Extensive 2-Day Masterclass: Corrosion Under Insulation (CUI)

Course Overview

This intensive 2-day CUI masterclass provides comprehensive knowledge of corrosion under insulation phenomena, inspection techniques, prevention strategies, and management programs. Designed for integrity engineers, inspection professionals, corrosion specialists, and maintenance managers across all industries where insulated equipment operates.

Target Audience: Integrity engineers, corrosion specialists, inspection professionals, maintenance managers, reliability engineers, plant engineers, NDT technicians, and asset management professionals in petrochemical, power generation, and manufacturing facilities.

Course Objectives:

• Understand CUI and CUI mechanisms and influencing factors

• Master inspection and detection techniques for CUI

• Implement effective prevention and mitigation strategies

• Develop comprehensive CUI management programs

• Apply risk-based inspection approaches to CUI

• Ensure regulatory compliance and industry best practices

Day 1: CUI Fundamentals, Mechanisms, and Inspection

Session 1: Introduction to CUI (8:00 AM - 10:00 AM)

Understanding CUI Phenomena

Foundation of corrosion under insulation:

CUI Definition and Scope:

• Corrosion occurring on external surfaces beneath insulation

• Hidden damage difficult to detect

• Major integrity threat across all industries

• Estimated costs: billions annually worldwide

• Statistics: 40-60% of piping maintenance costs

• Historical catastrophic failures and incidents

Types of CUI:

• Corrosion Under Insulation (CUI): general atmospheric corrosion

• Stress Corrosion Cracking Under Insulation (CUISCC)

• Microbiologically Influenced Corrosion (MIC)

• Chloride-induced pitting and SCC

• External corrosion on hot and cold systems

Susceptible Equipment:

• Carbon steel piping and vessels

• Stainless steel systems: 304, 316 grades

• Operating temperature range: -4°C to 175°C (critical zone)

• Cyclic operations and thermal cycling

• Equipment subject to weather exposure

• Deadlegs and infrequently used lines

Economic Impact:

• Maintenance and repair costs

• Production losses from shutdowns

• Safety incidents and environmental releases

• Insurance and liability costs

• Replacement versus repair decisions

• Industry statistics and benchmarks

Session 2: CUI Mechanisms and Contributing Factors (10:15 AM - 12:30 PM)

How CUI Occurs

Understanding corrosion mechanisms:

Water Ingress Pathways:

• Damaged or degraded insulation jacketing

• Penetrations and terminations: flanges, supports

• Improper sealing at equipment interfaces

• Missing or damaged vapor barriers

• Condensation from temperature cycling

• Rain, spray, and deluge system water

• Steam tracing leaks

Corrosion Chemistry:

• Atmospheric corrosion accelerated by insulation

• Electrolyte formation under insulation

• Oxygen availability and differential aeration

• Chloride contamination from insulation or environment

• pH changes from insulation leachates

• Temperature cycling effects on corrosion rates

Material Susceptibility:

• Carbon steel: general corrosion, thinning

• 300-series stainless steel: chloride SCC

• Low-alloy steels: hydrogen embrittlement risks

• Aluminum: caustic corrosion from certain insulations

• Copper alloys: stress corrosion cracking

Temperature Effects:

• Critical temperature range: -4°C to 175°C

• Maximum CUI activity: 50-150°C

• Condensation zone below dew point

• Thermal cycling acceleration

• Hot-cold interface areas

• Seasonal temperature variations

Insulation System Factors:

• Insulation material selection

• Jacketing material and condition

• Vapor barrier effectiveness

• Sealant and mastic quality

• Installation workmanship

• Maintenance and repair quality

• Age and service history

Session 3: Risk Assessment and Prioritization (1:30 PM - 3:30 PM)

Identifying High-Risk Areas

Implementing risk-based approaches:

Risk Factors:

• Operating temperature (susceptibility zone)

• Cyclic versus continuous operation

• Age of insulation system

• Geographic location and climate

• Insulation type and condition

• Damage history and repair records

• Material of construction

Likelihood Assessment:

• Inspection history and findings

• Previous corrosion damage

• Design and installation quality

• Operating conditions severity

• Maintenance practices

• Environmental exposure

• Age and service life

Consequence Evaluation:

• Safety hazards: flammable, toxic fluids

• Environmental impact potential

• Production criticality

• Replacement cost and complexity

• Accessibility for repair

• Redundancy availability

• Regulatory implications

Risk-Based Inspection (RBI):

• API 580/581 methodology application

• Damage mechanism identification

• Probability of failure calculations

• Consequence of failure assessment

• Risk matrix development

• Inspection prioritization

• Resource optimization

High-Risk Locations:

• Flanges, valves, and fittings

• Pipe supports and attachments

• Termination points at equipment

• Deadlegs and infrequently used lines

• Areas exposed to water spray

• Damaged insulation jacketing

• Low points and drainage areas

Session 4: Inspection and Detection Techniques (3:45 PM - 5:30 PM)

Finding Hidden Corrosion

Mastering inspection methods:

Visual Inspection:

• External insulation condition assessment

• Jacketing damage and deterioration

• Staining, rust bleeding, and bulging

• Missing or damaged insulation

• Wet insulation indicators

• Sealant and mastic condition

• Systematic documentation methods

Conventional NDT Methods:

• Ultrasonic thickness testing (UTT): most common

• Profile radiography: through insulation

• Real-time radiography (RTR)

• Magnetic flux leakage (MFL)

• Infrared thermography: moisture detection

• Neutron backscatter: moisture mapping

Advanced Inspection Technologies:

• Pulsed eddy current (PEC): through insulation screening

• Long-range ultrasonic testing (LRUT)

• Guided wave technology

• Electromagnetic acoustic transducers (EMAT)

• Acoustic emission for active corrosion

• Digital radiography and computed tomography

Inspection Strategy Development:

• Full insulation removal versus partial

• Screening techniques for large populations

• Focused inspection at high-risk areas

• Access and scaffolding considerations

• Production shutdown coordination

• Cost-benefit analysis of methods

Inspection Frequency:

• API 570 and API 510 guidelines

• Initial baseline inspection

• Routine inspection intervals: 3-5 years typical

• Adjusted based on findings and risk

• Seasonal considerations

• Opportunistic inspection during maintenance

Day 2: Prevention, Mitigation, and Management Programs

Session 5: CUI Prevention Strategies (8:00 AM - 10:00 AM)

Preventing CUI Through Design

Implementing prevention strategies:

Design Considerations:

• Insulation system specification: materials and design

• Jacketing selection: aluminum, stainless steel

• Vapor barrier requirements

• Drainage design and low-point elimination

• Support design minimizing insulation penetrations

• Termination design at equipment interfaces

• Access provisions for future inspection

Insulation Material Selection:

• Closed-cell versus open-cell insulation

• Calcium silicate: traditional but moisture-susceptible

• Mineral wool: moderate moisture resistance

• Cellular glass: excellent moisture resistance

• Aerogel: advanced low-conductivity option

• Non-leachable chloride requirements (<50 ppm)

• Hydrophobic coatings and treatments

Jacketing and Vapor Barriers:

• Aluminum jacketing: most common

• Stainless steel jacketing: severe environments

• PVC and polymer jacketing

• Vapor barrier membranes

• Sealants and mastics: silicone, polyurethane

• Banding and fastening systems

• Weather barrier effectiveness

Protective Coatings:

• High-performance coatings under insulation

• Thermal spray aluminum (TSA): excellent protection

• High-build epoxies and polyurethanes

• Inorganic zinc primers

• Surface preparation requirements (SSPC-SP standards)

• Application and curing conditions

• Inspection and quality control

Session 6: Mitigation and Repair Strategies (10:15 AM - 12:30 PM)

Managing Existing CUI

Implementing mitigation approaches:

Insulation Removal Decisions:

• When to remove versus retain insulation

• Cost-benefit analysis of removal

• Operational impact considerations

• Energy loss calculations

• Personnel safety during removal

• Disposal and environmental considerations

Coating Application on Existing Systems:

• Surface preparation challenges

• Blast cleaning in place

• Coating selection for existing equipment

• Application methods and access

• Cure time and temperature requirements

• Quality assurance and inspection

Insulation Replacement:

• Upgrade to improved systems

• Modern materials and designs

• Jacketing and vapor barrier improvements

• Installation quality control

• Documentation and as-built records

• Warranty and performance guarantees

Operational Mitigation:

• Temperature management strategies

• Minimizing thermal cycling

• Steam tracing optimization

• Water spray avoidance

• Drainage improvement

• Regular inspection and maintenance

Session 7: CUI Management Programs (1:30 PM - 3:30 PM)

Developing Comprehensive Programs

Creating CUI management systems:

Program Elements:

• Policy and accountability definition

• Asset inventory and data management

• Risk assessment and prioritization

• Inspection planning and execution

• Mitigation strategy implementation

• Performance metrics and KPIs

• Continuous improvement processes

Data Management:

• Insulated equipment inventory

• Isometric drawings with CUI data

• Inspection history and findings database

• Thickness measurement trending

• Risk ranking and prioritization

• Work order integration

• Document management systems

Inspection Planning:

• Master inspection plans

• Annual inspection schedules

• Resource allocation and budgeting

• Contractor qualification and management

• Quality assurance programs

• Documentation requirements

• Regulatory compliance verification

Industry Standards and Guidelines:

• API 570: Piping Inspection Code

• API 510: Pressure Vessel Inspection

• NACE SP0198: Control of CUI

• ASTM C 795: Thermal Insulation Materials

• EFC Publication 55: CUI Guidelines

• ISO 12944: Protective paint systems

Regulatory Compliance:

• OSHA PSM mechanical integrity

• EPA RMP requirements

• Insurance inspection requirements

• Jurisdictional regulations

• Environmental protection standards

• Recordkeeping and documentation

Session 8: Case Studies and Best Practices (3:45 PM - 5:30 PM)

Learning from Industry Experience

Analyzing real-world applications:

Catastrophic CUI Failures:

• Refinery piping rupture incidents

• Pressure vessel failures from CUI

• Stainless steel SCC under insulation

• Environmental releases and consequences

• Safety incidents and fatalities

• Economic impact analysis

• Root cause findings and lessons

Successful CUI Programs:

• Industry benchmark programs

• Best practice implementations

• Technology adoption success stories

• Cost savings and ROI documentation

• Organizational change management

• Culture and awareness development

Technology Applications:

• Pulsed eddy current screening programs

• Infrared thermography campaigns

• Protective coating performance

• Advanced insulation system implementations

• Robotics and drones for inspection

• Digital transformation and analytics

Interactive Workshop:

• Participant case study presentations

• Group problem-solving exercises

• CUI program development workshop

• Inspection planning exercise

• Cost-benefit analysis practice

• Action plan development

Key Takeaways and Action Planning:

• Summary of critical learning points

• Implementation roadmap development

• Resource requirements identification

• Quick wins versus long-term strategies

• Networking and knowledge sharing

• Post-course support and resources

Course Deliverables

Participants Receive:

• Comprehensive CUI technical manual (200+ pages)

• API and NACE standards excerpts

• Inspection procedure templates

• Risk assessment worksheets

• Case study compilation

• NDT technology comparison charts

• Material selection guides

• Professional certificate of completion

• Access to online resource library

• Vendor and technology directory

Interactive Learning:

• Insulation system component samples

• Corroded pipe section examination

• NDT equipment demonstrations

• Coating application videos

• Software tools for risk assessment

• Group exercises and discussions

• Q&A with industry experts

Why This Masterclass Is Essential

Key Benefits:

• Prevent catastrophic equipment failures

• Reduce unplanned shutdowns and production losses

• Optimize inspection and maintenance spending

• Enhance safety and environmental performance

• Build organizational CUI expertise

• Achieve regulatory compliance

• Implement industry best practices

Critical Statistics:

• CUI responsible for 40-60% of piping maintenance costs

• 60% of insulated assets show some CUI damage

• Average repair cost: $10,000-$100,000 per location

• Catastrophic failures costing millions

• Growing problem with aging infrastructure

ROI:

• Early detection prevents major failures

• Optimized inspection reduces costs

• Proactive prevention extends asset life

• Avoided production losses

• Reduced safety and environmental incidents

• Lower insurance premiums

Keywords: corrosion under insulation, CUI inspection, CUI prevention, insulation corrosion, pulsed eddy current, ultrasonic testing, CUI management, API 570, NACE SP0198, external corrosion, insulated piping inspection, risk-based inspection, thermal spray aluminum, protective coatings