  • External Chloride Stress Corrosion Cracking (ECSCC)
  • Atmospheric Rusting

Key Inspection Challenges Resolved

  • Insulation removal costs can exceed 80% of total maintenance budget.
  • Traditional visual inspection requires scaffolding and thermal insulation stripping.
  • Severe CUI can cause catastrophic pinhole leaks and sudden hydrocarbon releases.

Standard Field Inspection Workflow

1

Risk-Based CUI Mapping

Review API 570 circuit records and thermal camera imagery to prioritize CUI-susceptible operating temp zones (30°F to 300°F / -4°C to 150°C).

2

Guided Wave (GWT) Screening

Attach magnetostrictive GWT ring to screen long straight piping runs (up to 50 meters in both directions) from a single transducer location.

3

Pulsed Eddy Current (PEC) Grid Sizing

Perform high-density PEC grid scan over elbows, tees, nozzle connections, and pipe support shoes to map remaining wall thickness.

4

Verification & Direct Repair

Use Real-Time Radiography (RTR) or targeted insulation window cuts for UT validation on locations showing >25% wall loss.

Recommended Hardware & Probes

  • Eddyfi Lyft PEC System
  • Guided Ultrasonics Wavemaker G4
  • OpenVision Real-Time X-Ray

Governing Inspection Standards

  • API 570 Piping Inspection Code
  • NACE/AMPP SP0198 Control of CUI
  • ISO 20669 PEC Testing
Ready to Execute This Scope?

Post Scope for Bids or Hire Certified NDT Agency