AWJ 2013 Issue 3.pdf

Volume 58, Third Quarter, 2013

journal

published by the Welding Technology Institute of Australia

and welding Research Supplement

PRINT POST APPROVED PP 255003/01892

This issue: Inspection and Testing

A Member of The Linde Group

Shielding gas?Equipment?Consumables?Welding procedure?

Safety?

BOC can help you withthe right combination

TitaniumSeriesAUTO-DARKENINGWELDING HELMETSINTEGRATEDGRIND SHIELDProvides 180 eld ofview while grinding.High Impact. *Availableon 9400i model only.

EXCLUSIVE!INFOTRACKTECHNOLOGYTrack arc time whilewelding. With digitalclock and alarm.

SUITS HIGH AMPAPPLICATIONSThe aluminium heatshield protects the lenswhile the shell reectsheat to assist in keepingthe helmet and user cool.

AUSTRALIAN STANDARDSComplies to Australian Standards.AS/NZS1337.1 and AS/NZS 1338.1.

3 YEAR WARRANTYAuto-darkening lens only.

welding.com.au1300 300 884

More info

welding.com.au

featuresOfficial publication of the

Welding Technology Institute of Australiaincorporating the Welding Research Supplement

Front Cover

Eric SjerveTrends in NDT in the industrial marketplace

3

Sean NorburnOptimising inspection planning and asset integrity management using fitness-for-service methods6

WorldSkills Leipzig 2013

10

Warwick Payten New tools for life assessment of aging power plant12

At BOC, we understand the challengesyour business faces everyday. If we canhelp you increase productivity and keepcosts down, then were doing our job.We recognise that for welding, itsimportant to use the right combinationof BOC shielding gases, quality weldingconsumables, and state-of-the-artwelding machines to help you achievethe results you need. In addition tothis, BOC has a wealth of technicalexpertise available to you through ourWelding Specialists located in majorregions across Australia.Just as we protect our own people,you can count on BOCs commitmentto help protect yours. We have acomprehensive range of personalprotective equipment and workwearspecifically designed for your workers.To find out more, visit your local Gas& Gear retail outlet, www.boc.com.auor call 131 262.

BOC LimitedRiverside Corporate Park10 Julius Avenue, North RydeNSW 2113 [email protected] is a trading name of BOC Limiteda Member of The Linde Group. BOC Limited 2013.

advertisers indexAttar...........................................21BOC......................................... FC, 9Chemetall...................................... 7Donaldson Filtration......................11Gullco International Pty Ltd...........11Harris Products Group.................. 5NDT Equipment Sales Pty Ltd......15Olympus Australia Pty Ltd............BCQuest Integrity Group....................15Smenco......................................... 3WIA / Miller................................ IFC

Roger GriffithsCorrosion under insulation debunking the myths

14

National Structural Steel Compliance Scheme

16

Richard Nowak Developments in ultrasonic weld inspection

17

Asia Pacific IIW Congress Singapore

19

Rachel Lieberman Digital radiography of ships

20

regularsEric Sjerve

Editorial Comment

AICIP News

WTIA OzWeld School of Welding Technology

22122

Qualification and Certification 24

Hotline Report

29

Around the Regions

30

For Your Diary

49

welding research supplementRichard Clegg, Effect of weld toe treatmentsAlan McLeod on the fatigue resistanceand of structural steel weldsWilliam Ruddell

34

Ninh NguyenFitness-for-service and defectand tolerance assessment Eric De Beer solutions for cracked components to remain in service42

WTIA Goal To lead and assist in makingAustralian industry locally and globallycompetitive in welding-related activitiesAUSTRALASIAN WELDING JOURNAL VOLUME 58, THIRD QUARTER 2013

1

COMMENT

NDTs Essential RoleP

ublic safety and aging plant are probablythe two most important challenges facing plant owners andoperators today. Public safety and the safety of personnel working at the plant sites are usually the most important factors whenmaking maintenance decisions and awarding contracts.

Extending the service life of aginginfrastructure is a common problem forcompanies and governments in all firstworld countries. The high consequenceof failures that make news stories aroundthe world has brought this problem verypowerfully to peoples attention. Thereis a lack of public tolerance for failures,particularly those causing loss of lifethat could have been prevented if thecorrect maintenance was done. By usingengineering fitness-for-service assessments, partial rebuilds, and focused NonDestructive Testing (NDT), organisationsare extending the serviceable life of aginginfrastructure rather than re-building. Thisis a common trend in many industries andit has resulted in an increasing proportionof in-service NDT being done, in relationto the entire NDT market.Emerging economies face the difficult challenge of rapidly developing therequired infrastructure to acceptable standards for public safety and environmentalmanagement within restricted economicand local skills base resources. Often,globally based companies are managingmultiple large scale projects in these locations, while trying to meet the infrastructure requirements of local economies. Inmost cases, the construction and inspectionis completed using the existing industrialbest practices documents, developed inother parts of the world. This leads to achallenging environment with many peoplefrom different cultures working togetherto meet tight deadlines.Both of these trends have resulted in alarge industry that supports the life extension of aging infrastructure as well as theconstruction of new infrastructure projects.NDT is part of this trend as the inspection

Dr Eric Sjerve is Chairman of the InternationalInstitute of Welding (IIW) Commission V NDT andQuality Assurance of Welded Products. Based in Canada at IRISNDT Corp., aninternational company providing NDT and quality assurance solutions to a diverse baseof industrial customers, he is Vice President Corporate Technology Development.

are deployed, often with the aid of computer simulation; this provides betterprobability of detection (POD) and moreaccurate defect sizing for fitness for serviceevaluations.Digital Detector Array radiographyensures correct splicing of a highvoltage cableof newly fabricated components, as wellas detection of in-service flaws, plays anessential role. Managers are continuallyfaced with deciding what type of NDT touse and how much.

Development of NDTIn recent years, the field of NDT has beenin a state of rapid advancement. In thepast, NDT was performed using analoginstruments. The signals were interpretedat the job site without a permanent recordof the work completed, except for thehand written reports summarising theinspection results.NDT was divided into five basic disciplines: ultrasonic testing (UT), radiographic testing (RT), eddy current testing(ET), magnetic particle testing (MT) andliquid penetrant testing (PT).In contrast, modern application ofNDT has grown into a diversified fieldthat includes many new techniques inaddition to the basic five methods.For many inspections, advanced NDTtechniques or multiple NDT techniques

Phased Array ultrasonic and TOFD weld inspection

2 AUSTRALASIAN WELDING JOURNAL VOLUME 58, THIRD QUARTER 2013

NDT reports are typically electronic,often providing a full data set to allowauditing or comparison with future inspection results for flaw growth monitoring.Qualified people, specialising in specificNDT techniques, can then analyse thedata via wireless access from other citiesor countries. The tremendous growth ofrelatively cheap and powerful computingcapacity has driven much of this advancement; it is unusual to find a modern inspection system that is not digital with somelevel of on-board computational ability.The International Institute of Welding (IIW)provides a forum for thecontinual advancementof welding and inspectiontechnologies, and Commission V NDT andQuality Assurance of Welded Products isattended by experts from around the world.Advances and trends in NDT technologies in the industrial marketplaceare overviewed in an article by Dr. Sjerveon page 4 , based on the work of the foursub-groups within this Commission: Sub-commission VA: RadiographicBased Weld Inspection Techniques Sub-commission VC: Ultrasonic BasedWeld Inspection Techniques Sub-commission VE: Weld Inspection Techniques Based on Electric,Magnetic and Optical Methods Sub-commission VF: NDT ReliabilityIncluding Simulation of NDT TopicsAustralians interested in participatingin this IIW forum, or learning more aboutIIW activities, should contact the WTIAas the IIW Australian Member Society [email protected]

Performancewithoutcompromise

SMENCO & Hypertherm the newforce in cutting technology

SMENCOs long-standing relationship with Hypertherm hasexpanded and we now offer technology based solutions foryour processing needs using:

Powermax hand held & mechanised systemsMAXPRO hand held & mechanised systemsHyPerformance Plasma (HPRXD)CAD/CAM Nesting SoftwareCNC & Robotic solutionsTorches & Consumables for all Hypertherm systems

SMENCO - Offices in Melbourne,Sydney, Brisbane & Perth

FREE CALL 1300 731 873

|

www.smenco.com.au

AUSTRALASIAN WELDING JOURNAL VOLUME 58, THIRD QUARTER 2013

3

TRENDS IN NDT

Trends in NDT in the industrial marketplaceSC-VA: Radiographic basedweld inspection techniques

Digital radiographic techniques arerapidly entering the NDT market, withcomputed radiography (CR) and digitaldetector array (DDA) based radiographictesting now acceptable to code. Optimiseddigital techniques can provide substantialimprovements compared to film basedradiography in contrast sensitivity, exposure reduction and radiographic sensitivity. In addition, these techniques providedigital images that are easier to handle thanfilm. Applications with battery poweredX-ray tubes enable the reduction of thecontrolled radiation area and substitutionof gamma sources.Although not as common in theindustrial field, computed tomography(CT) and its variations give extremelydetailed images and enable the accuratedimensional measurement of flaws andstructures. New standards and trainingcourses have been established for digitalindustrial radiology supporting the application of these new techniques.IIW has been actively revising reference radiographs to incorporate the useof modern digital radiography for theinspection of castings and welds.

SC-VC ultrasonic based weldinspection techniquesThe introduction of phased array ultrasonictesting (PAUT), and its subsequent widespread adoption for many industrial inspections, is probably the biggest advance inthe field of ultrasonic testing over the pastten years. PAUT is similar to ultrasonictesting, except a multi-element PAUTtransducer replaces a conventional singleelement ultrasonic transducer. This allowselectronic control of ultrasonic sound beamproperties: angle of sound, wave mode,mechanical rastering and focal properties.PAUT is now ubiquitous in industry,due to the inspection flexibility it providesand the easily available battery operatedcommercial equipment. Industrial implementation of PAUT equipment requiresadditional operator training comparedto conventional ultrasonic testing. Thesub-commission recently published anIIW Phased Array Handbook, which isavailable for purchase.Efforts are underway to commercialise extensions of PAUT involving moreadvanced data acquisition techniques andsignal post-processing (e.g. full matrixcapture, sampling phased array and totalfocussing method) to allow more accurate

flaw characterisation. The sub-commissionis also leading a project to re-design the IIWcalibration block specifically for PAUT.

Guided wave testing (GWT) is anotherultrasonic inspection technique that israpidly advancing. It is most commonlyused for rapidly screening piping systemsfor cross sectional wall loss. The remaining wall thickness of corroded areas isgenerally not assessed. Commerciallyavailable GWT systems can focus andperform frequency sweeping on ambient or high temperature piping, allowingbetter signal-to-noise ratios on flaws byconcentrating sound intensity at optimumfrequencies at the flaw location. IIW hasbeen involved with initial GWT standardisation efforts, with an IIW written ISOStandard to soon be released specificallydealing with piping inspection.

SC-VE weld inspectiontechniques based on electric,magnetic and optical methodsThis sub-commission has a very broadscope, and in the past has been most activein the area of magnetic metal memory(MMM). MMM is a passive magnetictechnique that detects areas of residualstress that are correlated to degradationmechanisms. There exists a large body ofexperience in this area, but one promisingapplication is the ability to detect wall lossin buried piping systems without havingto expose the pipe.Current discussion focuses in two areas.The first is on the quantification of automotive industry spot weld quality; it usesa flash filter to rapidly heat the weld andan infrared (IR) camera to measure heattransfer into parent material. The secondis on the use of giant magneto-resistance

Leading from his Editorial Comment on page2,Dr. Eric Sjerve, Chairman, International Instituteof Welding (IIW) Commission V NDT and QualityAssurance of Welded Products and Vice President Corporate Technology Development,IRISNDT Corp., Canada, reviews the latestadvances in NDT within the framework of thefour Sub-commissions of the IIW Commission V.

(GMR) sensors for detection of magneticfields. GMR has been shown to have highsensitivity to surface breaking flaws, allowing accurate and detailed flaw detectionfor cracks as small as 10 microns deepand 1 mm long.As a further promising surface inspection technique of welds, laser based thermography also shows very high sensitivity.It can be applied by using a laser scannerand an IR camera and is thus completelycontact free. It has been shown that laserthermography can detect surface breakingcracks with extremely small crack openings in the sub-micron range even at highlaser beam velocities of more than 1 m/s.This sub-commission also has discussedin-line inspection (ILI) using electromagnetic acoustic transducers (EMAT)and structural health monitoring (SHM).EMAT sensors are now used in ILI gaspipeline pigs to perform ultrasonic inspection, magnetic flux leakage inspectionand eddy current lift-off measurements.The SHM field is at an early stage forindustrial applications, but this areaholds much promise by locating sensorsin-situ on equipment to provide real-timeinformation on operating conditions. Onesuch application is the use of birefringentoptical sensors in the wings of aircraftto gather real-time information on thestresses they are exposed to, which is thenused in finite element models to predictmaintenance requirements and estimatelife times.

SC-VF NDT reliability includingsimulation of NDT

Simulated Iridium 192 radiograph of asingle V weld with an inclusion


Simulation has become a very importantaspect of NDT, as it allows inspectionsto be modelled using software of variouslevels of sophistication to provide a relatively inexpensive method of determininghow a particular inspection procedurewill perform on a specific component.In its most basic form, modelling mayfulfil ASME Code criteria to provide anultrasonic scan map using a ray tracingprogram to show weld inspection coverage. Modelling can also be used to predictresponses of postulated defects in a weldedjoint and to give the minimum size of(Continued on page 6)

COLUMN HEADING

MadeinEurope


5

FITNESS-FOR-SERVICE

Optimising inspection planning and asset integritymanagement using fitness-for-service methodsIntroductionThe inspection of assets typically foundin power and process plants is not onlycostly; it requires careful planning andpreparation work. This article illustrateshow Quest Integrity Group uses fitnessfor-service methods such as API 579/ASME FFS-1 [1] and BS 7910:2005[2] to optimise inspection programmesand minimise the amount of inspectionrequired, therefore reducing down-timeand the associated loss in revenue.Upon finding defects, these methodscan also assist in decision making regarding the most appropriate course of actionto take. This could be repair, replace orre-rate. In some instances, the repair maybe unavoidable, but with the knowledge ofremaining life or safety factors it may bepossible to delay the repair until appropriate procedures are developed.

Pre-inspection assessment

Advanced techniques such as finite element analysis are used to determine whereplant equipment has been subjected to thehighest levels of stress, strain or damage.This technique requires knowledge of theequipment geometry, which can eitherbe obtained from available engineeringdrawings or an on-site dimensioningsurvey. The materials of fabrication andthe operational loading of the equipmentare also required. Once this informationis available, a finite element model canbe developed and the stresses, strains,

Sean Norburn, Senior Consultant Structural Integrity, Quest Integrity Group

Figure 1. Stresses calculated by finite element analysis in a high energy steampipework assessmentdisplacements and temperatures can bedetermined using finite element analysis.This technique has been successfullyapplied on many occasions for QuestIntegrity clients operating high energysteam pipework, where there are potentially many welds to inspect. Use of finiteelement analysis combined with advancedcreep damage algorithms helps identify thewelds most at-risk from exhausting theiravailable creep life due to operation atelevated temperatures and pressures. Usinga prioritised risk ranking of each weld inthe pipework significantly reduces thenumber of welds to inspect, and thereforereduces the associated down-time and lossin revenue for the client (see Figure 1).Quest Integrity also performs fitnessfor-service assessments prior to inspection

for clients that own large atmosphericchemical storage tanks (see Figure 2).These assessments are based on finiteelement analysis to determine locationsof high stress, which in turn are used todetermine the associated critical flaw sizes(the size of defect or flaw at which tankrupture could occur).Fitness-for-service codes offer guidelines on how to compute such criticalflaw sizes, however Quest Integrity hasdeveloped specialised software, SignalFitness-For-Service (FFS) [3], whichautomates the implementation of fitnessfor-service standards API 579/ASMEFFS-1 and BS 7910.In addition, if cracks are found in atmospheric storage tanks that require removalby grinding, local thinning analysis can(Continued on page 8)

Trends in NDT(Continued from page 4)defect which can be detected. In the mostcomplicated configurations, modellinginvolves full beam propagation modelsshowing ultrasonic beams propagatingthrough anisotropic microstructures.NDT simulation is also being used tosupport probability of detection (POD)studies. POD round robin trials usingphysical reference blocks are often prohibitively expensive, whereas simulationcan be used to reduce cost by reducingthe number of reference blocks required.As an added benefit, simulating realisticdefects often provides an improvement inPOD reliability, over machined artificialflaws in physical reference blocks; it canalso quantify the influence of uncontrolledparameters. This sub-commission has beenactive in developing guidelines for the useof simulation in NDT, and has recentlypublished an IIW Booklet that outlinessteps on how simulation should be usedand tested to ensure accuracy.

Figure 2. Fitness-for-service assessment of atmospheric chemical storage tank


Contact 1800 008 738

FITNESS-FOR-SERVICE

Figure 3. Illustration of life extension through life assessment and inspectiondetermine how much metal loss can bepotentially tolerated at the tank wall orfloor without compromising safety. Performing assessments such as this priorto a weld inspection programme has theadvantage of reducing the lead time associated with defect repairs significantly andthus corresponds to a significant reductionin down-time for the plant.

Post-inspection assessment andon-going asset managementUpon finding defects, assessment methods based on advanced techniques suchas finite element analysis enable assetowners to understand whether or not theycan run the equipment safely, or whetherthey need to lower the operational loading(re-rate), or alternatively repair.In the instance that a repair is required(perhaps the assessment concluded that

the defect was too large relative to thecalculated critical flaw size), a fitnessfor-service assessment approach is usedto investigate the proposed repair scenarioand ensure that the repaired equipment isfit-for-service. If the equipment is subjected to fatigue loading (cyclic, repeatedloading over time), the number of repeatedload cycles to grow the defect, sized by aNon Destructive Inspection (NDI) method,to the calculated critical flaw size can bereadily calculated using Signal FFS. Inother words, these advanced methodsare used to calculate the remnant life ofthe equipment based on the rate of crackgrowth associated with the future operation of the equipment.Furthermore, asset life extension philosophies such as safety-by-inspectionor retirement-for-cause enable the life ofassets to be extended in a safe and efficient

manner. With these approaches, there isalways a conservative assumption thatflaws exists at all welds and are growingunder service loading. The remnant lifeassociated with the time for these flaws togrow from the minimum detectable flawsize (associated with some NDI technique)to the critical flaw size is calculated usingfracture mechanics. The inspection intervalis determined by dividing the calculatedremnant life by an appropriate safetyfactor. Then repeated application of theassociated NDI technique at the criticalweld locations is performed during the lifeof the asset (see Figure 3). If no defectsare found with subsequent inspections,then the assumed flaw size is re-set to theminimum detectable flaw size of the NDItechnique. Thus a decision on repairingor retiring is only required when a flawis actually detected after many years ofservice beyond the original manufacturersstated design life.The assessment of equipment subjectedto environmental cracking can also beperformed through fitness-for-servicemethods. Figure 4 summarises stress corrosion cracking found in a reducer coneweld that is associated with a particularpiece of high-temperature plant exposed toa corrosive environment. The assessmentsized the repair weld that was required toguarantee 18 months of continued safeoperation. This 18 month target was set bythe asset owner to reach the next plannedmajor outage when extensive repairs onthe plant could be adequately planned for.This assessment was also based on finiteelement analysis to ascertain the levels ofstress at the weld and critical crack sizecalculations, as well as a leak-before-breakassessment as outlined in BS 7910:2005.

SummaryFitness-for-service methods involvingadvanced analysis techniques such asfinite element analysis optimise large weldinspection programmes by locating andprioritising the most at-risk welds, whichconsequently reduces down-time and theassociated loss in revenue for the assetowner. Asset management programmeshave also benefited from using fitnessfor-service methodology to support lifeextension programmes and assessmentof suitable repair methods.

References

Figure 4. Summary of weld repair sizing and life assessment


1. The American Petroleum Institute and AmericanSociety of Mechanical Engineers, Fitness-forService API 579/ASME FFS-1 (API 579 SecondEdition). API Publishing Services June 5,2007. 2. British Standard Institution, BS 7910:2005,Guide to methods for assessing the acceptabilityof flaws in metallic structures. 3. Quest Integrity Group, Signal Fitness-ForService version 4.0, 2013.

A Member of The Linde Group

BOC can help you withthe right combinationShielding gas?Equipment?Consumables?

Weldingprocedure?Safety?

At BOC, we understand the challenges yourbusiness faces everyday. If we can help youincrease productivity and keep costs down, thenwere doing our job.We recognise that for welding, its important touse the right combination of BOC shielding gases,quality welding consumables, and state-of-the-artwelding machines to help you achieve the resultsyou need.In addition to this, BOC has a wealth of technicalexpertise available to you through our WeldingSpecialists located in major regions acrossAustralia.

Just as we protect our own people , you can counton BOCs commitment to help protect yours. Wehave a comprehensive range of personalprotective equipment and workwear specificallydesigned for your workers.To find out more, call 131 262, visit your localGas & Gear retail outlet or boc.com.au

BOC Limited

Riverside Corporate Park, 10 Julius Avenue, North Ryde, NSW 2113 [email protected] is a trading name of BOC Limited, a Member of The Linde Group. BOC Limited 2013. MP13-0026-3|ML|AWJ|0913

Like

WORLDSKILLS

Leipzig2013Over 1,000 competitors, 2,000 experts, 3,000 volunteers and 200,000 visitorsconverged on Leipzig, Germany in July this year for the 42nd WorldSkillsInternational Competition the biggest WorldSkills International event to date.The 2013 Team Australia Skillaroos wereselected following their performances atthe 2012 WorldSkills Australia NationalCompetition in Sydney. Australia wasrepresented by 31 young, proud and determined skill and trade technicians, whocompeted in a wide range of categoriesincluding Industrial Control, Hairdressing, Polymechanics/Automation, FashionTechnology, Sheet Metalwork, Manufacturing Team Challenge and of courseWelding and Construction Steel Work.The Skillaroos were up against evenstronger competition than in previous yearswith 54 WorldSkills Member countries/regions now competing internationally, anumber which continues to grow.Australia took home 19 medals, including one gold (Timothy Taylor Automobile Technology), two silver (JessicaMartin Restaurant Service and TayronScagnetti Jewellery, one bronze (LachlanMayled Welding) and 15 Medallions ofExcellence, securing a ranking as the 13thbest nation in the world.

Welding categoryThirty-five countries competed in thewelding competition, the largest categoryof competitors at the international competition. Australian competitor LachlanMayled came home with the bronze medal,an excellent achievement in the face ofsuch strong international competition.Korea took out the gold medal, and USAand Brazil tied for Silver.WorldSkills Australia reports thatwelding is a family affair for Lachlan. Hefirst became interested in the trade afterhelping his father, also an experiencedwelder, in the backyard shed. Whilst atschool, Lachlan was given the option toselect metal work as an elective, a naturalchoice for the budding welder. He laterenrolled in an evening course at InverellTAFE whilst completing years 9 and 10.During year 11, he commenced a schoolbased apprenticeship working alongsidehis father in the family business.Lachlan completed his Certificate IIIin Engineering at TAFE NSW, ArmidaleCollege. He now works for Binderee Beef,

one of Australias largest meat processingcompanies, as an in-house welder. As partof his job, Lachlan enjoys a variety ofwork includes pressure welding. One ofhis favourite aspects of work is seeingthe end result when it all comes together,says Lachlan.Through his own experiences, Lachlanopenly encourages school students, whoare interested in a trade or skill basedcareer, to pursue it whilst still at highschool, that way you will be able to findout if you like it and if you do then youalready have some experience, which islooked upon favourably by employers,he says.

Construction Steel WorkcategoryKurt Maier, who represented Australiain the Construction Steel Work category,achieved an impressive 8th in the worldin his competition.Kurt hails from the NSW Riverina,and gained his Certificate III Engineering Fabrication (Trade) through TAFENSW Riverina Institute, Leeton Campus.He works with CB Engineering in WestWyalong, which manufactures qualitysteel vehicle tray bodies and associatedaccessories and undertakes abrasive blasting and powder coating.Kurt has a deep admiration for his bosswho he described to WorldSkills Australiaas a mentor, he is constantly willing to

Welding international bronze medallistLachlan Mayled from New England,NSW. Competing in WorldSkillscompetitions has led me to new andinteresting career pathways. I havelearnt new skills and it has widened myemployment opportunities. I get a lot ofsatisfaction from testing my skills in acompetitive environment.teach me new skills and entrusts me withthe wide variety of new and interestingtasks which come through his workshop,says Kurt. In his opinion, one of the bestthings about his line of work is that factthat he can apply the same principles andmethods he has been taught through hisTAFE course to build many different anduseful things.In the short term Kurt is hoping tocomplete his apprenticeship and will continue to strive to fine tune and develop hisskills. In the longer term, he has ambitionsto start his own business specialising incustom fabrication, precise and qualityconstruction of steelwork which standsout as a quality finished product.

Kurt Maier, Construction Steel Work competitor. Being involved with WorldSkillshas provided me with a once in a lifetime opportunity. I am being given the chanceto compete against the best in the world and am now recognised as one of thebest young tradespeople in my industry, this is something I never imagined couldhappen to me.


WELDING AND CUTTING AUTOMATIONBONUS

FIRST 5 COLLECTORSRECEIVE A FULL SET OFREPLACEMENT FILTERS!

WORLDSKILLS

With 3 Industry Proven Products

KBM

Plate Beveling Machine

KATBAK

Ceramic Weld Backing

KAT

Oscillation Weld Carriage

AMAZING DEAL FROM DONALDSONthe company you already know and trust forquality Fume and Dust collection solutions.Buy an Easy Trunk mobile unitbefore October 31st and receive10% discount and free deliverywithin any Australian capital city.BONUS!! The first 5 units purchased willreceive a full set of replacement filters atno extra cost!! Get in quick.Learn More:

GULLCO INTERNATIONAL PTY. LTD.

1800 FILTER / 02 4350 2000

UNIT 3-42 Trade Street

Tel: + 61 (0) 7 3348 5515

- Lytton - Brisbane - QLD 4178Fax: + 61 (0) 7 3348 5510 e-mail:[email protected]

www.donaldsonfilters.com.au

Supporting WorldSkills

Welding Expert Paul Condran

Lachlan and Kurt have been well supported in their quest to represent Australia by their companies and families, localcommunities and trainers. Lachlan hadgreat mentors such as Paul Condran (seebelow), and former WorldSkills winnersGuy Brooks and Jeremy Gransden. KurtsExpert was John Sharples who works atTAFE NSW Illawarra Institute as the metalfabrication and welding teacher, and hasbeen involved with WorldSkills Australiafor many years.Government, training bodies and thewelding industry including CIGWELD,Blackwoods, Bohler Uddeholm and Pferdin Australia, and The Lincoln Electric Company at the international level, all activelysponsor or support the competitions.WTIA sponsors WorldSkills Australiaat the Regional, National and International levels, and promotes the excellentoutcomes of this great organisation. InJuly Lachlan was assisted by WTIA tocompete in the US Open Weld Trials asa preparation for the Leipzig competitionand you can read about his experiencesthere in the 2012 4th quarter issue ofthis journal. Both young mens trips toGermany were supported by the Institute.Participation in WorldSkills is also promoted internationally by WTIA through itsrole as Australian Member Society of theInternational Institute of Welding (IIW).

Paul Condran works at BlueScope Steelas a Senior Welding/Fabrication Inspector,a position which was offered to him aftercompeting at the WorldSkills InternationalCompetition in Osaka in 1985. In additionto working full time Paul also teaches athis local TAFE in Wollongong.

those who support WorldSkills Australiaand encourage our young tradespeople toreach for the highest levels of achievementin their chosen careers.

You can become involved

Pauls goal is to share his knowledgeand experience to provide competitors thebest chance to succeed and he believes theskills and experiences they obtain throughWorldSkills will be with them forever.

WorldSkills Australias national programme of Regional Competitions isrunning through to December this year.The regional round of competitions isheld biennially with approximately 500Regional Competitions operating acrossthe 30 WorldSkills Australia Regions.Regional Competitions provide youngpeople, working in a trade or skill, withthe opportunity to showcase their passion and talent in over 50 competitioncategories including VETiS. Medallistsfrom this years Regional Competitionsmay then be eligible to compete at the2014 National Competition, where theywill test their skills against Australiasbest trainees and apprentices within theirspecialised skill areas over three excitingdays of competition.Are you interested in competing?Maybe you have an outstanding youngster in your company you would like toencourage? Perhaps you could volunteerto help at the competitions or in training,or could supply sponsorship or materials.

Congratulations to Lachlan Mayled andKurt Maier, and to all the Skillaroos and

Visit www.worldskills.org.au for furtherinformation.

Since 1999, when Paul took on the roleas the Australian Expert in the weldingcategory at the WorldSkills Competition,he has remained the Expert and ChiefJudge at the biennial international eventwith the 2013 International Competitionin Germany taking it to a total of eight.Pauls role as international chief judgeincludes managing the welding competition, which involved 36 judges as wellas the competitors and supporters. Thewelding category received the runnerup Sustainability Award in Leipzig forreducing the overall floor space throughthe introduction of a two shift system.


11

POWER PLANT LIFE ASSESSMENT

New tools for life assessment of aging power plantBackgroundUnder Australian legislation, as part ofAS 3788 Pressure equipment In-serviceinspection, it is a requirement that powergeneration plants undergo at least a Stage1 assessment at 60% design life. A significant number of power plants in thiscountry are aging and have now reached,or passed this point in their design life.The industry has cooperated to sourcenew tools to assist them to conduct thenecessary remaining life assessment.Additionally, in recent years, as a resultof changes in demand and competition,both existing older coal-fired plants andnew combined-cycle gas plants are nowsubject to a variety of different operationaldemands, including two-shift operation,load following and part-load running.A feature of two-shift operation is thatunits that are running at close to designoutput are expected to respond rapidlyto load changes on the system, a resultof the increased utilisation of wind andsolar energy generation. To ensure that thegrid maintains the specified frequency andvoltage, existing and new stations that areunable to accommodate a rapidly changingmarket are more likely to be penalised.Due to these changes in market forces,asset managers need to quantify theincremental costs of cycling generatingunits to ensure profitability and to betterselect, run, and upgrade production units.Furthermore, technical, operations, andmaintenance staff need to understand,plan, and react to the complex natureand interaction of equipment, processes,and failure modes brought on by cycling.As a consequence, at the plant operations level, an asset manager/maintenanceengineer is facing three highly significantpressures: The need to operate plant more flexibly, possibly with faster start-ups;

The need to cycle plant that has notbeen designed for this type of operation;

Dr Warwick Payten, PrincipalResearch Engineer, ANSTO

The need to safely operate ageing plantwith lower maintenance budgets.

factors to be considered during cyclicoperation which are: Increased creep and fatigue damage tocritical high temperature components; Increased capital spend for componentreplacement; Increased routine 0&M cost fromhigher wear and tear; Lower availability due to increase infailure rate and increased outage time; Increased fuel cost from reducedefficiency and non-optimum heat rate.

Estimating damages and costsThe changes to the electricity generationindustry have resulted in a high level ofinterest in the damages and costs associated with non-base load operation. Inthe recent past the vast majority of plantoperators had poor cost allocation systems,to an extent that generally only broad highlevel operation and maintenance (0&M)annual costs were obtainable. Estimatesof damages and costs vary significantly,indicating a poor understanding and differing interpretations between utilities.With the support of an AustralianGovernment Industry Cooperative Innovation Program (ICIP) grant, WTIA ledan Industry Consortium project entitledOptimum welded plant in the heavyengineering and infrastructure industry.This project addressed strategic needs forwelded plant, equipment and products inAustralia in the power generation, defenceshipbuilding and alumina processingindustry sectors.Two of the Milestone projects established for the power generation industryaimed to help provide tools to help thegenerators operate in a more flexibleenvironment. These were: PG 3: Technical Guidance Note onResidual Life Assessment, Plant LifeExtension Methodology and Establishment of a Materials Property Database PG 5: Software for Costing of Start Upsand Shut Downs of Power Station PlantThese projects have provided the generators with information and computerprograms to understand the principal

Figure 1. Secondary stress caused by fast ramp rates at theinlet of an outer casing


Remaining life assessmentHigh temperature pressure equipment hasa finite life that depends on the inherentlimitations of materials, the amount ofconservatism used in design and the natureof operation. A cost effective alternativeto plant replacement is remaining lifeassessment, which if carried out correctly,has the potential to allow plant to be runsafely beyond the original design life often a necessary requirement for ageinginfrastructure. Life assessment is used todetermine the operating time (remaininglife) for the equipment to reach an unsafecondition, based on progressive degradation during operation.The aim of remaining life assessment isto determine the amount of conservatismembodied in the original design life andcalculate the actual remaining life, basedon actual rather than design operatingparameters. The procedures consist ofidentifying the active and potentially activedamage and providing information on: The degree of damage that has occurredto date; The ongoing rate of damage accumulation; and, The degree of damage to cause failure.

Figure 2. Damage interaction diagram showing both timefraction and ductility exhaustion envelopes for the innercasing. Each point is one year. Creep Fatigue Damagecaused by start-ups exceeds the crack initiation envelope.

intermediate-pressure (IP) steam chests,and turbine inlet belts. HP heaters andeconomiser inlet headers are also frequently exposed to similar effects as aresult of rapid cooling by cold feed water.The design codes such as TRD 508,EN 12952-4, API579 and ASME IIINH tend to be very conservative in thesummation of the damage mechanisms.These codes tend to use a linear interaction where the total sum of the damageis less than 1. Ductility procedures, forexample the R5 code, use a linear interaction that adds 1.0. Newer theoreticalmethodologies are being developedand these include both stress modifiedductility exhaustion and strain energyductility exhaustion.The ability therefore to undertake rapidscoping calculations is critical in undertaking the overall sensitivity of a component to changes in operating parameters.A significant barrier for the generatorsin performing remaining life assessment of high temperature componentsis that it involves complex procedures.

Rem-Life softwareAs part of the ICIP Consortium projectPG 5: Software for Costing of Start Upsand Shut Downs of Power Station Plant,in conjunction with a number of generators and the Australian Nuclear Scienceand Technology Organisation (ANSTO),a computer program has been developed- RemLife - along with a guidance noteto help utilities with these complex issuesin a rapidly evolving market.For example Figure 1, shows the secondary stress caused by fast ramp rates atthe steam inlet of an outer casing. Whilethe creep-rupture life of the component

Figure 3. Sensitivity envelopes for the outer casing component,based on number of start-ups, ramp rates, operating temperatureand pressure. Insert shows the position of a number of componentsbased on ramp rates.

exceeds the operation life requirementfor the casing, as a result of fast start-ups,creep-fatigue damage caused by start-upsexceeds the crack initiation envelopebefore the unit has reached its estimatedfuture service life (Figure 2).Using the RemLife program it ispossible to rapidly calculate sensitivityenvelopes for each component, based onnumber of start-ups, ramp rates, operatingtemperature and pressure as illustrated inFigure 3. Costs associated with the current ramp rates is illustrated in Figure 4.This shows that the income generated asa result of the current operational strategyis not sufficient unless the average powerprice achieved by the unit is approximately20% higher than the base price. Based onthese envelopes, the generator can thenbetter manage the equipment and extendthe life in a more flexible environment.

SummaryIn response to aging of power plant inAustralia, and changes in operatingdemands related to market forces, assetmanagers need to quantify the incrementalcosts of cycling generating units to ensureprofitability and to better select, run, andupgrade production units. Furthermore,technical, operations, and maintenancestaff need to understand, plan, and reactto the complex nature and interaction ofequipment, processes, and failure modesbrought on by cycling.Through government support of aWTIA Industry Consortium, the RemLife software was developed to assistin the management of these factors, andhas been successfully implemented inthe Australian power generation industry.

Figure 4. Associated costs of running the outercasing with current ramp rates as a function ofchange in average power price. Yellow planerepresents break even costs.AUSTRALASIAN WELDING JOURNAL VOLUME 58, THIRD QUARTER 2013

13

POWER PLANT LIFE ASSESSMENT

A number of procedures are availablefor performing fitness-for service analyses.They include for example; BS7910, RCCMR, ASME-NH or API579-1/ASMEFFS-1. In specific cases, BS-EN129523, TRD 301, and ASME VIII-2 provideguidance for particular geometries, forexample, branches and nozzles. Themethodologies both in terms of stressintensity and creep-fatigue damage calculations are significantly different. Forexample in ASME III-NH, RCC-MR andAPI579, damage calculations are carriedout using a time-fraction approach, whilethe R5 procedure is based on a ductilityexhaustion methodology.Creep, fatigue and combined creepand fatigue occurs in components thatare stressed at elevated temperatures forlong periods of time. Materials behave in acomplex way when both creep and fatiguemechanisms are present. The mechanismsusually act synergistically to cause premature failure. Creep strains can reducefatigue life, and fatigue strains can reducecreep life. Both primary and secondarystresses are important and while creepmay not take place at the same instanceor time as fatigue the interaction betweenthe two can lead to reduction in life.Cracking of a component is attributedto severe thermal gradients arising fromexcessive steam-to-metal and through-walltemperature differences. These are associated with rapid rates of steam temperaturechange as generally observed during startup, shut-down, and load changes as wellas steady state creep damage at nominaloperating temperatures and loads. Theprincipal components at risk typicallycomprise any thick-walled sections,such as boiler superheater headers, steampipework, valves, high-pressure (HP) and

CORROSION UNDER INSULATION

Corrosion under insulation debunking the myths

Corrosion Under Insulation (CUI) hasbecome a concern for plant operators inthe past 10 years or so. Much inspectioneffort is wasted because the subject is notwell understood, and myths abound. Theintent of this article is to briefly explainand de-bunk some of these myths whileavoiding material which is readily available elsewhere.Unless otherwise stated, discussion willbe on carbon steel piping. Metal coveringswill be referred to as jacketing. Thisarticle will address the following myths:1. CUI will not occur above a limitingtemperature2. There is a lower limit below whichCUI will not occur3. Temperature cycling drives CUI4. Jacketing can be sealed

1. Upper limiting temperatureDry steam within insulation is not implicated in CUI. There is, however, no limitto the general stream temperature abovewhich you can say all the insulation willbe dry. It is the metal temperature whichis critical. Several factors may come intoplay, as shown in the following discussion.A length of pipework has a nominateddesign temperature, a nominated operatingtemperature (normally below the design),and an actual process temperature, usually lower again. The process temperaturedrops as it flows along the pipe, depending on pipe size, flow rate, atmosphericconditions (temperature, wind speed, rain)and the effectiveness of the insulation. Sothe fluid temperature may be considerably below all of the nominal values. Thepipe wall (i.e. metal) temperature will belower again.Water and steam can move throughinsulation even with constant processtemperature. Water flow can cool surfacesin unexpected places and with sufficientflow it may locally reduce the metaltemperature considerably. Differencesof temperature and elevation betweenone location and another can combine todrive steam and condensate through theinsulation. During rain, jacketing willcool well below its usual temperature andincrease the overall driving-force.In process columns the temperatureis held hot at the bottom, cool at the top.Insulation is supported on rings which,until recently, were welded directly onto

the shell. CUI is a common occurrencewhere water can pool immediately abovethese rings, stiffeners and other attachments. Severe corrosion, however, wasfound in a region operating at well over130C immediately under an insulationsupport ring.It appears that water above the ringflows downwards immediately behind thejacketing, until it reaches the ring. Here itpools, is soaked back into the insulation,boils against the shell, and the steam flowsup the column adjacent to the shell. Belowthe ring, water also flows down behindthe jacketing and boils further down, andthe steam flows adjacent to the shell backup to the ring. The water above the ringkeeps the ring cool, and the rising steamcondenses under the ring and corrodesthe shell. This is the best explanationoffered for what was found - it may notbe quite correct.Within the insulation the temperaturedrops between the pipe wall and thejacketing. Jacketing temperature is typically below 60C. The outer part of theinsulation maybe half is between 60and 100C. No matter how high the headertemperature, any drain or pipe supportwithin this region, or any branch pipepassing through it with insufficient flowto maintain temperature, can corrode.A 450 psi superheated steam headerat over 300C corroded through a drainnipple just an inch below the header. Asolution is to install a sleeve, as part of thejacketing, around the drain nipple with asmall annular gap to keep the insulationaway from the nipple.This will not occur on a short vent offthe top of a steam line. Water that condenses in the vent will drain back to theheader, and the vent will remain hot andfull of steam at saturation temperature. Ifthe vent is long, however, and particularlyif there is a horizontal section, there maybe sufficient water held up to allow thetemperature locally to drop into the CUIrange.

2. Lower limiting temperatureBelow about 5C corrosion will not occurto any great extent. Again, however, it isthe actual temperature that applies, not thedesign or operating temperature.The major issue is that valve yokesand other components (vents, drains etc.)


Roger GriffithsPrincipal Mechanical EngineerBP Refinery (Bulwer Island) Pty Ltdproject away from the main header, andare warmer. Condensation will alwaysoccur, and such components are constantlywet. The most significant corrosion I haveseen is on valve gland follower eye-boltsand nuts. If these fail the gland will leak.

3. Temperature cyclingTemperature cycling is said to accelerateCUI. Boiling and condensing within insulation may contribute to transporting waterand salts within the insulation: when hot,steam will tend to fill the insulating layers(though will not directly carry salts), andthen condense in places that otherwise mayhave remained dry and the condensatemay then pick up salts and drain them to alow-point. This effect, however, is believedto be small, and cannot be measured inan operating plant.The issue is generally more mundane: ifthe nominal design or operating temperature is regarded as providing sufficient protection no coating, or the wrong coating,may be selected. Corrosion then occurswhenever the equipment is at a susceptibletemperature. Furthermore, some coatingsmay survive at high temperature whendry, but not at a cooler temperature wheneffectively immersed in water.Temperatures vary for many reasons.Inspectors must take into account thatshutting a valve will imply that all the pipedownstream, and some length upstream,will go cold and corrode. Bypass lines,start-up lines and others are all susceptible.

4. Sealing of jacketingGriffiths Law of Sealing Insulation is:You can seal water in, but you cannotseal it out.

Stop magnetic arc blowSolutions for all magnetic arc blow problemsAll welding scenarios coveredFast and effective solutionUsed by welding companies worldwideTraining and on-site supportBuy, hire, sub-contract or lease

PRODUCT RANGE

www.streamlinecreative.com.au

DKPW - Demagnetizers kit for pipe welders | ZM100A - Zeromag demagnetizer | ZM100A-30 - High power Zeromag demagnetizerZM150 - ZM100A add-on for pipe end or joint degauss | ZMCC - Clam coils fast deployment of demagnetizing cableZMBOB - Pipe end bobbins | MF300H+ - Magmeter for measurement in weld joint | MF300F+ - Ferrite meter

NDT EQUIPMENT SALES UNIT 23, 58 BOX ROAD TAREN POINT NSW 2229TEL: (61-2) 9524-0558 FAX: (61-2) 9524-0560 Email: [email protected] Web: www.ndt.com.auAWJ - Quarter Page Vertical-ESH_cl2.pdf 1 8/23/2013 9:01:53 AM

A very small hole allows water in, and it will accumulate.Sealing insulation completely is, in practice, impossible with acomplex structure. I have often observed gaps that have openedup within days of being thoroughly sealed with silicone.For hot equipment the sections of jacketing have to slide overeach other as the equipment heats up and expand as it comes onstream. Jacketing ripples in the wind, process columns sway.I recently visited a plant in Germany where they claimed thejacketing on a critical vessel was fully sealed. This was a largedrum, with very few protrusions through the insulation, operating at ambient temperature and insulated for fire protection.In two minutes I was able to show them at least half a dozenplaces where rain would get in. The silicone which had onlyrecently been applied had already pulled away from jointsand penetrations.Drilling holes along the bottom of metal jacketing mayhelp by allowing water to drain. If insulation fibres protrude,however, water could be drawn in. The holes need to be belledoutwards to form drip-stops. This can be achieved by drillingwith a self-drilling roofing screw operated through a mandrel(which could be made from a cotton reel). The screw is drilledinto the jacketing, the threaded part of the screw penetrates thejacketing until the mandrel comes up against the jacketing,continuing to rotate the screw then bells out the hole.C

M

Y

CM

MY

CY

CMY

Training CoursesFitness-for-Service Assessmentto Prolong Asset Life forPressurised Plant EquipmentQuest Integrity Group is offering training coursesthat cover the basis for assessment of pressureplant equipment for continued service and lifeevaluation in accordance with the API 579-1/ASMEFFS-1 standards.These courses are for inspectors, plant engineersand engineering managers that are involved in theoperation and maintenance of plant facilities andare designed to help make decisions on whether torun, repair or replace critical pressure equipment.

K

ConclusionFor any inspection to be effective it is important that it beproperly focussed, and a good understanding of the potentialprocesses in action, such as CUI, is essential for this. Misinformation or myth can divert attention away from critical troublespots, generating significant potential issues in plant and riskmanagement.

Perth, AustraliaSeptember 17-18, 2013

Brisbane, AustraliaOctober 23-24, 2013

To find out more or register now:www.QuestIntegrity.com/FFSCourses


15

The Australian Steel Institute (ASI) Boardrecently approved work to commence ona fabrication code of practice named SteelConstruction Code of Practice to ensurethat all structural steelwork producedor used in Australia that is designed tothe general structural and bridge designstandards AS 4100 and AS/NZS 5100,regardless of country of origin, meetsor exceeds current Australian Standards.This Code of Practice is intended to be aforerunner to an Australian Standard forsteel fabrication, sadly lacking in thiscountry. The Australian Code of Practicewill be based on the UK model (whichcalls up standard EN 1090) whereby anengineer assesses the complexity and riskof all structures to ensure compliancerequirements match that risk.The scheme will be discussed on theFabricators Day, Tuesday 10 September,at the 2013 ASI Australian Steel Convention being held at the Gold Coast. At theFabricators Day morning session, DrRoger Pope (who is active in the administration of the UK scheme for the BritishConstructional Steelwork Association)will provide expert knowledge aroundthe nature and scope of how the UKscheme has contributed to improving thecompliance of fabricated steel there. Allstructural steel fabricators are welcome toattend and there are a number of optionsranging from full conference attendanceto the Fabricators Day to just the freeFabricators Forum in the afternoon of the10th. For further details visit http://steel.org.au or email David Ryan on [email protected]

The UK schemeThe UK scheme is a quality compliance andcertification system for supply, fabricationand erection of structural steelwork basedon the principles of the European systemto EN 1090 (which exists within a regulatory system including CE marking). TheUK scheme includes a complete range ofstructural steel, casting, forging, stainlessand wire product and fabrication groups.A proposal is being considered to implement a similar scheme in Australia andthis will be the subject of discussion withAustralian steel fabricators at the forum.The draft structure of the AustralianSteel Construction Code of Practice is: 1.Scope 2.Normative referenced Standards 3.Terms and definitions 4.Specifications and documentation 5.Materials 6.Preparation, assembly and fabrication 7.Welding

8.Mechanical Fastening 9.Surface treatment and corrosion protection10.Erection11.Geometrical tolerances12.Inspection and testing13.Correction and non-conformities14.Site modifications and modificationof existing structures

Purpose of the proposedAustralian complianceschemeThe Australian construction industry needsto have project cost balanced against abasic requirement that steel products aremanufactured, installed and operate safely.To achieve this, all products and fabricatedassemblies must meet the full requirements of the relevant Australian Standardsspecified, regardless of country of origin.As with many construction products,the current regime of self-inspection andcertification for structural steelwork (selfcertification) demonstrably does not work.ASI believes that Australia needs a betterpurpose-built compliance regime in whichto operate. The National Structural SteelCompliance and Certification Schemeseeks to provide this balance betweenquality, safety and cost.

BackgroundIn recent years Australia has becomeexposed to the full ramifications of aglobal market in construction productsupply. Traders are sourcing steel and steelcomponents on price from anywhere inthe world market. The lack of rigour incurrent Australian compliance regimes(compared with our equivalents overseaslike the USA, Canada, UK etc.) coveringthe supply of structural steel (along withmany other construction products), hasled to an unacceptable degree of unsuitable and often faulty steelwork for majordevelopment projects in Australia. Thisissue is compounded as supply chainsbecome ever more globalised.In general the engineering community,in particular designers, are no longer contracted to do site inspections and are predominantly paid only for the base design.ASI is aware engineers can also be underpressure to substitute foreign materials andmaterial standards where there is a costsaving to the client. This concerns building surveyors and inspectors who do nothave the engineering expertise or knowledge to identify steel defects or checkwhether the steel supplied is compliant.


Building Importance Level* 1, 2, 3, 4Service Category SC1, SC2Production Category PC1, PCsConstruction CategoryCC1: Simple Structure: lowconsequenceCC2a: Medium structure; moderateconsequenceCC2b: Medium structure: moderateconsquenceCC3: More complex; higher risk

Increasing compliancerequirements andlevel of verification

STEEL CONSTRUCTION CODE OF PRACTICE

National Structural Steel Compliance & Certification Scheme

CC4: Most complex: highest risk

Figure 1. Schematic showing theassessment of Construction Categoryin the planned Australian SteelConstruction Code of Practice* To be based on the Building Code of Australiaand AS/NZS 1170.0

Builders and project managers alsooften do not have the skills or knowledgeto understand compliance at a materialor fabrication levels, and often drive thesubstitution of non-compliant steelworkbased essentially on cost considerationsalone. The ASI has worked with prominentbuilders on compliance specificationsand in this process they have indicatedsupport for a national scheme, citing thesignificant cost savings to the communityfrom a shared resource such as this.The implementation of a system thatrequires the stakeholders in the construction chain to fulfil their complianceresponsibilities within their scope will begood for Australia, resulting in: cost savings from the use of sharedknowledge; productivity increases through minimising the need for rework and repairover the lifecycle of the project; and, reduction in risk consistent with theintent of the relevant Work, Health andSafety Acts (for further informationon this refer the ASI website http://steel.org.au/key-issues/compliance/whs-2011/ and in particular the Q&Apaper from Qld Workplace Health andSafety WHSQ directly linking the Actwith compliance)A functional Compliance and Certification Scheme will also align Australiawith our counterparts overseas, and in theglobalised economy, ensure that we do notbecome a dumping ground for productunable to meet the regulated complianceregimes of the major international markets.For further information contact ASIEmail [email protected], Phone:02 9931 6666 or visit http://steel.org.au

Introduction

Ultrasonic weld inspection techniques suchas Phased Array (PA) and Time of FlightDiffraction (TOFD) are rapidly beingadopted both in Australia and the rest of theworld. Since its introduction more than 20years ago, PA has gone from a clumsy andsometimes useful technique, to a highlysophisticated, reliable and valuable toolthat can be used to check the simplest ofwelds to the most complex applications.It is no longer bleeding edge. Theequipment has become more powerful,easier to use and lower cost. NDT serviceproviders now have trained and experienced PA technicians and equipmentavailable to cover a range of situations.They can also provide support servicesfrom training to analysis.Here we will briefly explain the technology and some applications

Phased Array weld inspectionUltrasonic weld inspection sends a soundbeam into the part at an angle and receivesa reflection from any discontinuity. Thestandards usually prescribe inspection atangles of 45, 60 and 70. These, whencombined with the beam spread, providegood coverage.In conventional ultrasonics threeseparate scans are usually performed. Thetechnician would interpret each waveformor A-scan (see Figure 1) to determine ifthere was something to report.

weld inspection

With PA, we can generate each of thethree angles electronically, and all theangles in between (Figure 2), then combine each beam into a composite picturecalled the sector scan (Figure 3), where thecolour reflects the size of the reflection.We can immediately see that one scaninstead of three is all that is needed toachieve the same result as with conventionalultrasonics. Suspicious areas are moreobvious, so detection rates are improved.This image with a weld overlay makesit easier to see the size, location and typeof indication. By recording this at regularintervals along the weld (e.g. 1 mm, withan encoder), the spread of an indicationcan be assessed.Therefore, unlike conventional ultrasonics, this process provides a recordof the inspection, greatly reducing thereliance on the operator, and providingthe ability to carry out post-inspectionanalysis and evaluation.

Time of Flight DiffractionTOFD is a technique of sending a singlebeam through the body of the weld. Thesound will create internal vibration in adiscontinuity that in turn will emit soundwaves in all directions from its extremities.These sound wave show up at differenttimes and phases which can be used todefine the depth and height of the defect(see Figure 5).The advantages of this include a shorterpreparation time, higher sensitivity to

volumetric and planar defects, and thecapability to determine the length andheight of a defect. It is also a code compliant alternative to radiographic testing.TOFD is becoming an important technique, one that is simple to set up and runbut now without the need for expensiveand inflexible display equipment. With thedevelopment of PA gauges it has been arelatively simple step to add TOFD capability using the latest image technologies.So the availability at little extra cost hasmade TOFD more accessibleThe key advantage of TOFD is that it isindependent of the orientation of the objector weld being examined (see Figure 6).Indications, however, can be ambivalent,and it has some limitations near the capand the root, so it is often combined withPA to provide best coverage and analysis.

Combining Phased Array andTime of Flight DiffractionIn many situations, both PA and TOFDare used together to achieve code compliance, where the alternative is radiography(see Figure 7).

Comparison with radiographyThere have been many articles and reportscomparing PA with radiography. Themajor international standardsincludingASME and APIallow PA inspection asan alternative to radiography. Advantagesof PA are that it does not have the safetyand processing time issues of radiography, so is attractive as a real time qualitycontrol tool.Additionally, the height measuringcapabilities are useful during in-serviceinspection, where life prediction fromdefect sizes is important.

Figure 1. Phased array

Figure 2. Phased array beam paths toweld

Richard Nowak,Product Specialist Non Destructive Test,Olympus Australia

Equipment progress

Figure 3. Sector scan (Lack of side wallfusion)

There is currently very strong developmentin equipment and support systems for PAand TOFD. In the gauges the trend is tosimpler, more intuitive interfaces, easieron-gauge analysis, cleaner signals andenvironmental robustness. As an example,Olympus has just released the OmniScanSX which allows simple applications tobe carried out at lower cost, without compromising performance or data.There is continuing growth in the development of training materials, case studies,planning software and analysis software to


17

U LT R A S O N I C W E L D I N S P ECT I O N

Developments in ultrasonic

U LT R A S O N I C W E L D I N S P ECT I O N

Figure 4. Phased array C-scan display

support PA inspection. In addition, training providers are offering more frequentcourses, and the growth in the numbersof experienced personnel is helping newoperators themselves gain experience.With general weld testing now welldefined, researchers are developing techniques and instruments for analysis ofjoints in a diverse range of materials including thin pipes, austenitic, clad pipes andhigh-density polyethylene (HDPE) pipes.

Typical applicationsThin welds

Figure 5. Time of Flight Diffraction

Figure 6. TOFD on weld

Thin circumferential welds 10 mm to50 mm, 100 mm diameter to flat are theeasiest to cover using standard equipment.Welds in small diameter pipes 2-3mm to 10 mm and diameters 20-100 mm such as those found in boiler tubes, provide some technical obstacles. Speciallyfocussed, very low profile probes havebeen developed to enable analysis of thesewelds, culminating in the development ofthe Cobra scanner.

A scanner utilising multiple probes,or making several passes with mergingsoftware, is usually used for this.

Austenitic steelsAustenitic steels are particularly difficultbecause the enlarged grain size attenuatesthe signal.There is a hierarchy of solutionsdepending on the material, the weldprocess, geometry, and rejection criteria.Recently, dual matrix array probes havebeen developed that allow much betterpenetration through large grains. A lot yetneeds to be learned of their application.

Pipes with CRA cladding

Thick welds

Corrosion Resistant Alloy (CRA) coating used on many pipes in the oil andgas industry presents a few challenges.The coating is very difficult to penetratewith sound or with radiography.Some NDT service companies havedeveloped techniques to overcome this,sometimes using direct PA angle beams(i.e. not reflected off the back wall), coupled with TOFD and sometimes probeson the cap (if the cap is reasonably flat).

Thick welds up to about 70 mm or morerequire several beams to cover the body,and are often augmented with TOFD.

Long pipelines for oil and gas are oftentested with a unit such as the PipeWizard.

Pipelines

Figure 7. Multi Group Phased Array with TOFD


The 7th Asia Pacific International Instituteof Welding (IIW) International Congressentitled Recent Development in Weldingand Joining Technologies was hosted inJuly by the Singapore Welding Society(SWS). This followed the successful 6thAsia Pacific Congress which was presentedby WTIA in Cairns, Queensland in 2011and the 2009 Singapore IIW AnnualAssembly hosted by the SWS.The Opening Ceremony started with theWelcome message by Ang Chee Pheng,Chairman of the Organizing Committeeand Opening Address by Sze Thiam Siong,SWS President.With nearly 200 people attendingfrom 25 different countries, 12 of themwithin the Asia Pacific region, and over100 papers presented, the 2013 SingaporeCongress delivered excellent outcomes andachieved the goals of an IIW InternationalCongress, namely to: Assist countries in the region to utilise appropriate welding and joiningtechnology to improve the quality oflife of their people; Expose industry delegates from thehost and surrounding countries withinthe region to the work of the IIW andthe international community, throughthe participation of, and interactionwith, the experts who attend; Work with the host and regionalcountries to identify their needs and

International representatives from IIW gather around Organising CommitteeChairman Mr Ang Chee Pheng during the IIW International Congress in Singaporeto produce IIW-supported programmesto help meet those needs; Encourage international governmentorganizations such as UNIDO tobecome formally involved in IIWInternational Congresses and subsequent programmes; Provide an interactive and encouragingforum for authors from less developedcountries in the region to presentpapers about research and industryin their respective countries; Facilitate trade relationships, to identify supply and demand needs andto establish working relationshipsbetween countries in the variousregions of the world; Provide recognition for the host country and for those in the neighbouringregion for their achievements andinnovations in welding and joining.WTIA Councillor Rob West (AlcoaGlobal Primary Products) and CEOChris Smallbone were members of theInternational Advisory Committee supporting the Congress, and Chris attendedthe Congress to participate in the openingceremony and deliver a Keynote Addresson the IIW White Paper.The Jaeger Lecture on the topic ofWHS reform was presented by Er. HoSiong Hin, a Mechanical Engineering

This uses a combination of phased arrayand TOFD, but the phased array is doneusing a zone technique, where the beamis focused on a small part of the weld ata time. A strip chart of the results makesfor easy analysis.The technique is very expensive toset up, requiring test holes at each focuspoint for calibration, but once running isvery efficient.

Glen Allan, WTIA OzWeld Technology Support Centres Network Manager,presented a paper on Changes in WHSLegislation and Latest Revision of WTIATechnical Note 7, and Chris also deliveredtwo further papers, one co-authored withRob West and Stan Ambrose on Developments in Pressure Vessel Technology,Standards and Compliance and the secondco-authored with Stan Ambrose and DavidBarnett, Chairman of the AustralianInstitute for the Certification of Inspection Personnel (AICIP) on Successes andFuture Challenges in the Certification ofPersonnel for In-Service PE Inspection.Meetings were also held with IIW Secretariat, and other IIW members, such asProf Gary Marquis, Chairman of the IIWTechnical Management Board, attendingthe Congress.Six exhibition booths were displayedduring the 3-day Congress period. Aninteresting International Welder Competition was held using the LincolnsVirtual Welding Machine. Among theparticipants representing more than 10countries, Australian Welder Glen Allenwas the champion.probably the dominant standard currentlybeing applied in America and Asia, andfor many large projects here.The alternative for many is to qualifytheir procedure as being equivalent to therelevant Australian Standards, which addstime and money.In spite of this, phased array has a majorpresence in Australian industry.To simplify and provide the option ofPA to all, the industry the users needto press for inclusion of PA in the Australian Standards.

HDPE weldsPA zero degree probes are used for electrofusion welds on HDPE pipes. TOFD andPA are both being tried on HDPE buttwelds. TOFD looks very promising inthis area.There is a lack of standards on HDPEwelds, so each user must decide their ownacceptance criteria.

graduate from the University of Auckland,New Zealand and Divisional Director,Occupational Safety and Health Divisionof the Singapore Ministry of Manpower.

Weldrover motorised scanner

StandardsThe major factor limiting the uptake ofPA in Australia is that it is not includedin the Australian Standards. ASME is

SummaryPhased array ultrasonics is a fast, safemeans of testing a wide variety of welds.It is a cost and time effective solution forproduction situations, and for in-servicetesting.


19

I I W C on g ress S in g apore

Regionboosted bySingaporesuccess

DIGITAL RADIOGRAPHY OF SHIPS

How does NDT

keep ships afloat?

Those of you who have ever taken a cruise have probably wonderedhow such a huge vessel manages to stay safely afloat when crossinglarge bodies of water. Few are aware of the major role thatNDTweld inspectionplays in ensuring the vessels safety.

The ship building structure processincludes two main stages: production,and NDT inspection of the ships countless welds. Both of these processes arevery time consuming. With the aim offacilitating the production process, someshipyards have transferred to laser beamwelding. In some cases, this systemenables the welding of plates of up to 30meters at one time.Thus, the welding time has been effectively shortened. But what can be done tofacilitate the NDT inspection process?Conventional radiographic testing methodshave several serious drawbacks. Due to thehigh radiation when conventional methodsare used, NDT testing is conducted duringnight shifts, doubling labor costs. With filmX-ray, re-shoots are often required anddevelopment time is lengthy, making theassessment process slow and complicated.When using conventional X-ray methods,cables must be stretched over extremelylarge areas and reach almost inaccessiblelocations. Cables are often cut unintentionally, due to the steel plates sharp edges.

In order to overcome all of the obstacles described above, leading shipyardssearched for an all-in-one NDT solution.They discovered the VidiscoportableDigital Radiography (DR) systems, whichsignificantly expedite the NDT inspection process in shipyards and resolve theprevalent NDT problems. Bottom line,these systems save the shipyard significantamounts of time and money.The portable DR systems effectivelyeliminate bottlenecks in the NDT inspection process and save precious time inshipyard production. The digital detector array (DDA) imagers used in DR arehighly sensitive, thus enabling the use ofX-ray sources that emit very low doses(e.g. pulsed X-ray sources). Safety zonesare reduced. As there is a minimal risk,NDT weld inspections can take placeduring day shifts alongside the regularproduction work, saving both time andmoney. In addition, portable DR systemsprovide top-quality images on a laptopscreen within seconds and upon request,thus eliminating unnecessary waits,reducing the analysis time and enablingimmediate action.These X-ray systems are truly portableand lightweight, which means that theycan easily be carried to and installed inhard-to-reach, elevated spots even in theroughest conditions. Due to the fact thatthey are powered by batteries and equippedwith wireless modules, these portable DRsystems operate without tangled wiresand cables.

Rachel Lieberman

Figure 1. Laser beam welding of shippanelsture enables the system to take top-qualityimages that it produced, and stitch themtogether automatically based on the pixellevel throughout the image. The softwarealso provides excellent measurement capabilities, enhancing minute defects. Largeweld sections can be viewed at once onscreen with great detail.All of these features combine inVidiscos range of portable digital X-raysystems to present an ideal NDT solutionbased on leading DR technology for bothsmall and large shipyards.This article was first presented byVidisco NDT expert Ron Pincu at theBINDT/MT Exhibition 2011 and is provided by NDT Equipment Sales, AustralianAgent for Vidisco www.ndt.com.au

The shipyard industry is required tomeet various international standards inthe area of NDT inspection. Such certification is provided to X-ray equipmentmanufacturers that support these standards.

Figure 2. Portable digital radiographsystem on a hull section

Vidiscos portable DR systemseffectively resolve many of the difficultiesencountered in shipyard NDT usingconventional radiography. Additionally,they are equipped with the companysproprietary XBitPro software, whichcontains various enhancement tools suchas stitching and advanced measurementcapabilities. The softwares stitching fea-


Figure 3. Vidiscoportable DigitalRadiography (DR) system

Is NDT Working for You?

The Australian Institute for the Certification ofInspection Personnel (AICIP), formed by, andfor, the Australian Pressure Equipment industry,supports the regulatory and in-service inspectionneeds of the pressure equipment industry throughthe on-going certification of inspection personnel,and the promotion of quality plant inspection andmaintenance.Since formation in 1997, AICIP has certifiedthe competence of over 530 in-service inspectorsof pressure equipment supporting a vast range ofindustries Australia-wide. Listing of these inspectorscan be found on the public register on the AICIPwebsite www.aicip.org.au.

AGM and Panel ofExaminersThe 17th Annual GeneralMeeting of AICIP was heldon 29 May 2013. The meeting overviewed the significantpositive progress made byAICIP in 2012 and acceptedthe Financial Statements forthat year. As with previousyears AICIP had been very successful as shown by the growthin the number of examinees.Peter Eckberg, representingAICIP Member the Compressed Air Association ofAustralasia (CAAA), waselected as the incoming Chairman, while thanks were givento David Barnett who hadcompleted his term of officeas Chairman. Rob Svensk,representing the AustralasianInstitute of Engineer SurveyorsInc., was elected Vice-chairman, andWTIA CEO ChrisSmallbone was re-elected asSecretary/Treasurer and PublicOfficer.The AICIP Panel of Examiners met in August to continue their excellent work,ensuring that examinationsare maintained at a high levelof integrity and relevance toAustralian industry needs. The

Panel is open to all feedback,from candidates and industry,and can be contacted via thewebsite of Secretariat.

ATTAR can reduce your riskNDT Consulting/Level 3 ServicesWritten Practices & ProceduresStandard and Report InterpretationAudit Preparation; Supplier AuditsSpecialist Technique DevelopmentProficiency Testing

NDT TrainingIntro, Basic, Advanced, Practical-Only TrainingCustomized & Private CoursesAINDT & BINDT (PCN) Examinations, RenewalsIn-house Schemes e.g. SNT-TC-1A

Demonstrate ComplianceOptimise ProceduresATTAR - NDT Services that Workwww.attar.com.au

Job knowledgePressure vessel inspectorsshould be aware that someadvanced NDT techniquesrequire a high degree of analysis, and this must be performedby competent people.A vessel in a large processplant was recently inspectedusing phased array. The vesselwas subject to a high fatigueloading, and the welds wereknown to contain flaws fromconstruction. The report indicated that the flaws had grownto a size at which continuedoperation was not advisable.As a result steps were takento take the vessel off-line forfurther inspection and repair.The findings were questioned and re-evaluated: there-evaluation showed that thesize calculations were faultyand the defects were in factstill acceptable. The shut-downwas therefore terminated andthe vessel returned to stream.The brief period of shutdown, however, cost the operator a significant sum in themillions in lost production.

Had the shut-down been terminated just one day later thecost would have been five toeight times as much, as onceexposed to air the vessel wouldhave had to have been emptiedof catalyst and re-loaded.

Renewal ofcertificationCongratulations to the following Inspectors whose certification was reviewed and renewedfor a further period.

ISI 5-year renewalsSteven Storey, NTRobert Edgar, NSWDarren Ross, NSWSteven Bond, QldRandall Cain, QldTerry Hewson, QldDean Raphael, QldBruce McEwan, SAMark Leahy, VicAnthony Buhagiar, WACollin Maloney, WABenjamin Townsend, WAAlan Williams, WAMartin Wolmarans, WA

ISI 15-year renewalJohn Leijser, WA

2014 examinationscheduleExaminations for ISI paper A& B Theory, ISI paper E Practical, SISI papers C & D Theory and ISI/SISI PaperF(10/20 year Re-certification)are expected to be held inMarch and September 2014.Venues typically includeBrisbane, Sydney, Darwin,Melbourne, Adelaide andPerth, according to applicantinterest, and special centrescan be arranged by agreement.For further informationplease go to the AICIP websiteor contact Michelle Orr at theWTIA AICIP Secretariat Tel:02 8748 0119 or email [email protected] AICIP website www.aicip.org.au provides a feedback and contact update facility for inspectors who mayhave recently changed addressor contact details.


21

aicip news

news

When Non Destructive Testing is notmanaged properly, your business is at risk.

OZWELD SCHOOL OF WELDING TECHNOLOGY

OzWeld Schoolof WeldingTechnologyInternationallyaccreditedtrainingThe WTIA OzWeld School ofWelding Technology (SWT), anInternational Institute of Welding(IIW) Approved Training Body (ATB) holds IIW qualification andcertification training in centres around the country. Many of thepeople trained have gone on to sit examinations to achieve IIWand WTIA qualifications and certifications. The latest resultsare listed on page 28. In-house training can also be deliveredfor companies in each State.Enquire now about how training leading to qualification andcertification can enhance your career prospects and support thedevelopment of the Australian welding industry.Contact Training Administrators Kim Griffiths ([email protected] Tel: 02 8748 0108 or Shirley Delarue ([email protected] Tel: 02 8748 0109) or visit the new training areaon our website www.wtia.com.au for further information.

Contact our customer service team members Kim Griffiths(left) and Shirley Delarue now to discuss your training andcareer needsThe Institute has put significant effort into compiling thetraining resources for each IWSD module and in particular, hasused the services of top people in their fields to both prepareresources and lecture the training modules.Such experts include Mr Arun Syam (Tubular DevelopmentManager, OneSteel), Mr Ken Watson (Executive Director,National Association of Steel Framed Housing), Prof Xiao-LingZhao (Department of Civil Engineering, Monash University),Dr Fidelis Mashiri (School of Computing, Engineering andMathematics University of Western Sydney) and Mr Peter Ford(Principal, MCA Australia).

International Welded Structures DesignerThe IIW International Welded Structures Designer (IWSD)qualification programme is intended to produce competent andknowledgeable design-related personnel who can add value totheir organisations by designing welded structures that: Are capable of being fabricated, inspected, transported andplaced in service economically; Have the required reliability, integrity and safety; and, Perform their intended function.So the objective is to train and qualify design and engineeringpersonnel who will be more competent to design, specify andcontract the manufacture of components, and give assuranceof conformity and commissioning of welded components foroptimum performance.Design for welded structures forms the very foundation ofsuccessful fabrication and productivity. Such design capabilityenhances a countrys ability to compete for fabrication projects,and Australian companies are keen to keep this capability onshore, to enable them to compete in both the domestic andinternational markets. The need for training and qualificationof design personnel has been acknowledged, and is discussedfurther in the article on page 24.

IWSD training programmeThe IIW IWSD qualification consists of two levels: Standardand Comprehensive.The WTIA initiated training for the IIW IWSD Standard Levelduring 2012 and the Qualification and Certification Board isplanning to hold the first set of examination in November 2013.


IIW International Welded Structures Designer course expertsfrom left Ken Watson, Xiao-Ling Zhao, Fidelis Mashiri, PeterFord and Arun SyamThe WTIA OzWld School of Welding Technology willcommence delivering the training modules for IIW IWSDComprehensive level in 2013, with the first examinations forIWSD C in May 2014.The first course is planned for Melbourne, Victoria on thefollowing dates, with the venue to be advised on registration.SWT 66 Welding Technology for Design, 10-12 December 2013SWT 67 Properties of Materials and Failure Mechanisms,1-3 October 2013SWT 68 Design of Welded Structures, 22-24 October 2013SWT 69 Fabrication, Costs, Quality and Inspection, 19-21November 2013SWT 70 Design of Welded Joints, 3-5 December 2013SWT 71 Design of Welded Plate Structures, 4-6 February 2014SWT 72 Design for Purpose of Welded Structures, 18-20February 2014

Course content and attendanceThe comprehensive training programme is structured to covermodern welding technology used in industry, materials andtheir behaviour when subjected to static and dynamic load-

International expert Ing.Henk Bodt IWE from theNetherlands delivereda recent WTIA MemberWebinar

European standards andwelding coordinationpersonnelOver 50 WTIA members benefited recentlyfrom a WTIA Webinar delivered by international expert Ing. Henk Bodt IWE fromthe Netherlands, on the topic CPD, CPRand EN 1090: The consequences. Mr Bodt

is President Elect of the European WeldingFederation, a member of IIW and active instandards development through the ComitEuropenne de Normalisation (CEN), ISOand Dutch standards committees.He spoke of the European Construction Products Regulation (CPR) whichreplaced the Directive in 2011 and whichrequires all structural steel and aluminiumproducts to be CE marked to improvefree trade across the European EconomicArea (EEA), consisting of the 27 memberstates of the EU and European Free TradeAssociation countries Iceland, Liechtenstein and Norway. The CE marking atteststhe verification by a manufacturer thatthese products meet EU safety, health orenvironmental requirements.EN 1090 Execution of Steel and Aluminium Structures is a harmonised supporting standard that sets the requirementsfor conformity assessment of steel andaluminium structural components. For amanufacturer to be able to CE mark theirstructural products, they shall establish,document and maintain a factory production control (FPC) system to ensure thatproducts placed on the market conform tothe declared performance characteristics.A typical FPC system consists ofregular maintenance and calibration ofequipment, frequent checking to ensureproduct conformity and the managementof non-conforming products. FPC is allabout producing products with the samedeclared characteristics time and timeagain.When the manufacturer is ISO 9001or ISO 3834 certified, parts covered byISO 9001 or ISO 3834 checklists maybe excluded upon decision of the Notified Body. To maintain the certification,the companys FPC system is subject toregular surveillance audits.EN 1090 specifies inspection criteria,calling on qualified personnel for weldinginspection. These people must have generalknowledge of welding and comprehensiveknowledge in the field of inspection.Inspection can be performed directly bythe Welding Coordinator, or by separatewelding inspectors, depending on the; Variety and complexity of the products; Size and number of workshops; and, Relevance

AWJ 2013 Issue 3.pdf

Documents

Transcript of AWJ 2013 Issue 3.pdf