Standard Guides:Welding Piping ASME API Asset Matrix

🐘 Tusker VaultAdvancedElectromagnetic • PEC

Pulsed Eddy Current (PEC)

Method Overview

Measurement of wall thickness through insulation, fireproofing, or coatings to screen for Corrosion Under Insulation (CUI).

Core Method Specifications

Technique IDPEC

AcronymPEC

CategoryAdvanced

ModalityElectromagnetic

Standardized Report TemplateISO 17020 Ready

PEC-Standard-TemplateTest in Sandbox

Target Applications & Governing Standards

2 Scopes Configured

Piping & Loops

API 570 ISO 20669

Target Assets / Components:

Insulated Piping LinesFireproofed Legs

Detectable Defects & Anomalies:

• Corrosion Under Insulation (CUI)• Under-jacket Thinning

Storage Tanks

API 653

Target Assets / Components:

Insulated Tank SkirtsTank Annular Rings

Detectable Defects & Anomalies:

• Skirt Corrosion• Bottom Plate Corrosion

Method Limitations & Operational Boundary Conditions

Critical physics limits, thermal envelopes, blind spots, and ASME Sec V / API procedural boundaries for PEC.

Level III Procedure Control

Operating Temp Envelope

Standard Envelope-20°C to +80°C (-4°F to 176°F) ambient probe housing

High-Temp CapabilityUp to 500°C (932°F) continuous pipe surface temp using ceramic heat-shielded probe shoes

Component metal temperature must be entered into software algorithm to calculate proper electrical conductivity curve.

Thickness & Dead Zone

Min Thickness6.0 mm (0.24 in) minimum wall thickness

Max RangeUp to 65 mm (2.5 in) steel wall thickness; lift-off insulation thickness up to 200 mm (8.0 in)

Near-Surface Dead Zone

Measures average wall volume within probe electromagnetic footprint; cannot differentiate OD from ID loss

Surface Condition & Couplant

Roughness & PrepNo surface prep required; scans through aluminum/stainless jacketing, insulation, and marine growth

Coating ToleranceTolerates up to 200 mm (8 in) of thermal insulation (mineral wool, calcium silicate, cellular glass, asbestos)

Couplant / Media

None

Geometry & Orientation

Orientation Sensitivity

Measures volume loss within magnetic footprint. Insensitive to crack orientation

Clearance:Sufficient clearance to position probe head against outer cladding insulation jacket

Critical Blind Spots

•Isolated small pinhole pitting: Discontinuities with diameter smaller than probe footprint diameter are averaged out and severely undersized
•Cannot differentiate whether wall loss is external (CUI) or internal process-side erosion
•Severe signal distortion near galvanized steel insulation cladding or chicken wire mesh reinforcement

False Indication Trap:

Varying thickness of weather jacketing lap bands or steel strapping mimicking localized metal loss

Recommended Cross-Validation

UTView Method

Targeted insulation plug removal and high-precision UT thickness gauging at locations flagged by PEC

DRView Method

Profile digital radiography to visually examine pipe wall silhouette through insulation

Level III Code Compliance Directive:ISO 20669 mandates establishing baseline decay reference signals on nominal wall thickness of identical alloy and insulation stand-off.

Technique-to-OEM Compatibility Matrix

Verified manufacturers, instrument models, and diagnostic portals supporting PEC.

4 Verified OEMs

Eddyfi Technologies

Advanced non-destructive testing conglomerate encompassing Eddyfi electromagnetic arrays, Silverwing tank floor scanners, Teletest guided waves, Inuktun robotic crawlers, and M2M phased array instruments.

Modalities:ETMFLPAUTACFMPEC+6 more

OEM Profile Eddyfi Support Center

OEM Site