Eddy Current As Alternate Method for Inspection of Welded Joints

CINDE June 2015

Dave Jankowski (USA) and Dave Perrett (UK)Product Support LeadersGE Inspection Technologies

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Inspection of welded joints for surface breaking cracks is required in most

land based and off-shore petro-chemical facilities

Surface breaking cracks can lead to catastrophic failure if undetected and

not repaired

Traditional Weld Inspection MethodsLiquid Penetrant and Magnetic Particle

Advantages

• Reasonable cost

• Portable

• Minimal inspector training

• Easy Interpretation of data

Dis-Advantages

• Coating must be removed prior to inspection then re-applied

• Disposal of chemicals

• Time consuming

• Scaffolding often required

• No digital documentation of indications

EN 1711 (Mar 2000)Eddy Current Examination of Welds by Complex

Plane AnalysisRecently Converted to ISO/DIN 17634 Standard

Other Approvals

• Lloyds Register• DNV (Det Norske Veritas)• Bureau Veritas

EN 1711 (Mar 2000)

EN 1711 (Mar 2000)

EN 1711 (Mar 2000)

EN 1711 (Mar 2000)

EN 1711 (Mar 2000)

LP Inspection Time

Paint Stripping& Cleaning

Penetrant Application &

Dwell

Developer Application &

Dwell

Inspection

Post CleanRepainting

Surface Prep

Inspection

Eddy Current Inspection

Time

2.5 to 3:1LP to EC

LP Inspection Time

Paint Stripping& Cleaning

Penetrant Application &

Dwell

Developer Application &

Dwell

Inspection

Post CleanRepainting

LP/MP Cost

Certified Inspector

Consumables

Capital Equipment

Compliant Disposal of Consumables

EC Cost

$ $$$

None$$$

$ $$$$

None$$$$

LP Versus ECInspection Cost Comparison

Hyperlink to .xls

Penetrant Inspection - 6 off Joints

Task Time Taken (mins) Time/C ost Typical Timings/C osts

Paint removal 40 min s 40 mins

Inspection pre-clean 18 min s 18 mins

Penetrant Application 12 min s 12 mins

Penetrant Dwel l 20 min s 20 mins

Excess Penetrant Removal 18 min s 18 mins

Developer Appl ication 6 min s 6 mins

Developer Dwell 10 min s 10 mins

Evaluation 18 min s 18 mins

Post-clean 18 min s 18 mins

Repainting 20 min s 20 mins

Total Time Take n 3.0 hours 3 hours

Man Hour Rate 24$ US$

Total Man Hour Costs 72$ US$

Consumables, includ ing scaffolding

costs if applicable 60 US$ Min $10/joint

Total Inspe ction Cost 132$ US$

EC Weld Inspection - 6 off Joints

Task Time Taken Time/C ost Typical Timings/C osts

Surface Prep 0.25 hours 15 mins = 0,25 hrs

EC Inspection 1 hours 1 ho ur

Man Hour Rate 60$ US$

Total Inspe ction Cost 75$ US$

SAVI NG U S$ 57$ US$

TIME SAVING 2 hours

Liquid Penetrant Vs. Eddy Current of Welded Jo ints

10" Diame ter P ipe 6 off jo ints inspected

LP Versus ECInspection Cost Comparison

Number of Inspections

Cost

of

Insp

ection

s

Hyperlink to .xls

Middle East 250,000 Barrel Per Day RefineryLP Inspection Costs During Shutdown

~ 10,000 Weld Joints for Cracks

• 500 cans of penetrant aerosols ~ $6,500

• Total Inspection Time: ~5,000 hrs.• ~2,100 hrs. for LP• ~2,900 hrs. for pre and post Inspection tasks

Middle East 250,000 Barrel Per Day RefineryLP Inspection Costs During Shutdown

~ 10,000 Weld Joints for Cracks

• 500 cans of penetrant aerosols ~ $6,500

• Total Inspection Time: ~5,000 hrs.• ~2,100 hrs. for LP• ~2,900 hrs. for pre and post Inspection tasks

Eddy Current: ~1,700 hrs. for entire inspection withno consumables

Eddy Current Inspection of Welds

Field proven EC probe designs minimize impact

of rough surfaces

StandardHigh Wear Ceramic Tip

High Temperature(425F/220C)

Eddy Current Inspection of Welds

Field proven EC probe designs minimize impact

of rough surfaces

StandardHigh Wear Ceramic Tip

High Temperature(425F/220C)

Minimal Lift Off Effect Due to Rough Weld Surface

Eddy Current Inspection of WeldsGuided Workflow Helps Ensure Consistent Inspection and Reduce Error Traps

Digital Documentation of Weld Indications

Collaboration with Remote Experts

CloudServices

ConnectedDevices

WebPortal

More accurate and efficient inspections

Real-time access to knowledge from off-

site experts

Real-time sharing of inspection data

Digital Gain Control (DGC) to Compensate for Varying Coating Thicknesses

As coating/paint thickness varies across a weld, gain automatically readjusted to ensure inspection sensitivity

Summary

• Eddy current is an ISO (EN) approved inspection method for welded joints

• Eddy current offers distinct advantages over LP/MPI

• No consumables to purchase

• No consumables to dispose of

• No need to remove coatings prior to inspection

• Digital record of inspection

• Simple financial analysis can identify break even point for EC inspection compared to LP/MPI

• Guided workflows and remote collaboration can further enhance weld inspections

• Digital Gain Control further improves weld inspection productivity

GE Inspection TechnologiesMentor EM for Weld Inspection