ASME NDT Familiarity Training

CHAPTER

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20.1 INTRODUCTION The purpose of this chapter is to provide users of the ASME

Boiler and Pressure Vessel Code Section V [1] an insight into thesignificant Section V requirements, NDE methods, and NDEmethodology, as well as the relation of Section V to other ASMEbook sections and to the use of the American Society for TestingMaterials (ASTM) Standards [2]. The information provided inthis chapter is based on the 2007 edition of Section V with 2007addenda, dated July 1, 2007.

The charter and scope for the Subcommittee for Section V(SCV) is to develop and maintain Code rules for NDE methodolo-gy and equipment involved in surface and volumetric testingmethods. These test methods are used for the detection and sizingof defects, discontinuities, and flaws in materials and weldmentsduring the manufacture, fabrication, and construction of parts,components, and vessels in accordance with the ASME Boilerand Pressure Vessel Code and other ASME Codes; for example,B31.1 for Power Piping [3].

SCV members consist of representatives from manufacturers,insurance companies, architectural engineering companies,research organizations, utilities, consulting firms, and the NationalBoard of Boiler and Pressure Vessel Inspectors. All additions,revisions, inquires, and Code Cases relating to Section V arereviewed and approved by the SCV before being presented to theMain Committee for review and approval for adoption.

20.2 ORGANIZATION OF SECTION V It is important for users to become familiar with the organiza-

tion of Section V. The book is divided into two basic subsections.Subsection A of Section V contains Articles 1 through 17, includ-ing Mandatory and Nonmandatory appendices that address generalrequirements, test methods, and specific Code requirements.Subsection B of Section V contains the ASTM Standards (Articles22 through 31) that have been adopted by the Code.

Following Subsections A and B is Mandatory Appendix I, whichprovides guidance and directions for the Mandatory Submittal of

Technical Inquiries to the Boiler and Pressure Vessel Committeeand is therefore of utmost importance to users. Before submittingan inquiry to SCV, users should carefully consider their specificproblem and select the proper category from the following listing inthis Mandatory Appendix:

(1) a proposed revision to present Code rule(s); (2) a new or additional Code rule(s); (3) a Code Case; and (4) a Code Interpretation. The SCV receives many inquries that do not provide the

required details. Unfortunately, this lack of specificity only delaysthe review process. Inquiries that request a Code Interpretationmust be composed as brief and precise questions that can beanswered by a simple yes or no. On occasion, requests forCode Interpretations are submitted after the fact. In other words, adisagreement on interpretation of a requirement has occurredbetween the parties involved long after the work or examination(s)has been completed. Obviously, the SCV reply is not going tofavor one of the parties. It is therefore of utmost importance toresolve, if at all possible, any differences before work progressesbeyond the point of no return. For example, the radiographictechnique and completed radiographs should be reviewed by allparties involved as soon as possible upon the completion ofsuch work. It is too late to submit a request for a CodeInterpretation after the component or vessel has been completedand is sitting, waiting to be Code-stamped and accepted by allparties involved.

20.2.1 Essential and Nonessential Variables Resulting from a request by the ASME Post Construction Code

Standards Committee, Subcommittee V established essential vari-ables for demonstrating performance capabilities to qualify proce-dures. While the request was specific to the ultrasonic examina-tion method, the Subcommittee decided to proactively defineessential variables for all NDE methods in Section V. The formatultimately selected was based on the essential/nonessential vari-able format used by Section IX. Please note: Essential variable vs.

NONDESTRUCTIVEEXAMINATION (NDE)

Jon E. Batey1

1Harold C. Graber was the author for the first edition of this chaptereditor

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nonessential variable is only important when procedure qualifica-tion is required by a referencing code. Otherwise, the combinedlists of essential and nonessential variables simply represent itemsrequired to be described in a written procedure.

20.3 RELATION TO OTHER ASMECODE BOOK SECTIONS

As previously mentioned, Section V primarily addresses thetest methods and methodology for NDE. Other ASME Code sec-tions, such as I, III, VIII, and XI [4][7], include specific method-ology requirements and provide acceptance criteria for the testmethods referenced. To ensure that all contract requirements aresatisfied, users must understand the relationship of Section V tothe Codes other sections. As an example, let us step through therequirements that must be satisfied when the contract specifies forthe component or vessel to be built in accordance with ASMECode Section I, 2007 edition with 2007 addenda [4].

First, we must look in Section I and determine the requirementsfor NDE. In Section I, we find paragraph PW-11 to be pertinent,as it is called Radiographic and Ultrasonic Examination ofWelded Butt Joints. Selecting the radiographic requirement, wefind that Table PW-11 requires all longitudinal and circumferen-tial butt-welded joints to be radiographically examined through-out their entire length in accordance with Section V Article 2 andalso meet the requirements of paragraph PW-51, with someexceptions. Assuming now that radiography for a butt-weldedjoint is required, we must look at the requirements of paragraphPW-51, which is titled Acceptance Standards for Radiography.The text of subparagraph PW-51.1 states that welds shall beexamined throughout their entire length by the x-ray or gamma-ray method in accordance with Section VArticle 2, except thatthe requirements in Article 2, paragraph T-274 (GeometricUnsharpness) are to be used as a guide rather than for the rejec-tion of radiographs unless the geometrical unsharpness exceeds0.07 inch. Subparagraph PW-51.2 states that a single-welded cir-cumferential butt joint with a backing strip may be radiographedwith the backing strip intact, provided the backing strip is not tobe subsequently removed and its image does not interfere with theinterpretation of the radiographs. This is an example of where aCode section provides technical requirements that differ from therequirements of Section V.

Next, let us look at the requirements for personnel qualification(PQ). Again, Section I, paragraph PW-50.1 provides requirementsfor PQ that states the manufacturer shall certify that personnelperforming and evaluating radio-graphic examinations requiredby Section I have been qualified and certified in accordance withtheir employers written practice. The American Society forNondestructive Testing (ASNT) [8] documents SNT-TC-1A [9] orCP-189 [10] shall be used as a guideline for employers to estab-lish their written practice. Provisions for training, experience,qualification, and certification shall be provided and described inthe manufacturers quality control system. PW-50.2 requires PQby examination, including the certification of NDE Level III per-sonnel beginning with the 2004 Edition of Section I with 2004Addenda. Paragraph PW-50.3 addresses how personnel recertifi-cation is handled. This is important information to users, for theapplicable edition of the ASNT document depends on the specificedition of the Code and is provided in Section I, Table A-360. Forexample, Table A-360 of the 2007 edition of Section I with 2007addenda specifies SNT-TC-1A (2001) as the applicable edition.

Another significant requirement of Section I is acceptance cri-teria. Paragraphs PW-51.3, PW-51.3.1, PW-51.3.2, PW-51.3.3,and PW-51.3.4 provide the acceptance criteria for imperfections(a term defined in Section V, Article 1, Mandatory Appendix I,Glossary of Terms, paragraph I-130). Paragraph PW-51.3.4addresses rounded indications, and the size, frequency, and dis-tribution are provided in detailed charts located in Appendix A-250. A typical example is as shown in Fig. 20.1. The chartsprovide graphic illustrations of random, isolated, and cluster dis-tributions, as well as aligned indications. Charts are provided forweld thicknesses of in., inclusive; over in., inclusive;over in., inclusive; over in., inclusive; over 24 in.,inclusive; and over 4 in.

Section I, paragraph PW-51.4 provides requirements for reten-tion of completed radiographs. The current requirement (i.e., the2007 edition with 2007 addenda) is that a complete set of radi-ographs for each job shall be retained by the manufacturer andkept on file for a period of 5 yr.

This overview provides an insight into the interrelationships ofthe Code sections. Section I was selected as an example for sim-plicity; however, users should be cautioned that other Code sec-tions for example, Section III [5] or Section XI [7]provide manymore complex requirements and significant changes to therequirements of Section V.

It is important to remember that contract requirements shouldbe reviewed and the applicable edition of the Code determinedbefore production is started. This information should then be pro-vided to all personnel involved to ensure that manufacturingplans, tests, and nondestructive examinations are performed inaccordance with the correct requirements of the applicable Codeedition. Making certain that the correct information is available atthe start will prevent subsequent delays caused by the discoveryof a noncompliance for work performed to the wrong Code edi-tion or wrong addenda. Any noncompliance could very well resultin an inquiry to the Code Committee, who cannot always resolvethe inquiries in a timely fashion.

20.4 ARTICLE 1: GENERALREQUIREMENTS

Section V, Article 1 addresses general requirements that areunique and applicable in most cases to the other articles. Thescope of this article provides important information about theinterface of Section V with other Code sections or documents. Ofsignificance is the statement: This section of the Code containsrequirements and methods for nondestructive examination (NDE),which are Code requirements to the extent they are specificallyreferenced and required by other Code sections or referencingdocument. The text also states that the test methods are intendedto detect surface and internal discontinuities in materials, welds,and fabricated parts and components.

The paragraph titled General provides an explanation ofSubsections A and B. Subsection A describes the test methods tobe used. When reference is made to a paragraph belonging to anarticle in Subsection A or to some other Code section, all of thatparagraphs rules are applicable. For example, reference to para-graph T-270 (Examination) includes all the rules in subparagraphsT-271 through T-277.3. Subsection B lists documents and stan-dards adopted by Section V, which are intended to be used forinformation purposes and are nonmandatory unless specificallyreferenced in whole or part by the articles under Subsection A or

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COMPANION GUIDE TO THE ASME BOILER & PRESSURE VESSEL CODE 3

other Code sections. It is important to note that a reference madeto a standard is only mandatory to the extent specified in the arti-cle or other Code section. In essence, this means that an articlemay only reference a specific paragraph in an ASTM Standard[2]; therefore, only the referenced paragraph becomes a Coderequirement, and the remainder of the standards requirements donot apply.

The paragraph titled General also addresses personnel quali-fication and certification (PQ). This paragraph is probably one ofthe most significant in Subsection A because of the various alter-natives for meeting PQ requirements. For instance, let us take alook at the current requirements in Article 1. The first documentreferenced is the 2001 edition of SNT-TC-1A, PersonnelQualification and Certification in Non-destructive Testing [9],published by the ASNT. A second document referenced is the2001 edition of ANSI/ASNT CP-189 [10], also published by theASNT. Either one of these documents may be used for PQ, unlessrequirements to the contrary are provided by other applicableCode sections. To further emphasize the importance of working tothe control requirements, note that in the 1995 edition of SectionV, Article 1, paragraph T-140, the pertinent reference is to the1992 edition of SNT-TC-1A, while in the 1989 edition, paragraphT-140 specifies the use of the 1984 edition of SNT-TC-1A. Thisexample illustrates how requirements change when later versionsof documents are adopted. Again, users should be cautioned thatthe PQ version and edition listed in Section V, Article 1 may notbe the same as the version and edition listed in a previous editionof Section V or in another Code section.

Paragraph T-120 provides additional clarifications for PQ andshould be reviewed to ensure compliance. One last item of signifi-cance in paragraph T-120 is that it addresses limited certification.

T-120(i) allows an exception to the requirements of SNT-TC-1 Aor CP-189 regarding training and experience of personnel who donot perform all of the operations of a NDE method or whoperforms examinations of limited scope. However, if this limitedcertification is used, the limitations must be described in themanufacturers written practice and listed on the individualscertification records.

20.4.1 Paragraph T-150, Procedure This paragraph provides the requirements for NDE technical

procedures used for the test methods in Subsection A. It addressessituations where special configurations and materials may requiremodified methods and techniques, in which case the manufacturermust develop special procedures that are equivalent or superior tothe test methods and techniques described in the applicable arti-cle. The special procedure or technique must be capable of pro-ducing interpretable results when one is performing the test underthe special conditions. The procedure or technique may be a mod-ification or combination of methods described in the article.Depending on the quality system used and as required by the ref-erencing Code section, the special procedure shall be submitted tothe Authorized Inspector (AI) for acceptance and then adopted aspart of the manufacturers quaity control program.

Paragraph T-150(c) specifically states when required by a ref-erencing Code section, all nondestructive examinations performedunder this Code section shall be done to a written procedure. Italso requires the procedure to be demonstrated to the satisfactionof the AI. When required, written procedures must be made avail-able to the Inspector on request. At least one copy of the writtenprocedure shall be readily available to the manufacturers nonde-structive examination personnel for their reference and use.

FIG. 20.1 CHARTS FOR T 1-1 IN., INCLUSIVE (Source: Fig. 3.1, Section I of the ASME B&PV Code)


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20.4.2 Paragraph T-160, Calibration This paragraph is important in that it requires the manufacturer,

fabricator, or installer to ensure that all calibrations of equipmentare performed in accordance with the applicable articles inSubsections A or B. It also provides requirements addressing theuse of special procedures and stipulates that the manufacturer,fabricator, or installer is responsible for specifying what calibra-tions are necessary and the calibration frequency.

20.4.3 Paragraph T-170, Examinationsand Inspections

This paragraph defines the term Inspector and the Inspectorsduties and authority. Furthermore, it establishes the distinctionbetween the terms inspection and examination. The user isadvised to read this paragraph in its entirety to understand the dis-tinctions of the variety of terms used.

20.4.4 Paragraph T-180, Evaluation This paragraph simply informs the user of the fact that Section

V does not provide acceptance criteria for the test methods listedin the articles and that one must refer to the referencing Code sec-tion for this information.

20.4.5 Paragraph T-190, Records Records and documentation must be maintained by the manu-

facturer, fabricator, or installer in accordance with the applicablerequirements of Subsections A or B and the referencing Codesection.

20.4.6 Mandatory Appendix I, Glossary of Terms This important appendix provides the standard terminology for

NDE. The ASTM Standard E-1316, Standard Terminology forNondestructive Examination, has been adopted as SE-1316 and islocated in Article 30. This standard provides terminology for allNDE methods. However, Mandatory Appendix I in addition pro-vides specific Code terms that either do not appear in E-1316 orare terms whose definitions have been changed to satisfy theCode. Users of Section V should be familiar with the terms inMandatory Appendix I and, in particular, with the definitions fordefect, discontinuity, evaluation, false indication, flaw, flaw char-acterization, imperfection, interpretation, nonrelevant indication,and relevant indication. All of these terms are used by the variousCode sections and in their acceptance criteria. It is very importantto understand the terms and their associated definitions whenmaking acceptance-rejection decisions.

20.4.7 Article 1, Nonmandatory Appendix A Article 1, Nonmandatory Appendix A adds Table A-110, provided

here as Table 20.1, listing common imperfections vs. the type ofNDE methods that are generally capable of finding them.Nonmandatory Appendix A was developed for people with a limitedbackground in NDE, not for experienced NDE personnel. Users areencouraged to read the cautionary statement in A-110 plus the notesto Table A-110. Specifically, Table A-110 must not be used as a basisfor requiring nor for prohibiting a particular type of NDE method.

20.5 ARTICLE 2: RADIOGRAPHICEXAMINATION

Article 2 covers the radiographic test method used for theexamination of materials, including castings and welds. Included

in the article are eight Mandatory Appendices (I-VII) and threeNonmandatory Appendices (A, C, and D). The MandatoryAppendices are the following:

Appendix I, In-Motion Radiography. Appendix II, Real Time Radioscopic Examination. Appendix III, Digital Image Acquisition, Display, and

Storage for Radiography and Radioscopy. Appendix IV, Interpretation, Evaluation, and Disposition of

Radiographic and Radioscopic Examination Test ResultsProduced by the Digital Image Acquisition and DisplayProcess.

Appendix V, Glossary of Terms for Radiographic Examination. Appendix VI, Digital Image Acquisition, Display,

Interpretation, and Storage of Radiographs for NuclearApplications.

Appendix VII, Radiographic Examination of Metallic Castings. Appendix VIII, Radiography Using phosphor Imaging Plate.

Users should be aware that before the 1998 edition of SectionV, Radiographic Examination of Castings was covered in Article3. The 1998 edition of Section V now covers RadiographicExamination of Metallic Castings in Mandatory Appendix VII.When using an appendix, the requirements as stated in the appen-dix apply as well as the requirements of the article; therefore,users should be cautioned to consider this when using a specialtest technique in the applicable appendix.

The Nonmandatory Appendices (A, C, and D) are as follows: (A) Recommended Radiographic Technique Sketches for Pipe

or Tube Welds. Techniques used for examination of pipeand welds are illustrated, providing guidance for varioustypical technique setups.

(C) Hole-Type IQI Placement Sketches for Welds. Figures thatillustrate typical hole-type IQI placement for welds areprovided. Not being all-inclusive, they do not cover allapplications of production radiography; however, they doprovide a wide range of technique applications and serveas a tutorial.

(D) Number of IQIs (Special Cases). Figures that illustrateexamples of the required number and placement of IQIsused for special cases are provided. Paragraph T-277.2describes the requirements for special cases, and the figuresprovide pictorial illustrations of IQI placements for typicalconfigurations.

Not all paragraphs in Article 2 will be addressed here, but onlythose of special significance.

20.5.1 Paragraph 210 Scope This paragraph covers the scope of the article. Note the require-

ment that this article shall be used together with Article 1. Thissimply means that the general requirements provided in Article 1also apply unless stated otherwise or are modified by other Codesections or reference documents. The scope also specifies that theapplicable definitions for terms used in the article are those pro-vided in Mandatory Appendix V.

20.5.2 Paragraph T-220 General Requirements Paragraph T-220 covers the general requirements of the article,

including some very significant requirements that must be careful-ly addressed by users. The first item concerns procedure and is


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therefore of great importance. In fact, for good practice regardless ofwhether a Code section requires a procedure, it is always advisableto prepare a written procedure covering all of the items listed in theparagraph. The procedure serves several purposes. Foremost, it pro-vides the necessary guidance for the radiographer to properly per-form radiography or radioscopy during production and later helpsthe radiographic interpreter prepare the required documentation.Whether a procedure is obligatory depends on the requirements stat-ed in the pertinent Code sections. As an example of where a writtenprocedure is required, Section III, Division 1, Subsection NB,Article NB-5000, paragraph NB-5112 states the following: Allnondestructive examinations required by this Article shall be per-formed in accordance with detailed written procedures which havebeen proven by actual demonstration to the satisfaction of theInspector [5]. Procedure demonstration and compliance to the writ-ten procedure is satisfied by assuring the required density and properimages appear on the production or technique radiographs.

20.5.3 Paragraph T-222, Surface Preparation Surface preparation is probably one of the most subjective and

difficult requirements to deal with satisfactorily for all partiesinvolved. The requirement addresses both materials (includingcastings) and welds. The basic requirement for materials is thatthe surface being examined must satisfy the applicable MaterialSpecification or referencing Code section. Additional surface con-ditioning by manual or mechanical processing may be required toassure that surface irregularities are removed to the extent theycannot mask or be confused with any discontinuity image on theradiograph. For welds, the requirement is the same, but with theadditional requirements that weld ripples or weld surface irregu-larities on both sides of the weld (where accessible) shall be pre-pared. This is where the subjectivity comes in. To what extentmust the surface be prepared to ensure that any remaining surfaceirregularity images cannot mask or be confused with images of adiscontinuity? For example, in most cases as-welded surfaceswhere the weld ripples or valleys between beads are slight andessentially smooth, these irregularities will not appear as imageson the radiograph because of their subtlety. However, if the weldripples or valleys between beads are extreme, they will appear assignificant light/dark images on the radiograph. Depending on theheight of the ripples and the depth of the valley between beads,the density of the images of these irregularities will be pro-nounced on the radiograph. If disagreements between partiesoccur regarding whether the surface irregularities can mask a dis-continuity, one common way to resolve the impasse is to preparethe surface of a worst-case condition until the irregularities areremoved entirely. If images appear upon reradiography of theselected area, then obviously a subsurface discontinuity is presentand requires disposition. Remember the time to resolve any dif-ferences is as soon as possible after completing the radiography.This promptness serves two purposes: (1) it provides the inter-preters with an opportunity to visually observe the questionablearea(s), and (2) it allows for any additional surface conditioning tobe preformed to confirm the presence of unacceptable discontinu-ities and in some cases before the area becomes inaccessible.

20.5.4 Paragraph T-226, Extent of Examination The requirement is that the extent of examination shall be as

specified by the referencing Code section. Again, it is importantto be familiar with Code section and contract requirements. Forexample, Section VIII, Division 1, paragraph UW-52 providesrules for spot examination of welded joints [6].

20.5.5 Paragraph T-230, Equipment and Materials Subparagraph T-231.2 addresses film processing and references

two ASTM Standards [2] adopted by the Code: SE-999 and SE-94, both of which are located in Article 22. It is important to note,however, that these two standards are to be used as guides and, assuch, are not mandatory.

Subparagraph T-233 covers IQI Design. The ASTM StandardsE-1025 and E-747 provide IQI design requirements that havebeen adopted by the Code as SE-1025 and SE-747 and shall befollowed in their entirety except that the largest wire number orthe wire identity number may be omitted. (SE-1025 and SE-747standards are also found in Article 22.) An example of the hole-type IQI Design is shown in Fig. 20.2. Tables T-233.1 (given hereas Table 20.2) and T-233.2 (given here as Table 20.3) provide alisting of ASME Standard IQIs for hole and wire-type IQIs. Table20.2 provides the hole-type IQI designation, thickness, and 1T,2T, and 4T hole diameters. It should be noted that this table is forstandard IQIs, but if the situation warrants, nonstandard IQIs maybe used. Table 20.3 provides the four sets of wire IQIs and theassociated wire sizes in each set.

20.5.6 Paragraph T-260, Calibration This paragraph is important because users are required to provide

documented evidence of the physical size of x-ray and gamma-raysources. This is another requirement that is vulnerable to audit.

T-262 (Step Wedge Film and Densitometer) covers calibration ofthe densitometer. A calibrated step wedge film traceable to a nation-al standard is also required. Documentation of the authenticity of thecalibrated step wedge film should be maintained and kept on file.

20.5.7 Paragraph T-270, Examination Paragraph T-271 covers the requirements for single-wall and

double-wall radiographic techniques. It should be noted that thedouble-wall radiographic technique where the radiation passesthrough two walls and the material or weld in both walls is viewedfor acceptance is limited to materials and welds 3 in. (89 mm) orless in nominal outside diameter. Other restrictions for number ofexposures and radiation beam offset are also included.

Nonmandatory Appendix A provides illustrations of techniquesused for the examination of pipe and tube welds. Again, theseillustrations are not mandatory, but provide excellent detailedinformation for establishing the proper technique. Paragraph T-272 covers radiation energy.

Paragraph T-274 covers geometric unsharpness limitations.Geometric unsharpness is directly related to the physical size of agamma-ray source or the focal spot of an x-ray machine. Thesmaller, the better and the closer the radiation source can be inrelation to the film. This paragraph provides the maximum geo-metric unsharpness permitted for various material thicknesses. Itshould be noted that the referencing Code section, excludes ormodifies this requirement in some cases. Geometric unsharpness(Ug) values can be calculated in accordance with the formula Ug= Fd/D, provided in this paragraph.

Paragraph T-275 covers location marker requirements both forsingle-wall and double-wall viewing and for using a map wheninaccessibility or other limitations prevent placement of markersas required. Figure T-275 provides location marker sketches forvarious typical configurations and radiation source locations.

Paragraph T-276, on IQI selection, is important and must becarefully addressed. One must ensure that the IQI selected is forthe nominal single-wall thickness of the object, part, or compo-nents being radiographed. Table T-276 (given here as Table 20.4)

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FIG. 20.2 IQI DESIGN (Source: Fig.1, Article 22, Section V of the ASME B&PV Code)

provides the IQI required for single-wall material with thicknessesup to 20 in. The table also provides the hole-type IQI designation,and if a wire IQI is used, the required wire to be imaged. TheseIQI requirements are provided for both source-side and film-sideIQI placement.

Paragraph T-276 also provides requirements for IQI selection forwelds with reinforcements and without reinforcements. For weldswith reinforcements, it is important to note that IQI selection isbased on the nominal single-wall thickness plus the estimated weld

reinforcement, not to exceed the maximum permitted by the refer-encing Code section. For welds without reinforcement, the IQI isbased on the nominal single-wall thickness, and backing rings orstraps are not considered part of the weld thickness. Radiographicpersonnel should be very familiar with these requirements; notethat for welds with reinforcement, the estimated reinforcement (i.e.,it does not have to be physically measured) is considered whendetermining the total thickness upon which the IQI is based. One isreminded that the maximum reinforcement allowed cannot be


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exceeded. If the reinforcement is close to the maximum, then obvi-ously one must physically measure it to ensure that the maximum isnot being violated. Paragraph T-276 also covers IQI requirementsfor dissimilar metal welds joining dissimilar base materials.

Paragraph T-277 covers the use of IQIs and the specific place-ment and number of IQIs. Film-side IQIs are permitted for those

cases where inaccessiblity prevents hand-placing the IQI on thesource side. For example, a pipe weld is radiographed using anisotope placed on the I.D. of the pipe, and because the weld areacannot be reached physically by hand, it is permissible to use afilm-side IQI in this case. Paragraph T-277.2 provides require-ments and Nonmandatory Appendix D provides guidance anddirection for placement of IQIs for special applications.

20.5.8 Paragraph T-280, Evaluation This paragraph covers several important requirements.

Paragraph T-281, Quality of Radiographs, addresses requirementsfor the quality of the completed radiographic film. If proper careand controls are not used in film handling and processing, filmartifacts will occur and, if severe, can mask or be confused withthe image of a discontinuity.

Paragraph T-282, Radiographic Density, is important and mustbe carefully followed because it provides the required values forfilm density. Users should remember that a densitometer is usedto measure film density and density strips or step wedge compar-ison film are used to estimate or judge film density. In caseswhere an absolute value must be determined, the only way tomake the measurement is by using a densitometer.

Paragraph T-285 covers evaluation. After the radiograph(s) havebeen completed, it is the manufacturers responsibility to ensurethat the radiographs have been reviewed, interpreted, properly eval-uated, and accepted in accordance with the requirements of Article2 and, when applicable, the referencing Code section. A copy of thedetails of the radiographic technique and the radiographic reviewform documentation that shall accompany the radiographs.

20.5.9 Paragraph T-290, Documentation An old cliche is that the work is not done until the paperwork

is completed. Paragraph T-291 requires the manufacturer to



prepare and document the details of the radiographic technique,including some specifically required information. The detailslisted are minimums, and it is good practice to include otherspecifics, such as IQI designation and IQI material, shims andshim thickness, and so forth. It is also important to note thatacceptance of the radiographs by the manufacturer or the manu-facturers authorized representative must be completed beforepresenting the radiographs and documentation to the Inspector.Paragraph T-292, Radiographic Review Form, states that themanufacturer is required to prepare a radiographic reivew form;this document provides details of the evaluation of the complet-ed radiograph(s).

20.6 ARTICLE 4: ULTRASONICEXAMINATION METHODS FOR WELDS

Article 4 describes and references requirements for ultrasonicexamination of welds. When performing an examination in accor-dance with any part of the article that is a requirement of a refer-encing Code section, that referencing Code section shall beaddressed for specific requirements for the following: PersonnelQualification/Certification, Procedure and/or Technique require-ments, Examination System Characteristics, Retention andControl of Calibration Blocks, Acceptance Standards, Reportsand Records Retention requirements, Extent of Examinationand/or volume to be scanned. Users of the article should carefullyreview the requirements to ensure that all are satisfied. Therequirements are established for the detection of reflectors in theweld, heat-affected zone, and adjacent base material. Two generalexamination classifications have been established: welds in ferrit-ic product forms other than pipe, and ferritic welds in ferriticpipe. For austentic and high-nickel alloy welds, examination isusually more difficult because of wide variations in the materialproperties even in alloys of the same composition, product form,and heat treatment. Therefore, because of these difficulties, it maybe necessary to modify and/or supplement the provisions of

Article 4 and establish special technique(s), as permitted inArticle 1 paragraph T-150(a).

20.6.1 General Requirements Consistent with the other articles in SCV, Article 4 also activates

Article 1 by stating that when Article 4 is specified by a referencingCode section, the ultrasonic method described in Article 4 shall beused together with Article 1 (General Requirements). Definitions ofterms are provided in Mandatory Appendix III of Article 5.

20.6.2 Written Procedure Requirements The examination shall be performed in accordance with a writ-

ten procedure, and the procedure shall include the following listof information, as applicable:

Weld configurations to be examined, including thicknessdimensions, and base material product form (casting, plate,bar, tube, forging, and so forth).

The surface(s) from which the examination will be performed. Surface condition (examination surface, calibration block). Couplant brand and type. Technique (straight beam, angle beam, contact, or immersion). Angles and mode(s) of wave propagation. Search unit type, size, and frequency. Special search unit wedges, shoes, or saddles. Instrument type. Description of calibration block. Directions and extent of scanning. Records and calibration data to be recorded, and the method

of recording (manual or computer enhanced). Description of automatic alarm and recording equipment (if

used). Scanning (manual vs. automatic). Scan overlap. Computer enhanced data acquisition (when used). Method for discriminating geometric vs. flaw indications. Method for sizing indications. Personnel qualification requirements.


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FIG. 20.3 NON-PIPING CALIBRATION BLOCKS (Source: Fig.T-434.2.1, Section V of the ASME B&PV Code)

20.6.3 Equipment and Supplies

20.6.3.1 Instrument The examination shall be performed witha pulse-echo instrument capable of generating frequencies over therange of 15 MHz. An instrument may be operated at a differentfrequency, provided equal or better sensitivity is demonstrated anddocumented.

20.6.3.2 Search Units and Contact Wedges Search units usedto perform the examination shall meet the following criteria:

Search units may have either single or dual transducer elements.

Contoured contact wedges connected to the search unit maybe used to aid in coupling to the part contour or for soundtransmission (e.g., angle beam mode or transmit receiveapplications). If contact wedges are used, they shall be inplace when performing calibration.

20.6.3.3 Basic Calibration Block Requirements The basic cali-bration block configuration and calibration hole locations shall be asshown in Fig. T-434.2.1 (given here as Fig. 20.3). The material fromwhich the block is fabricated shall be of the same product form andhaving the same Material Specification or equivalent P-number



grouping as one of the materials being examined. P-numbers 1, 3, 4,and 5 are considered equivalent. Calibration block material for dis-similar metal welds shall be based on the material on the side of theweld where the examination is performed. If the examination is per-formed from both sides of the weld, two calibration blocks arerequired, and the calibration block thickness shall be based on theaverage thickness of the weld. When the component material is cov-ered with overlay cladding, the calibration block shall also be cladas well by using the same welding procedure that was used on theproduction part. If the production clad was performed by an auto-matic welding process, and it is impractical to perform automaticwelding on the calibration block, the block may be clad by using amanual process. It is recommended that consideration be given tousing dropouts or prolongations for the calibration blocks that havebeen welded by the production process before their removal fromthe production part. The calibration block shall receive at least theminimum tempering treatment required by the MaterialSpecification for the type and grade, and also a postweld heat treat-ment if the block contains weld(s) other than cladding. The surfacefinish of the calibration block shall be representative of the surfacefinish on the production component(s). The calibration block mate-rial shall be examined 100% using straight beam. Areas of the blockthat contain reflectors providing an indication exceeding the backreflection shall be excluded from the sound path required to obtain asignal from the various calibration reflector(s).

20.6.3.4 Piping Calibration Block Requirements The basiccalibration block as shown in Fig. 20.4 (Fig. 434.3) shall be used.

20.6.3.4.1 Examination of Welds in Materials withDiameters Greater than 20 In. (508 mm) If the examinationmaterial surface is greater than 20 in. in diameter, a calibration blockof essentially the same curvature is desired or, alternatively, a flatcalibration block may be used. As an alternative, when performing

the examination from a convex surface using the straight beamtechnique, Appendix G may be used.

20.6.3.4.2 Examination of Welds in Materials withDiameters Less than 20 In. (508 mm) If the examination mater-ial surface is less than 20 in. in diameter, a curved calibration blockis required. A single curved block may be used to examine sur-faces in the range of curvature 0.91.5 times the basic calibrationblock diameter.

20.6.4 Calibration

20.6.4.1 Screen Height Linearity The instrument shall providea linear vertical presentation within 5% of the full screen heightfor 20100% of the calibrated screen height (baseline to maximumcalibrated screen point or points). A procedure for determining andevaluating screen height linearity is provided in MandatoryAppendix I. The screen height linearity shall be performed at thebeginning of each period of extended use (or every 3 mo. for ana-log instruments and 1yr for digital instruments, whichever is less).Users should pay close attention to maintaining the instrumentscreen height linearity within the limits to ensure accurate flawdetection and sizing.

20.6.4.2 Amplitude Control Linearity The instrument shalluse an amplitude control that is accurate over its useful range to20% of the nominal amplitude ratio. The amplitude controlaccuracy is important for measuring indications beyond the linearrange of the vertical display on the CRT screen. A procedure fordetermining and evaluating amplitude control linearity is providedin Mandatory Appendix II. Determination of amplitude controllinearity shall be performed at the beginning of each period ofextended use (or every 3 mo. for analog instruments and 1yr fordigital instruments, whichever is less). Again, users should pay

;

FIG. 20.4 CALIBRATION BLOCK FOR PIPE (Source: Fig.T-434-3, Section V of the ASME B&PV Code)


12 Chapter 20

close attention to maintaining the amplitude control linearity with-in the limits to ensure proper measurement of indications beyondthe linear range of the vertical display on the CRT screen.

20.6.4.3 Checking and Calibration of Equipment Proper func-tioning of the examination equipment shall be checked and theequipment calibrated by using the required calibration standard(s)at the beginning and end of each examination (when personnel arechanged) and anytime a malfunction is suspected. These requisitesare established as minimums, so users are reminded to pay closeattention to ensuring that examination equipment is functioningproperly at all times. For this reason, periodic calibration verifica-tions over the course of the work shift are strongly recommended,particularly when the examination extends over long time periodssuch as several days or longer. If during any of the checks theequipment is discovered to be functioning improperly, all of thework performed since the last acceptable verification checkrequires reexamination. Again, the importance of verifying calibra-tion cannot be overemphasized, for such verification can save timeby preventing the need for performing a reexamination.

20.6.4.4 System Calibration Calibration shall include the com-plete system used to perform the production examination. Eachcalibration shall be performed from the surface (clad or unclad) ofthe calibration block corresponding to the surface of the compo-nent being examined. Appendices B and C of Article 4 providegeneral techniques for both angle beam and straight beam calibra-tion. Other techniques may be used.

20.6.4.5 Angle Beam Calibration As applicable, the calibra-tion shall include the following requirements in addition to thegeneral requirements specified in Article 4, Appendix B:

(1) distance-range calibration; (2) distance-amplitude correction; (3) echo amplitude measurement from the surface notch in the

basic calibration block.

When an electronic distance-amplitude correction device isused, the primary reference responses from the basic calibrationblock shall be equalized over the distance range to be used for theproduction examination. The response equalization line shall be at4080% of full screen height.

20.6.4.6 Straight Beam Calibration The straight beam calibra-tion requirements are the same as those described for angle beamcalibration, except that echo amplitude measurement is notapplicable.

20.6.4.7 Calibration Check Using the Basic Calibration Blockor Simulator If any part of the examination system is changed, acalibration verification check shall be performed by using the basiccalibration block to verify that /T, /2T, and /T points on the sweepand distance amplitude correction values previously recorded sat-isfy the initial calibration data. At the completion of each exami-nation or series of examinations (when personnel are changed) andevery 4 hr. during the examination, a calibration check using atleast one of the calibration reflectors in the basic calibration blockor simulator shall be performed. The sweep and distance ampli-tude correction values recorded shall satisfy the straight beam cal-ibration verification. When a simulator is used, the checks shall becorrelated with the data obtained during original calibration on thebasic calibration block. A simulator may be, for example, an IIW

34

12

14

block or electronic simulation. The simulation used shall be com-pletely identifiable on the calibration sheet(s). The accuracy of thesimulator checks shall be confirmed by using the basic calibrationblock at the conclusion of each period of extended use or every 3 mo., whichever is less. The requirements for calibration confir-mation shall be met.

Calibration confirmation is not satisfied for sweep-range cor-rection if a point on the DAC has moved on the sweep line bymore than 10% of the sweep reading or 5% of the full sweep,whichever is greater. One must then correct the sweep-range cali-bration and note the correction on the examination records. Ifreflectors are recorded on the data sheets, those data sheets shallbe voided and the new calibration recorded. All recorded indica-tions since the last valid calibration or calibration check shall bereexamined with the corrected calibration and their values record-ed on the data sheets. Calibration confirmation is not satisfied forDAC correction if a point on the DAC curve has decreased 20%or 2 db. In such a case, all data sheets since the last valid calibra-tion or calibration check shall be marked void. A new calibrationshall be performed and recorded, the area covered by the voideddata shall be reexamined, and previously recorded indications val-ues shall be changed and recorded on the data sheets.

20.6.5 Examination

20.6.5.1 Examination Coverage The volume shall be examinedby moving the search unit over the examination surface to scan theentire volume. To ensure complete coverage, each pass of thesearch unit shall be overlapped a minimum of 10% of the transduc-er element dimension perpendicular to the direction of the scan.

20.6.5.2 Rate of Search Unit Movement The rate of the searchunit movement shall not exceed 6 in./sec. unless calibration is ver-ified or confirmed at the scanning speed used.

20.6.5.3 Surface Preparation The base metal on the side(s) ofthe weld from which the examination will be performed shall befree from weld spatter and foreign matter, and surface irregulari-ties shall be removed by mechanical means to the extent that suchremoval does not interfere with the examination. The weld surfaceshall also be free from weld spatter and foreign matter, and wheresurface irregularities interfere with the examination, the surfaceshall be prepared to the extent necessary for the irregularities notto interfere.

20.6.5.4 Scanning Requirements The base material adjacent tothe weld that will be involved in the examination shall be scannedusing the straight beam technique to detect any base metal reflec-tors that may interfere with the angle beam test results. The loca-tions of the reflectors shall be recorded for reference purposes onlyand shall not be evaluated in accordance with the acceptance crite-ria for the weld.

Angle beam scanning for reflectors oriented parallel to theweld shall be performed with the angle beam directed approxi-mately at right angles to the weld axis from two directions (wherepossible). The search unit shall be manipulated so that the soundbeam passes through the required volume of weld to be examined.Scanning shall also be performed at a gain setting of at least twotimes the primary reference level; however, evaluation of reflec-tors shall be performed at the primary reference level.

Angle beam scanning for reflectors oriented transverse to theweld shall be performed with the angle beam directed essentially



parallel with the weld. The search unit shall be manipulated sothat the sound beam passes through the required volume of weldto be examined. Scanning shall be performed at a gain setting ofat least two times the primary reference level; however, evaluationof reflectors shall be performed at the primary reference level.The search unit shall be rotated 180 deg. and the examinationrepeated.

20.6.5.5 Cladding The following requirements apply only toweld-metal-overlay cladding and when examination is required bythe referencing Code section. Test requirements for roll bond orexplosive clad plate shall be performed in accordance withSA-578, located in Article 23. Two examination techniques areprovided for weld-metal-overlay cladding: the first is for lack ofbond and clad defects, the second for lack of bond only.

20.6.5.5.1 Equipment, Calibration Block, Calibration, andExamination Requirements for Technique 1 Dual search unitsset up for pitch catch shall be used. The included angle betweenthe two beam paths shall be such that maximum sensitivity of thesearch unit is in the area of interest. The calibration block shownin Fig. T-434.4.1 (given here as Fig. 20.5) shall be used. The blockshall be clad using the same weld process as was used for theproduction part. The surface condition shall be equivalent to theproduction part. Either a in. (1.6 mm) diameter in. longside-drilled hole located at the clad interface or a in. (3.2 mm)flat-bottom hole drilled through the base material and terminatingat the clad interface may be used. The thickness of the blocks base

18

* 112116

material shall be at least two times the thickness of the cladding.The examination shall be performed from the clad surface, and theentire clad surface shall be examined where practical. The exami-nation shall be performed with the plane separating the elementsof the two search units placed parallel to the axis of the weldbead(s). Scanning shall be performed at two times the primary ref-erence level and by moving the search unit perpendicular to theweld direction. All indications shall be evaluated at the primaryreference level.

20.6.5.5.2 Equipment Calibration Block, Calibration, andExamination Requirements for Technique 2 Straight beamsearch units shall be used. A cladded calibration block is requiredusing the same welding process as used in production, with thesurface condition representative of the production part is used. A in. (10 mm) flat-bottom hole is drilled through the base material,terminating at the claddingweld-metal interface. The thickness ofthe base material shall be at least twice the thickness of the weld-overlay cladding. Calibration shall be performed by placing thesearch unit on the calibration block opposite from the drilled hole.The search unit shall be manipulated to obtain a maximumresponse from the calibration hole, and the gain shall be set so thatthis response is 80% (5%) of full screen height. This is the pri-mary reference level. Scanning shall be performed at a gain settingat least two times the primary reference level, and scanning shallbe performed on the clad surface if calibration is performed fromthe clad surface. All indications shall be evaluated at the primaryreference level.

38

FIG. 20.5 CALIBRATION BLOCK FOR TECHNIQUE 1 (Source: Fig.T-434.4.1, Article 4, Section V of the ASME B&PV Code)


14 Chapter 20

20.6.6 Evaluation Any imperfection that causes an amplitude response in excess

of 20% DAC (or 40% of the rejectable flaw size for non-distanceamplitude techniques) shall be investigated to the extent that itcan be evaluated in terms of the acceptance criteria required bythe referenced Code section.

20.6.7 Reports and Records A report of the examination is required. The report shall include

a record (which may be a marked-up sketch) indicating the volumeexamined. The report shall also include the location of eachrecorded reflector and identify the operator who performed (partlyor entirely) the examination. Instrument calibrations, system cali-brations, and calibration block identification, as required, shall beincluded in the calibration records. Examination records shouldinclude the following information in addition to any additionaldetailed information specified by the referencing Code section:

(1) procedure identity; (2) examination equipment; (3) personnel identity and qualification level; (4) calibration sheet identity; (5) identification of weld or volume scanned and any inacces-

sible areas; (6) identification of surface(s) used in the examination; (7) a map or record of indications detected or, alternatively,

areas clear of indications; (8) the date(s) and time(s) when the examination was per

formed; (9) type of couplant used;

(10) calibration block identification and calibration data(including simulators, if used);

(11) surface condition; (12) frequencies and angles used; (13) equipment used (search units, cables); and (14) a listing of any special equipment used. Records of any evaluations of indications shall be maintained

and documented as required by the referencing Code section.

20.6.8 Article 4, Nonmandatory Appendix L Article 4, Nonmandatory Appendix L provides methodology

that can be used to demonstrate the ability of an ultrasonic systemto size depth and length of indications using time-of-flight-diffraction (TOFD). Nonmandatory Appendix L specifically per-tains to a dual-probe, computer imaging TOFD technique andincludes a system for classifying imperfections.

20.6.9 Article 4, Nonmandatory Appendix N Article 4, Nonmandatory Appendix N provides useful informa-

tion that can be used as an aid for interpreting TOFD images.

20.7 ULTRASONIC EXAMINATIONMETHODS FOR MATERIALS

Article 5 describes the methodology for ultrasonic examinationof plate, pipe, forgings, castings, and for thickness determina-tions. Definitions of terms used found in Mandatory Appendix IIIof this Article. When SA, SB, and SE documents are referenced,they are located in Article 23.

20.7.1 General Requirements When Article 5 is specified by a referencing Code section, the

General Requirements section of Article 1 applies. Note: Writtenprocedure requirements, equipments requirements, maximumsearch unit movement rate, calibration requirements, evaluationrequirements, and documentation are very similar to thosedescribed for Article 4 in 20.6.

In general, calibration reflectors in calibration blocks aredescribed in referenced SA, SB, and SE documents in Article22. However, there are important exceptions located in T-534.For example, longitudinal notches of 1 in. (25 mm) maximumlength and 1/16 in. (1.6 mm) maximum width are required forpipe examinations. The notch depth cannot exceed 0.004 in.(0.10 mm) or 5% of the nominal wall thickness, whichever isgreater.

20.7.2 Examination Most examination requirements are described in the following

documents located in Article 23:

Plate-SA-435/SA-435M, SA-577/SA-577M, SA-578/SA-578M, or SB-548, as applicable.

Forgings/Bars-SA-388/SA-388M, or SA-745/SA-745M, asapplicable.

Tubular Products (such as Pipe)SE-213 or SE-273, asapplicable.

CastingsSA-609/SA-609M. Bolting MaterialSA-388/SA-388M. Thickness MeasurementSE-797. Inservice Examination of CladdingSA578/SA-578M.

Note: This requirement excludes weld metal overlay; exami-nation requirements for weld metal overlay are described inArticle 4, T-473.

As mentioned previously, Article 5 amends the SA, SB, and SEdocuments for certain requirements. In the case of conflictingrequirements, the amended exceptions in Article 5 take prece-dence over the requirements in the SA, SB, and SE documents.As an example, Article 5 amends the examination requirements ofSA-609/SA-609M for casting by stating in T-571.4(a), Forstraight-beam examinations, the sensitivity compensation in para-graph 8.3 of SA-609/SA-609M shall not be used.

Additional examination requirements are described in theMandatory Appendices to Article 5 as follows:

Pumps and ValvesMandatory Appendix I. Inservice Examination of Nozzle Inner Radius and Inner

Corner RegionMandatory Appendix II. Inservice Examination of BoltingMandatory Appendix IV.

20.8 ARTICLE 6: LIQUID-PENETRANTEXAMINATION

Article 6 describes the methodology and technques used forliquid-penetrant examinationone of the most frequently usedmethods and one that is required and referenced by many of theCode sections. When Article 6 is specified by a referencing Codesection, the General Requirements section of Article 1 is alsoapplicable.



20.8.1 Procedures and Procedure Revision(s) The examination shall be performed in accordance with a writ-

ten test procedure, and the following items should be consideredfor inclusion in the procedure:

(1) Material shapes and sizes, and extent of examination. (2) Type and letter or numerical designation of each penetrant,

penetrant remover, emulsifier, and developer. (3) Details for preexamination cleaning and drying, including

the precleaning material(s) used and the minimum dryingtime.

(4) Details for the application of the penetrant, penetrant dwelltime, and temperature of the penetrant and of the part beingexamined (if the test is performed outside the temperaturerange of 50125F).

(5) Details for removal of excess penetrant and drying of thesurface before application of developer.

(6) Details for applying the developer and the developing dwelltime before interpretation.

(7) Minimum light intensity. (8) Details for postcleaning. (9) Personnel qualification requirements.

20.8.2 Equipment The equipment, consisting of penetrant materials, includes all

materials used for the examination, such as penetrants, cleaners,emulsifiers, solvents, cleaning agents, developers, and so forth.

20.8.3 Control of Contaminants Article 6 Appendix-II provides detailed information and

requirements for the control of contaminants, as well as the certi-fication requirements for penetrant materials (including preclean-ing solvents) that will be used on nickel-base alloys, austeniticstainless steels, and titanium materials. Article 24 contains SDstandards 129, 1552, 516, 808, and SE-165, all of which are usedfor reference for material analysis procedures. Specific analysisrequirements are provided in Article 6 Appendix-II. Users shouldbe aware of the necessity to obtain certifications from the manu-facturers of penetrant materials and also to file the certificationsfor verification during subsequent audits.

20.8.4 Surface Preparation The examination may be performed on the part without any sur-

face conditioning, provided the surface irregularities cannot maskindications of unacceptable discontinuities. Surface preparation bymechanical means may be required. Article 24 contains StandardSE-165, Annex 1, and is a reference procedure for additional infor-mation on general precautions relating to surface conditioning. Thisreference should be reviewed by users for consideration in listingsurface finish requirements in the test procedure. The test surfaceand all adjacent surfaces within 1 in. shall be dry and free of anyextraneous materials (grease, dirt, scale, weld flux, spatter, oil, andso forth). Degreasing or ultrasonic cleaning methods may berequired. After cleaning, the surface(s) shall be dried by normalevaporation or by using forced hot or cold air. The minimum dryingtime shall be established and specified before the penetrant applica-tion to ensure that the cleaning solvent has completely evaporated.

20.8.5 Techniques Either a color-contrast (visible) penetrant or a fluorescent pene-

trant shall be used with one of the following processes:

(1) water washing; (2) postemulsifying; (3) solvent removal. For the standard technique, the temperature of the penetrant and

surface of the part being examined shall be in the range of 40F(5C)125F (52C). When it is not practical to comply with thistemperature range, other temperatures may be used if the procedureis both qualified and in accordance with the technique requirementsfor nonstandard temperatures, as specified in Article 6.

20.8.6 Calibration Both visible and fluorescent light meters shall be calibrated

annually, or whenever the meter has been repaired.

20.8.7 Examination The penetrant may be applied by any suitable means. The pene-

trant dwell time is critical, and the dwell time shall be as specifiedin Table 20.5 (Table T-672) or as qualified by demonstration forspecific applications. The removal of excess penetrant is critical,

TABLE 20.5 MINIMUM DWELL TIMES (source: Table T-672, Section V of the ASME B&PV Code)


16 Chapter 20

and Article 6 provides specific requirements for removal of water-washable, postemulsifying, and solvent-remover penetrants. Dryingof the surface after the penetrant removal can be accomplished byblotting or by using circulating air for water-washable or postemul-sifying penetrants; for solvent removal, drying may be performed bynormal evaporation, blotting, wiping, or the use of forced air.Developer application for wet or dry developers may be performedby any suitable means. The minimum developing time shall be asspecified in Table T-672 (given here as Table 20.5).

20.8.8 Interpretation Final interpretation of the test results shall be made within 1060

min. after the developing dwell-time requirement has been satisfied.Longer periods are permitted if the bleed-out does not alter theresults. When using color-contrast penetrant, the test results shall beviewed under a light intensity of 100 foot-candles (1000 Lx); forfluorescent penetrants, the test results shall be viewed using a blacklight with an intensity of 1000 mW/sq. cm on the surface of thepart. The black light intensity must be checked prior to use andafter completion of examination(s), and it is good practice to docu-ment verification of the check.

20.8.9 Evaluation All indications shall be evaluated in accordance with the accep-

tance standards of the referencing Code section.

20.8.10 Documentation and Records Documentation and records shall be completed in accordance

with the requirements of the referencing Code section.

20.9 ARTICLE 7: MAGNETIC-PARTICLEEXAMINATION

Article 7 describes the requirements and methodology for theperformance of the magnetic-particle examination test method.Magnetic-particle examination is a widely used test method by theCode and is referenced as a requirement in many Code sections.Article 25 contains SE-709, which is a reference standard andshould be consulted by users when establishing their test proce-dures. Also, when Article 7 is specified by a referencing Code sec-tion, the requirements of Article 1 apply. In some cases, the refer-encing Code section alters the Article 1 and Article 7 requirements;therefore, it is important to review the referencing Code sectionrequirements when establishing the test procedure. Article 7 hasthree Mandatory Appendices: Mandatory Appendix I covers exam-ination of coated ferritic materials using the AC yoke technique,Mandatory Appendix II covers the definition of terms, andMandatory Appendix III covers examinations using the yoke tech-nique with fluorescent particles in an undarkened area.

20.9.1 Equipment The equipment selected must be capable of producing the nec-

essary magnetic flux in the part being examined, using the contin-uous method and one or more of the following techniques: prodtechnique, longitudinal and circular magnetization techniques,yoke technique, and multidirectional technique.

20.9.2 Examination Medium Dry, wet, visible, or fluorescent particles may be used in accor-

dance with the applicable technique selection. Article 25 containsSE-709, which provides specific requirements for all types of

particles and should be consulted when developing the test proce-dure. When using fluorescent particles, the examination must beperformed using an ultraviolet light (black light), and the exami-nation must be performed in a darkened area unless the require-ments of Mandatory Appendix III are met.

The black light shall have an intensity of 1000 mW/sq. cm at thesurface of the part; the light intensity shall be measured using ablack-light meter prior to and at the completion of examinationsplus any time the lights power supply is interrupted or changed. Itis important to maintain records of the intensity measurements andfrequency for subsequent audit verifications. Pretest requirementsfor use of the black light include a warm-up period of 5 min., andthe operator must be in the darkened area for 5 min. before startingthe examination to enable the inspectors eyes to adapt to darkviewing. Photosensitive eyeglass lenses are not permitted.

20.9.3 Surface Conditioning Surface conditioning is normally not necessary, and satisfactory

results can be obtained when surfaces are, for example, in the as-welded, as-rolled, as-forged, or as-cast condition; however, sur-face preparation by any mechanical means may be required if thesurface irregularities could mask indications. Before the examina-tion, the surface to be examined and adjacent areas within 1 in.shall be cleaned by any suitable means to ensure removal of extra-neous materials that could interfere with the examination. InArticle 7, paragraphs T-741.1 and T-741.2 provide additionalrequirements regarding cleaning and use of surface-contrastenhancement coatings for enhancing particle contrast.

20.9.4 Procedure/Technique The test procedure shall include at the very least the following

details:

(1) materials, shapes, and sizes to be examined and the extentof examination;

(2) magnetization technique used; (3) equipment used; (4) surface preparation (finishing and cleaning); (5) type of particles used; (6) magnetization current (type and amperage); (7) method of particle application; (8) method of excess particle removal; (9) minimum light intensity;

(10) coating thickness; (11) examination surface temperature; (12) post examination cleaning technique; (13) demagnetization; and (14) personnel qualification requirements.

20.9.5 Magnetic Field Adequacy and Direction A magnetic-particle field indicator (also called a pie gage or pie

indicator), described in Fig. T-764.1.7 (given here as Fig. 20.6),may be used when it is necessary to verify the adequacy or direc-tion of the magnetizing field. Because magnetic-particle fieldindicator is only permitted within the limitations prescribed forvarious magnetizing techniques, it is important to review Article7, paragraph T-764.3 for those limitations.

20.9.6 Rectified Current Whenever direct current is required, rectified current may be

used. The current shall be either three phase (full-wave rectified)or single phase (half-wave rectified).



20.9.7 Demagnetization Demagnetization is required when residual magnetization in

the part could interfere with subsequent processing or usage. Thedemagnetization can be performed at any time after completion ofthe examination.

20.9.8 Calibration of Equipment Test equipment with ammeters must be calibrated at least once

each year or whenever the equipment has been subjected to majorrepairs or overhaul. Article 7 provides details for the calibrationprocedure and tolerance values.

20.9.9 Lifting Power of Yokes The lifting power of yokes shall be checked annually or if the

yoke has been damaged. AC yokes must have a lifting power of10 lb. and DC permanent yokes must have a lifting power of 40lb. at maximum pole spacing.

20.9.10 Examination At least two separate examinations shall be performed on each

test area. For the second examination, the lines of flux should beapproximately perpendicular to those used for the first examina-tion. The examinations shall be conducted with sufficient overlapto ensure that 100% coverage is obtained. Article 7 provides spe-cific examination details for the five techniques previously men-tioned, and it is important to refer to the detailed requirements forthe specific technique that will be used for the examination.

20.9.11 Evaluation All indications shall be evaluated in accordance with the accep-

tance criteria in the applicable referencing Code section.

20.9.12 Records An examination record is required, documenting type of

equipment, magnetic particles, lighting equipment, and technique

used. Additional requirements are listed in paragraph T-793. Atechnique sketch is required only if the multidirectional tech-nique is used. The technique-sketch requirements are listed inparagraph T-791.

20.10 ARTICLE 8: EDDY-CURRENTEXAMINATION OF TUBULARPRODUCTS

This article covers the test method requirements for eddy-current examination of tubular products. The methods and techniques substantially conform to SE standard 243 found inArticle 26. SE-243 should be reviewed when developing the testprocedure. When eddy-current examination is required by a referencing Code section, Article 1 requirements also apply.There are six Mandatory Appendices that accompany Article 8:Appendix I,. Glossary of Terms for Eddy-Current Examination;Appendix II, Eddy-Current Examination of NonferromagneticHeat Exchanger Tubing; Appendix III, Eddy-Current Examinationon Coated Ferritic Materials; Appendix IV, External Coil EddyCurrent Examination of Tubular Products; Appendix V, EddyCurrent Measurement of Nonconductive-Nonmagnetic CoatingThickness on a Nonmagnetic Metallic Material; and AppendixVI, Eddy Current Detection and Measurement of Depth ofSurface Discontinuities in Nonmagnetic Metals with SurfaceProbes. Again, the applicable Mandatory Appendix requirementsshall be followed for the specific application.

20.10.1 General All eddy-current or electromagnetic examinations shall be per-

formed in accordance with a detailed written procedure unlessother provisions are stated in the referencing Code section.

20.10.2 Personnel Qualifications Personnel qualification requirements are as specified in the ref-

erencing Code section.

20.10.3 Procedure The procedure used for the examination shall ensure a sensitivi-

ty level at which indications equal to or greater than those obtainedfrom the reference standard are consistently detected. The writtenprocedure shall include at least the following information:

(1) frequency; (2) mode; (3) minimum fill factor; (4) type of coil or probe; (5) scanning speed and technique; (6) type of material and size(s); (7) reference standard notch or hole size; (8) equipment manufacturer/model; (9) scanning equipment;

(10) data recording equipment; (11) cable type and length; and (12) software used for acquisition/analysis.

20.10.4 Reference Standard The reference standard (reference specimen) shall be the same

as the parts being examined and processed in the same manner.The standard shall be of the same nominal diameter and samenominal composition as the parts being examined. Unless specifiedotherwise by the referencing Code section, the calibration reference

FIG. 20.6 MAGNETIC-PARTICLE FIELD INDICATOR(Source: T-764.1.1, Article 7, Section V of the

ASME B&PV Code)


18 Chapter 20

shall be transverse notches or drilled holes, as specified in Article26, SE-243. The standard shall be long enough to simulate thehandling of the part through the inspection system equipment.The separation between the reference notches or drilled holesplaced in the same reference standard should not be less thantwice the length of the sensing unit on the inspection system.

20.10.5 Calibration The inspection system shall be checked and verified by using

the reference standard as follows:

(1) at the beginning of each run of a given diameter and thick-ness;

(2) at the end of the production run; and (3) anytime there is an equipment malfunction. If at anytime during calibration or the production run it is deter-

mined that the equipment is not functioning properly, all of theproduct tested since the last valid calibration or verification shallbe reinspected.

20.10.6 Evaluation Examination test results shall be evaluated in accordance with

the requirements of the referencing Code section. As previously mentioned, there are six Mandatory Appendices

accompanying Article 8 that address specific applications. Usersshould be aware of these specific applications, as they may be rel-evant to the examination being performed.

20.11 ARTICLE 9: VISUAL EXAMINATION Appendix I, which is mandatory, accompanies Article 9 and

provides a glossary of terms. Article 9 requirements at this time are primarily invoked by

Section III. However, because it is good manufacturing practice toperform a visual examination to ensure product quality, usersshould become familiar with the requirements of Article 9 andapply visual examination as they see fit.

20.11.1 Written Procedure Requirements The examination shall be performed in accordance with a writ-

ten procedure prepared by the manufacturer. The manufacturershall make available the procedure and a list of the examinationsto be performed to the Authorized Inspector. The procedure shallinclude at least the following:

(1) equipment used for remote viewing (2) equipment used for direct viewing (3) personnel qualification requirements (4) methods and/or tools used for surface preparation; (5) whether direct or remote viewing will be used; (6) special illumination, instruments, or equipment used; (7) sequence of performing the operation, when applicable; (8) lighting intensity; (9) configuration to be examined; Procedures may be general or specific for a certain application.

The procedure shall contain or reference a report of the testmethod used to demonstrate the procedures adequacy. A fine line1/32 in. or less in width or a similar artificial flaw placed on thesurface at the least discernible location to be examined may beconsidered as a test method for the demonstration.

20.11.2 Physical Requirements Personnel performing visual examination shall have an annual

vision test to ensure natural or corrected near-distance acuity. Thetest consists of the candidate being able to read the J-1 letters onstandard Jaeger test charts. Equivalent tests may be used in lieu ofthe Jaeger test charts.

20.11.3 Procedure/Technique

20.11.3.1 Typical Applications The following several commonapplications of visual examination are used:

(1) to determine if surface conditions of the part satisfy the sur-face requirements;

(2) verification of alignment of mating surfaces; (3) verification of shapes; and (4) evidence of leaks during static or dynamic testing. 20.11.3.2 Techniques Techniques used are direct viewing,

remote viewing, and translucent examination. Specific require-ments for each technique are provided in the Article.

20.11.3.3 Evaluation All examination results shall be evaluatedin accordance with the criteria required by the referencing Code sec-tion. An examination checklist is required to plan the visual exami-nations and verify that visual observations have been completed.

20.11.3.4 Documentation and Records When required by thereferencing Code section a written report is made and shall bemaintained as required by that referencing Code section. Specificitems to be included in the report are listed in the Article.

20.12 ARTICLE 10: LEAK TESTING Article 10 consists of the general section, ten Mandatory

Appendices and one Nonmandatory Appendix. Most of theseAppendices cover specific types of tests, as follows:

Appendix I, Bubble Test (Direct Pressure Technique). Appendix II, Bubble Test (Vacuum Box Technique). Appendix III, Halogen Diode Detector Probe Test. Appendix IV, Helium Mass Spectrometer (Detector Probe

Technique). Appendix V, Helium Mass Spectrometer (Tracer Probe

Technique). Appendix VI, Pressure Change Test. Appendix VII, Glossary of Terms. Appendix VIII, Thermal Conductivity Detector Probe Test. Appendix IX, Helium Mass Spectrometer (Hood Technique). Appendix X, Ultrasonic Leak Detector Test. Appendix A, is Leak Testing Formula Symbols.

The requirements of the applicable Mandatory Appendix mustbe followed for the specific test technique being performed.

20.12.1 Procedure Written procedure requirements vary slightly according to tech-

nique. In general, the procedure shall include the following mini-mum information:

(1) extent of the examination; (2) type of equipment used for detecting leaks or measuring

leak rates;



(3) type of surface cleaning performed and equipment used; (4) method or technique of the test to be performed; and (5) temperature, pressure, gas, and % concentration to be used. The referencing Code section shall be consulted for additional

information concerning the following:

(1) personnel qualification/certification; (2) technique(s)/calibration standards; (3) extent of examination; (4) test sensitivity or leakage rate; and (5) report and records retention requirements.

20.12.2 Equipment (Gages) If dial indicating or recording pressure gages are used, the dial

should be graduated over a range of about double the intended orrequired pressure; however, in no case shall the gage be less than

or more than 4 times the required pressure. These limits do notapply to dial indicating and recording vacuum gages. Other gagerange requirements may be specified in the applicable MandatoryAppendix for the test technique being used. The gage location forpressure/vacuum leak testing shall be connected to the componentin a remote location, with the gage position readily visible to thetest operator throughout the duration of pressurizing, evacuating,testing, and depressurizing/venting. For large vessels or systems,a recording-type gage is recommended.

20.12.3 Requirements The surface(s) to be tested shall be clean and free of any conta-

minants; all openings shall be sealed using plugs, covers, or othersuitable material that can readily be removed after the test. Theminimum metal temperature for all components during a test shallbe as required in the referencing Code section. Components thatare pressure-leak-tested shall not be tested at a pressure exceeding25% of the design pressure unless specified otherwise by the ref-erencing Code section.

20.12.4 Technique Before performing a sensitive leak test method, it may be expe-

dient to perform a preliminary test to detect and eliminate grossleaks. It is recommended that leak testing be performed before therequired hydrostatic or hydropneumatic test.

20.12.5 Calibration All pressure/vacuum dial indicating or recording gages shall be

calibrated against either a standard deadweight tester, a calibratedmaster gage, or a mercury column, and recalibration shall be per-formed at least once a year when in use. All gages shall providean accuracy within the manufacturers listed accuracy values.Temperature-measuring devices shall also be calibrated in accor-dance with the applicable Mandatory Appendix or the referencingCode section. Permeation-type leak standards shall leak throughfused glass or quartz. The standard shall have a helium leak ratein the range of to std m3/sec. Capillary-typeleak standards shall be a calibrated halogen or helium capillaryleak through a tube. The standard shall have a leak rate of

to std m3/sec.

20.12.6 Evaluation The acceptance standards used for the test shall be as required

by the referencing Code section. The supplemental leak testing

1 * 10-51 * 10-4

1 * 10-101 * 10-6

112

formulas for calculating leak rates for the method or techniqueused are provided in the applicable Mandatory Appendices.

20.12.7 Documentation A test report shall contain the following minimum information:

(1) date of test; (2) name and certification level of operator; (3) test procedure number and revision; (4) test method or technique; (5) test results; (6) component identification; (7) instrument, calibrated leak standard, and material identifi-

cation; (8) test conditions, test pressure, and gas concentration; (9) gage(s) manufacturer, model, range, and identification;

(10) temperature-measuring device used and identificationnumber; and

(11) sketch showing method or technique setup.

20.12.8 Record Retention The test report must be maintained in accordance with the

requirement of the referencing Code section.

20.13 ACOUSTIC EMISSION EXAMINATION Articles 11, 12, and 13 address acoustic emission examination

methodology. To the best of the authors knowledge, to date noCode sections have adopted any of these articles. Section VIII hasapproved in Code Case 1968 the use of Article 12 for examina-tion of specific low-pressure containers, and Section XI hasapproved the use of Article 13 for a specific application. Usersshould refer to the Code Case listing for the respective Code sec-tions for the necessary details.

20.14 ARTICLE 11: ACOUSTIC EMISSIONEXAMINATION OF FIBER-REINFORCED PLASTIC VESSELS

Acoustic emission (AE) of fiber-reinforced plastic vessels fallsunder the jurisdiction of Section X. Several references to Article11 are found in Section X, including the following paragraphs:RQ-142 (acceptance test for qualifying Class II vessel design andfabrication), RT-111 (Article 11 provisions should be included inNDT Level II qualification), RT-521 (calibration of AE equip-ment), and several references in RT-620 (acceptance tests forClass II vessels). The article includes the following threeMandatory Appendices:

Appendix I, Instrumentation Performance Requirements. Appendix II, Instrument Calibration. Appendix III, Glossary of Terms.

20.14.1 General When this article is specified by a referencing Code section, the

methods and techniques shall be used together with Article 1.Discontinuities located by AE must be examined by other NDEmethods and the test results evaluated in accordance with theapplicable acceptance criteria.


20 Chapter 20

20.14.2 Requirements

20.14.2.1 Vessel Conditioning For tanks and vessels that havebeen previously stressed, the operating pressure or load must bereduced in accordance with the operating levels provided in T-1121.

20.14.2.2 Vessel Stressing Arrangements must be made tostress the vessel at the prescribed design pressure or load, and therate of application must be sufficient to expedite the examinationwith minimum extraneous noise.

20.14.2.3 Environmental Conditions Vessel and fluid temper-atures are critical and are listed for various conditions.

20.14.2.4 Noise Elimination Extraneous noise must be mini-mized because it may mask AE signals. Instrument settings shallbe as prescribed in Mandatory Appendix II.

20.14.2.5 Sensors The mounting of sensors is critical, and thearticle describes requirements for mounting sensors and frequencychannels required for both high and low frequencies.

20.14.2.6 Written Procedure The AE examination shall beperformed in accordance with a written procedure when requiredby the referencing Code section. The procedure shall include as aminimum the following information:

(1) materials and configurations to be examined, includingdimensions and product form;

(2) method for determining sensor locations; (3) sensor locations; (4) couplant; (5) sensor type, frequency, and location; (6) equipment type and frequency; (7) description of system calibration; (8) data to be recorded and method of recording; (9) report requirements;

(10) postexamination cleaning used; and (11) qualification of the examiners.

20.14.3 Additional Requirements The Article provides further extensive requirement details

addressing the following:

(1) equipment and supplies; (2) application requirements; (3) calibration; (4) evaluation; and (5) documentation. Users should thoroughly review these specific details when

preparing their test procedure. Nonmandatory Appendix A(Sensor Placement Guidelines) should also be reviewed.

20.15 ARTICLE 12: ACOUSTIC EMISSIONEXAMINATION OF METALLICVESSELS DURING PRESSURETESTING

This article describes the methodology for conductingthe AE examination of metallic vessels during acceptancepressure testing when specified by a referencing Code section.

There are three Mandatory Appendices accompanying thearticle:

Appendix I, Instrumentation Performance Requirements. Appendix II, Instrumentation Calibration and Cross-

Referencing. Appendix III, Glossary of Terms.

The referencing Code section should be consulted for the fol-lowing specific requirements:

(1) personnel qualification/certification; (2) extent of examination or volume(s) to be examined; (3) acceptance criteria; (4) report requirements; and (5) content of records and records retention. When this article is specified by a referencing Code section, it

is used together with Article 1.

20.15.1 General The objectives of the AE examination are to locate and monitor

emission sources caused by surface and internal discontinuities.All relevant indications caused by AE sources must be examinedand evaluated by other NDE methods.

20.15.2 Requirements

20.15.2.1 Vessel Stressing The referencing Code section shouldprovide the necessary detailed information to stress the vesselusing internal pressure.

20.15.2.2 Noise Reduction External noise sources should beminimized, and the noise level must be below the system examina-tion threshold.

20.15.2.3 Sensor Frequency Recommended sensor frequencyis provided in Nonmandatory Appendix B. Sensor mounting, con-tact, and location details are provided in the general section.

20.15.2.4 Written Procedure The examination shall be performed in accordance with a written procedure and, as a minimum,the procedure shall include the following:

(1) material and configurations to be examined; (2) background noise measurements; (3) sensor type, frequency, and manufacturer; (4) method of sensor attachment; (5) type of couplant; (6) instrument type and filter frequency; (7) sensor locations; (8) method used for sensor selection; (9) a description of system calibration(s);

(10) data to be recorded and method of recording; (11) postexamination cleaning used; (12) report requirements; and (13) qualification/certification of examiner(s).

20.15.3 Other Requirements The article provides additional specific requirement details on

application requirements, calibration, evaluation, and documenta-tion. Consequently, the article should be carefully reviewed whenthe user prepares the written procedure. Nonmandatory Appendix



A (Sensor Placement Guidelines) and Nonmandatory Appendix B(Supplemental Information for conducting AE Examinations)should also be reviewed when

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