APPLICATION OF THIN-WALLED PHASED ARRAY WITH EPRG DEFECT ASSESSMENT GUIDELINES.

Introduction

Operator experience

System Kwalification

Acceptance criteria

• API 1104 Annex A

• AS 2815-2

• EN 12732 Annex G

EPRG weld defects acceptance criteria tier 2 Limitation Overmatching weld How to perform in 4.5 to 8 mm wall thickness

Advantages Expensive CTOD testing not required Focus on relevant defects

Acceptance criteria

30 planar defects 26 special defects All defects Planar defects

Missed defects

Defects found

%

Misseddefects

Defects found

%

Found defects

%

Tolerance on averagelength(mm)

PA company X

4 87% 6 77% 82% -7,9

PA company Y

3 90% 4 85% 87% -4,8

RT 16 47% 8 70% 57% - 8,7

Acceptance criteria

Detection and length tolerance of PAUT versus RT

Acceptance criteria

EN-ISO 19285

0

0,4

0,8

1,2

0 0,4 0,8 1,2

√DR

LR

2 mm surface flaw l=t2 mm sub surface flaw 0,5 mm under surface l=t2 mm sub surface 1 mm under surface l=t3 mm sub surface 0,5 mm under surface l=0,75t3 mm sub surface 1,5 mm under surface l=t

safe region

unsafe regionL415M

DN450d= 8mm

Min KVC 27Jouleweld

Implementation

PA versus RT • Found defects• Repair %• NDT time

required

Verify the data quality before acceptance and storage

Check the presence of the correct weld overlay

Evaluation of data 2 year use

Revision of defect sizing #12

DIFFRACTION?

Negative Operator must be experienced. Lower limit of 4.5 mm. Material limited to L245/gr B. Re calibration can be time consuming.

Positive Fast method with direct results. Work kan continue no radiation issue

Survey welding contractors

Future developments

• Singel sided PA on fitting to pipe welds

• Full Matrix Capture

CT RT scanUT FMC scan

Current method fit it in a rectangleManually verify to tables of alloweddefects

3D-FEA methodModel the flaw as is in the meshof the girth weldCompute if loads can be transferred through weld with indications

Outcome

https://www.twi-global.com/technical-knowledge/published-papers/development-of-girth-weld-flaw-assessment-procedures-for-pipelines-subjected-to-plastic-straining-july-2007/

Workmanship-ECA 3D NDE methods

Automated generation of

indications in FEA mesh

MOBILE 3D-X-RAY TOMOGRAPHY FOR ANALYSIS OF PLANAR DEFECTS IN WELDS BY “TOMOCAR”

AutomatedVerification in FEA for

loads based on pre-set mechanical levels

Possible VariablesFEA MeshFEA Mechanical parameters accuracyNDT technique limitationsRequirements on load capacity