Tech Group Meeting, 23 May 2014, Chesterfield - · PDF fileTitle: Tech Group Meeting, 23 May...

Copyright © TWI Ltd 2014

Polytank

Development and Validation of an automated Ultrasonic system for the Non-Destructive Evaluation (NDE) of

welded joints in thermoplastics storage tanks


Polytank Project

• 60,000 Medium – Large Thermoplastic Industrial Storage Tanks in EU

• Attractive alternative to metal– Chemical Resistance– Longer Design Life– Cheaper Installation

• Fail by Cracking due to chemical Degradation• No established Inspection Procedures except Visual

Inspection• Reliable Volumetric NDT Technique needed


Polytank Project

• Objectives– To fabricate welded joints representative of those used in

tanks and vessels containing known flaws– To carry out long term testing of the joints with k nown flaws

in comparison with flaw free joints– To develop ultrasonic NDE techniques and procedures to

fully identify the known flaws– To analyse the ultrasonic NDE inspection data to de termine

the limits of the flaw detection– To develop an inspection system based on the ultras onic

NDE procedures which is site rugged and simple to o perate– To design and build a prototype inspection system w hich will

be assessed under both laboratory and field conditi ons


Polytank Partners

• Manufacturers– Chem Resist Group Ltd. (UK)– Technology Assistance BCNA 2010 SL (Spain)– Acutech Eisagoges Antiprosopeies EPE (Greece)– Innovative Technology and Science Ltd. (UK)

• Research Organisations– TWI (UK)– Hessel Ingenieurtechnik GhbH (Germany)– Health and Safety Laboratory (UK)

• End Users– UniVar Ltd. (UK)


Manufacture of Welded Joints


Manufacture of Welded Joints

• Determine the joint types and flaw types to be assessed

• Develop flaw insertion procedures

• Manufacture welded tank samples


Manufacture of welded joints

• Joint types

SingleSingleSingleSingle----V buttV buttV buttV butt

FilletFilletFilletFilletPipe outletPipe outletPipe outletPipe outlet


Joint / Flaw Types

• Joint types– Double-V butt


• Joint types– T-joint

Joint / Flaw Types


• Joint types– Cruciform

Joint / Flaw Types


• Joint types– Pipe outlet

Joint / Flaw Types


• Flaw types

– Lack of fusion between extrudate and parent materia l

• Simulated using embedded and partially embedded aluminium discs of diameters between 2 and 25mm

– Cracks in parent material and through the extrudate

• Simulated by machining notches of different depths into completed welds

– Cold weld between extrudate and parent material

• Generated by having no material pre-heat

Joint / Flaw Types


Flaw Insertion Procedures

• Embedded and partially embedded aluminium discs



• Cold welds

Crack along weld edge

A manually tested coldpipe-in-sheet weld

Preheat air flowdirection

Hot weld Cold weld


• Transverse cracks – T-joints and cruciform joints



Manufacture of Welded Tank Samples


Development of Ultrasonic NDE Development of Ultrasonic NDE Development of Ultrasonic NDE Development of Ultrasonic NDE TechniquesTechniquesTechniquesTechniques


WP2 WP2 WP2 WP2 –––– Development of Development of Development of Development of Ultrasonic NDE TechniquesUltrasonic NDE TechniquesUltrasonic NDE TechniquesUltrasonic NDE Techniques

• Measure basic material propertiesMeasure basic material propertiesMeasure basic material propertiesMeasure basic material properties• Develop inspection proceduresDevelop inspection proceduresDevelop inspection proceduresDevelop inspection procedures• Inspect welded samplesInspect welded samplesInspect welded samplesInspect welded samples• Design and manufacture ultrasonic Design and manufacture ultrasonic Design and manufacture ultrasonic Design and manufacture ultrasonic

probesprobesprobesprobes• Design and manufacture probe wedgesDesign and manufacture probe wedgesDesign and manufacture probe wedgesDesign and manufacture probe wedges• Develop data analysis algorithms and Develop data analysis algorithms and Develop data analysis algorithms and Develop data analysis algorithms and

softwaresoftwaresoftwaresoftware


Phased array probesPhased array probesPhased array probesPhased array probes

Optimise probe parametersOptimise probe parametersOptimise probe parametersOptimise probe parameters• Butt welded jointsButt welded jointsButt welded jointsButt welded joints


Phased array probesPhased array probesPhased array probesPhased array probes

Optimise probe parametersOptimise probe parametersOptimise probe parametersOptimise probe parameters• TTTT----jointsjointsjointsjoints


Probe wedgesProbe wedgesProbe wedgesProbe wedges

Phased array probe wedgesPhased array probe wedgesPhased array probe wedgesPhased array probe wedges• Straight butt joints Straight butt joints Straight butt joints Straight butt joints • Water wedgeWater wedgeWater wedgeWater wedge• Rexolite wedgeRexolite wedgeRexolite wedgeRexolite wedge

Open face wedgeAssembly Rexolite wedge

Membrane wedge


Probe wedgesProbe wedgesProbe wedgesProbe wedges

Phased array probe wedgesPhased array probe wedgesPhased array probe wedgesPhased array probe wedges• TTTT----joints joints joints joints • Water wedgeWater wedgeWater wedgeWater wedge


Develop inspection procedureDevelop inspection procedureDevelop inspection procedureDevelop inspection procedure

Inspection setupInspection setupInspection setupInspection setup• IIIInspection techniques for straight butt joints.nspection techniques for straight butt joints.nspection techniques for straight butt joints.nspection techniques for straight butt joints.

• Full coverage of the fusion zone

• Inspection from both sides



• Scan results for Butt Weld Joints– Aluminium disc trial sample



• Scan results for Butt Weld Joints– Trial scans



• Scan results for Butt Weld Joints



• Scan results for Butt Weld Joints



• Scan results for Butt Weld Joints– Sample with SDHs

• 40mm thick



• Scan results for Butt Weld Joints– Sample with SDHs

• 40mm thickDirect

Skip



Inspection setupInspection setupInspection setupInspection setup• IIIInspection techniques for T joints.nspection techniques for T joints.nspection techniques for T joints.nspection techniques for T joints.




• Probe with water wedgeProbe with water wedgeProbe with water wedgeProbe with water wedge– Membrane bubble wedgeMembrane bubble wedgeMembrane bubble wedgeMembrane bubble wedge




– Probe in a zero degree position on the weldProbe in a zero degree position on the weldProbe in a zero degree position on the weldProbe in a zero degree position on the weld

Sectorial scan -40°- 40°



Trial SampleTrial SampleTrial SampleTrial Sample• IIIInspection techniques for T joints.nspection techniques for T joints.nspection techniques for T joints.nspection techniques for T joints.



Trial setupTrial setupTrial setupTrial setup• IIIInspection techniques nspection techniques nspection techniques nspection techniques

for T joints.for T joints.for T joints.for T joints.– Probe in Probe in Probe in Probe in position in position in position in position in

water bath showing water bath showing water bath showing water bath showing position of SDHposition of SDHposition of SDHposition of SDH



Direct inspectionDirect inspectionDirect inspectionDirect inspection

Edge of Unweldedarea

Weld cap



Fusion face Fusion face Fusion face Fusion face –––– no flawsno flawsno flawsno flaws Fusion face Fusion face Fusion face Fusion face –––– 2 flaws (SDH)2 flaws (SDH)2 flaws (SDH)2 flaws (SDH)



Skip inspection Skip inspection Skip inspection Skip inspection –––– top of base platetop of base platetop of base platetop of base plate

Remote weld cap

Weld cap



Skip inspection Skip inspection Skip inspection Skip inspection –––– top of base top of base top of base top of base plate plate plate plate ---- 2 2 2 2 flaws (SDH)flaws (SDH)flaws (SDH)flaws (SDH)



Skip inspection Skip inspection Skip inspection Skip inspection –––– base of bottom platebase of bottom platebase of bottom platebase of bottom plate

Remote weld cap

Weld cap


Inspect welded samplesInspect welded samplesInspect welded samplesInspect welded samples

Inspection of Butt weldsInspection of Butt weldsInspection of Butt weldsInspection of Butt welds• 25mm thick BW plate25mm thick BW plate25mm thick BW plate25mm thick BW plate

S-scan B-scan

Good partRoot signal

Cap signals




S-scan B-scan

Unwelded areaLOF




S-scan B-scan

Deformed cap




• Aluminium discsAluminium discsAluminium discsAluminium discs• Direct specular reflection from lower fusion face

90°skew

270°skew




• Aluminium discsAluminium discsAluminium discsAluminium discs




• Aluminium discsAluminium discsAluminium discsAluminium discs• Sizing of discs• Direct specular reflection

S-scan B-scan

2mm


Analysis softwareAnalysis softwareAnalysis softwareAnalysis software

A software platforms are being created for analysis of A software platforms are being created for analysis of A software platforms are being created for analysis of A software platforms are being created for analysis of inspection datainspection datainspection datainspection data• The analysis will be performed after the inspection.The analysis will be performed after the inspection.The analysis will be performed after the inspection.The analysis will be performed after the inspection.


TomoView PolyTank Software

• Olympus proprietary software• Requires proprietary USB

license key for every usage• Everything locked down for

adding new features• Industry benchmark

• Bespoke software for PolyTank project

• Custom features appropriate for project data

Analysis softwareAnalysis softwareAnalysis softwareAnalysis software


Current softwareDisplays All compatible files

Displays Data in various views

Custom Data Manipulation

PolyTank

Still in early stage of development


Sheet 1

Constant loadExtrudate(double V

weld seam)

Sheet 2

Creep rupture testsof Double-V butt welds

Development of Acceptance criteria


Testing of Double-V butt weld

Test Fluid

Weight

Time Record

Welded specimen

Test Bath

Lever Arm

Pump / Heating



Fracture behaviour of double-V butt weldReference weld without flaws (15 mm sheet)

SheetSheet

Extrudate

CrackFailure plane

Side viewTop view (sheet)

Crack starts from the outside



Fracture behaviour of double-V butt weld Specimen with embedded aluminium disc (ø15 mm)

Sheet

Extrudate

Fracturesurfaces(Top view)

Sheet

Extrudate

Mark ofthe disc Disc

Failure in the fusion plane

Upper half of the specimenLower half of the specimen



Constant load

Tank-wall

PipeExtrusion weld

Machine base

Counter-holder

Creep rupture testsof pipe in sheet welds



Control unit

Data record

Universaltestingmachine

Sample

Test bath

Temperaturesensor

Constant load

Heatexchanger



Some results of pipe in sheet welds

Reference weld without flaws

Brittle failure outsidethe fusion plane inthe parent material(sheet)



Partially embedded 25 mm Al disc

Some results of pipe in sheet weldsBrittle failure outsidethe fusion plane inthe parent material(sheet)

Rupture time in thesame range ofreference weld



Welds

Air compressor suction cups (actuated)

Single axis Actuator (Y-axis)Single Axis Actuator (X-axis)

Probes

Cylinder to apply a constant contact force (Z-axis)

Flaw detector

Integration and Validation of Inspection System


Further workFurther workFurther workFurther work

Planned work for the next monthsPlanned work for the next monthsPlanned work for the next monthsPlanned work for the next months• Select inspection techniques for each joint geometry on Select inspection techniques for each joint geometry on Select inspection techniques for each joint geometry on Select inspection techniques for each joint geometry on

the test the test the test the test specimens.specimens.specimens.specimens.• Manufacture Manufacture Manufacture Manufacture probe probe probe probe wedgeswedgeswedgeswedges• Finalise the inspection procedureFinalise the inspection procedureFinalise the inspection procedureFinalise the inspection procedure• Inspect samplesInspect samplesInspect samplesInspect samples• Finalise softwareFinalise softwareFinalise softwareFinalise software• Carry out field trialsCarry out field trialsCarry out field trialsCarry out field trials


– This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 313950

– The information in this document is provided as is and no guarantee or warranty is given that the information is fit for any particular purpose. The user thereof uses the information at its sole risk and liability

– Copyright © PolyTank SME Consortium Members

Polytank Project


Polytank Project

Thank You

• Malcolm SpicerTWI Ltd

• Tel: +44 (0)1223 899 000E-mail: [email protected]

• Web: www.twi-global.com

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Tech Group Meeting, 23 May 2014, Chesterfield - · PDF fileTitle: Tech Group Meeting, 23 May...

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