ML12157A666

1501 - E118 - Welding Technology and Codes - 06 - Non-Destructive Examination

ML12157A666
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Issue date:	06/05/2012
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Non-Destructive Examination Module 6

Module 6 - Inspection Module 6 - Inspection 6A - Non-Destructive Examination (NDE) Overview 6A.1 - Visual Inspection (VT) 6A.2 - Liquid Penetrant Testing (PT) 6A.3 - Magnetic Particle Testing (MT) 6A.4 - Eddy Current Testing (ECT) 6A.5 - Radiographic Testing (RT) 6A.6 - Ultrasonic Testing (UT) 6A.7 - NDE Advancements 6A.8 - NDE Qualification 6B - Fitness-for-Service 6J - ASME Section XI - Rules for Inservice Inspection of Nuclear Power Plant Components 6-2

Module 6 - Inspection Module 6 Learning Objectives Familiarize participants with NDE methods and their advantages and limitations Flaw Definitions and Classifications NDE Process Selection Guidelines NDE Personnel Qualification Pre-Service Inspection (PSI)

In-Service Inspection (ISI) 6-3

Non-Destructive Evaluation Overview Module 6A

Module 6 - Inspection NDE Overview Definition of NDE The use of noninvasive techniques to determine the integrity of a material, component, or structure Quantitatively measure some characteristic of an object Ideal conditions NDE allows inspection or measurement without doing harm to the structure NDE enables engineers to relate inspection data to service conditions in a manner that allows prediction and/or prevention of failures 6-5

Module 6 - Inspection NDE Overview Methods of NDE Methods covered in this course Methods not covered Visual Testing (VT) Acoustic Emission (AE)

Liquid Penetrant Testing (PT) Leak Testing Magnetic Particle Testing (MT) Optical Inspection Eddy Current Testing (ECT) Optical Interferometry Radiographic Testing (RT) Shearography Ultrasonic Testing (UT) Holography Digital Image Enhancement Metrology Thermography Microwave 6-6

Module 6 - Inspection NDE Overview Review of Weld Defect Types Fabrication-related Associated with primary fabrication or repair Can be controlled by combination of metallurgical and welding process factors Use of appropriate inspection techniques is critical Service-related Occur upon exposure to service environment Generally mechanically or environmentally induced May result from remnant weld defects or metallurgical phenomena associated with the weld thermal cycle Inspection and design issues are important to control defect formation and monitor propagation

Module 6 - Inspection Weld Defects Review of Weld Defect Types Fabrication-Related Defects Lack-of-fusion (LOF)

Weld undercut Excessive overbead or drop through Lack of penetration (LOP) or incomplete penetration Slag inclusions Porosity, voids Craters, melt-through, spatter, arc-strikes, underfill Sugaring Oxidation of root pass Cracks Service-Related Damage Mechanisms Hydrogen-induced Corrosion and Corrosion-fatigue Fatigue Creep and creep-fatigue

Module 6 - Inspection NDE Overview Flaw Definitions and Classifications Volumetric Flaws Planar Flaws Porosity Seams Inclusions (e.g., Slag, Tungsten, etc.) Lamination Shrinkage Lack of bonding Holes and voids Forging/rolling lap Corrosion thinning/loss Casting shut Corrosion pitting Fatigue cracks Porosity Stress corrosion cracks Lack of fusion Incomplete penetration 6-9

Module 6 - Inspection NDE Overview NDE Process Selection and Guidelines Volumetric Flaws Planar Flaws Surface Breaking Surface Breaking Visual, Liquid Penetrant, or Visual Optical Inspection Near Surface Near Surface Magnetic Particle and Eddy Magnetic Particle and Eddy Current Current Microwave Microwave Ultrasonic Testing (internal Ultrasonic Testing (internal flaws) flaws) Acoustic Emission Radiography Thermography Thermography Near Surface Internal Surface Breaking 6-10

Module 6 - Inspection Welding Codes Overview ASME Section V -

NDE Method vs.Type of Defect 6-11

Module 6 - Inspection Welding Codes Overview ASME Section V -

NDE Method vs. Type of Defect 6-12

Module 6 - Inspection Welding Codes Overview ASME Section V Guidance on NDE Method vs.

Type of Defect 6-13

Module 6 - Inspection NDE Overview NDE Personnel Certification American Society for Nondestructive Testing (ASNT) www.asnt.org The British Institute of Non-Destructive Testing (PCN Cerification) www.bindt.org CSWIP Certification Scheme for Welding & Inspection Personnel www.cswip.com Natural Resources Canada www.nrcan-rncan.gc.ca/mms-smm/ndt-end/index-eng.htm 6-14

Module 6 - Inspection NDE Overview NDE Personnel Qualification Levels Personnel certification levels Level I Follow procedures and techniques approved by Level III Not allowed to interpret and evaluate for acceptance or rejection Supervised and guided by Level II or Level III Level II Performs, evaluates, and documents results in accordance with written procedure approved by Level III Guides and supervises Level I Level III Interprets codes, standards, and other contractual documents Develops procedures Conducts training and examination of NDT personnel Chooses the inspection method Level III approves procedures for technical adequacy 6-15

Module 6 - Inspection NDE Overview Performance Demonstration In some cases personnel must demonstrate performance on flawed samples prior to inspection Demonstrations are in addition to personnel certifications Performance demonstrations require specific levels of flaw detection and sizing on samples representative of components to be inspected 6-16

Module 6 - Inspection NDE Overview Inspection Types Construction Inspection Conducted during the fabrication of the component As designated per ASME Section III or other construction code Pre-service Inspection Conduct preoperational examinations prior to initial operation of equipment or a facility to establish a baseline condition As designated per ASME Section III or other construction code Inservice Inspection Subsequent examinations for comparison to original (PSI) condition to determine and indentify any changes or growth of a flaw As designated per ASME Section XI or other in-service inspection code 6-17

Visual Inspection Module 6A.1

Module 6 - Inspection Visual Inspection Introduction Four primary factors affect the quality of a visual inspection Quality of the detector (eye or camera)

Lighting conditions Capability to process the visual data Level of training and attention to detail 6-19

Module 6 - Inspection Visual Inspection Contrast Sensitivity Contrast sensitivity is a measure of how faded or washed out an object can be before it becomes indistinguishable from a uniform field The human eye can detect is about 2% of full brightness Contrast sensitivity varies with The size or spatial frequency of a feature The lighting conditions Whether the object is lighter or darker than the background Campbell, F. W. and Robson, J. G. (1968)

Application of Fourier analysis to the visibility of gratings. Journal of Physiology (London) Image Courtesy of Izumi Ohzawa, Ph.D. University of California School of Optometry 6-20

Module 6 - Inspection Visual Inspection Light Levels Under normal lighting conditions the eye has good visual acuity and is most sensitive to greenish yellow color, which has a wavelength around 555 nanometers (photopic curve)

At this very low light level, sensitivity to blue, violet, and ultraviolet is increased, but sensitivity to yellow and red is reduced 6-21

Module 6 - Inspection Visual Inspection Light Intensity Measurement Effective visual inspection requires adequate lighting Specification requirements for lighting should be reviewed prior to performing an inspection Light Intensity monitors like that shown to the right ensure that the specification is being followed 6-22

Module 6 - Inspection Visual Inspection Light Directionality The directionality of the light is a very important consideration For some applications, flat, even lighting works well For other applications, directional lighting is better because it produces shadows that are larger than the actual flaw and easier to detect 6-23

Module 6 - Inspection Visual Inspection Perspective The eye/brain need visual clues to determine perspective.

Is the book facing towards or away from you?

6-24

Module 6 - Inspection Visual Inspection Optical Illusions Sometime the eye/mind has trouble correctly processing visual information Are the horizontal lines parallel or How many black dots do you see?

do they slope?

6-25

Module 6 - Inspection Visual Inspection Basic Principles - Vision When evaluations are made by an inspector, eye examinations must be done at regular intervals to assure accuracy and sensitivity Near Vision (Jaeger)

Far Vision (Snellen)

Color Differentiation When using machine vision, different but similar performance checks must be performed 6-26

Module 6 - Inspection Visual Inspection Manual vs Automated Inspection Majority of visual inspections are completed by an inspector, but machine vision is becoming more common Inspector has ability to quickly adapt to a variety of lighting and other non-typical conditions, and ability to use other senses Machine vision inspection system has the ability to make very consistent and rapid inspections of specific details of a component 6-27

Module 6 - Inspection Visual Inspection Alignment & Distortion Visual inspection frequently involves checking materials and components for fit and alignment Many standards establish allowable tolerances for fit and distortion A fabricated girder is being inspected for distortion, sweep and web flatness 6-28

Module 6 - Inspection Visual Inspection Equipment Visual inspection equipment includes a variety of different tools Rulers, tape measures and spring type calipers Rigid or flexible borescopes Remote crawlers with cameras Many tools have been designed for specific applications such as the various weld gauges Some of the specialized tools such as crawlers have been designed to satisfy the inspection needs in applications where conventional techniques are not feasible 6-29

Module 6 - Inspection Visual Inspection Dimensional Conformance of Welds Palmgren gauge Fillet gauge set VWAC gauge Cambridge gauge 6-30

Module 6 - Inspection Visual Inspection Dimensional Conformance of Welds Throat measurement Leg size determination Convexity measurement using a Palmgren gauge with fillet gauge with VWAC gauge 6-31

Module 6 - Inspection Visual Inspection Dimensional Conformance of Welds Measurement of undercut depth with VWAC gauge 6-32

Module 6 - Inspection Visual Inspection Dimensional Conformance of Machined Parts The finished depth of a Small hole gauge used in machined mold is determined determining hole diameter with a depth micrometer 6-33

Module 6 - Inspection Visual Inspection Basic Measurements One of the most common tools used in visual inspection is the rule or scale Used to measure linear dimensions, when properly used will measure within 0.015-in. or 1/64-in. and smaller Rules are made in a variety lengths, widths, and thicknesses They are graduated in common fractions, decimal units, and metric units, or combinations of both The specific type of rule is typically chosen relative to the application 6-34

Module 6 - Inspection Visual Inspection Precision Measurements 6-35

Module 6 - Inspection Visual Inspection Transferring Gauges Transfer instruments are used to take measurements which are transferred to direct measurement devices They consist of calipers, dividers, telescoping gauges and small hole gauges 6-36

Module 6 - Inspection Visual Inspection Transferring Gauges 6-37

Module 6 - Inspection Visual Inspection Direct and Remote Visual Inspection Many codes refer to direct visual examination as a visual inspection Requires that access to the area is sufficient to place the eye within 24 inches of the surface Examined at an angle of not less than 30º to that surface If these requirements cannot be met, then remote visual inspection may be used Remote visual inspection may be accomplished with the use of a number of optical aids such as, mirrors, magnifiers, and rigid or flexible borescopes 6-38

Module 6 - Inspection Visual Inspection Optical Aids Mirrors are valuable aids in visual inspection; they allow the inspection of threaded and bored holes, inside surfaces of pipes and fittings, as well as many others Magnifiers assist by enlarging the size of the object being examined Comparators are a magnifier with a measuring capability The comparator has interchangeable reticles which provide measurements for threads, angles, linear measurement, diameters and radii 6-39

Module 6 - Inspection Visual Inspection Optical Aids Clean Surface Corrosion Damage 6-40

Module 6 - Inspection Visual Inspection Inspection Applications Applications for visual inspection range from looking a product over for obvious defect to performing detailed inspections Detection of surface anomalies such as scratches, excess surface roughness, and areas void of paint or plating Crack, porosity, corrosion or other flaw detection Dimensional conformance Precision measurements Foreign object detection Component location 6-41

Module 6 - Inspection Visual Inspection Flaw Detection Visual inspection of manufactured materials and components is a cost effective means of identifying flaws Visual inspection of a casting reveals a crack between a threaded opening and a pressed fit The aluminum sand casting has hot tears and shrinkage at the transition zones 6-42

Module 6 - Inspection Visual Inspection Flaw Detection In-service inspections of existing components and structures is commonly accomplished visually In this example, visual inspection of a fire escape reveals a failure in a handrail tube The failure is in the tube seam and is likely the result of ice expansion 6-43

Module 6 - Inspection Visual Inspection Flaw Detection Normal inspection practices for highway bridges rely almost entirely on visual inspection to evaluate the condition of the bridges Over 80 percent of all aircraft inspections are performed visually 6-44

Module 6 - Inspection Visual Inspection Flaw Detection Weld quality requirements are commonly determined through visual inspection Many standards have established acceptance criteria for welds Transverse weld crack Slag rolled into toe of weld 6-45

Module 6 - Inspection Visual Inspection Machine Vision Inspection 6-46

Module 6 - Inspection Visual Inspection Machine Vision - Equipment Key System Elements Common elements to all vision systems Front-end optics Frame grabber Processor Control software Other components can be included in a machine vision system, which depend on the environment, the application, and the budget 6-47

Module 6 - Inspection Visual Inspection Machine Vision - Applications Assembly verification Caps, fasteners, electronic board components, etc.

Surface inspection Dents, scratches, porosity, etc.

Verification of colors, gradients, patterns in fabrics and labels Confirmation of proper labeling for medications, foods and other products Inspection of coating coverage Assembly Verification Feature measurements Spark Gap Measurement 6-48

Module 6 - Inspection Visual Inspection ASME Section V Requirements ASME Section V, Article 9, Visual Examination T-920, General Requirements Lists the requirements for written procedures, procedure qualifications and demonstration reference Personnel requirements, physical requirements, equipment T-950, Techniques Describes different techniques used for visual inspection T-952, Direct Visual Examination T-953, Remote Visual Examination T-954, Translucent Visual Examination T-980, Evaluation Covers the evaluation requirements and references the code of construction ASME Section III or ASME B31.1 T-690, Documentation Describes the minimum requirements for the examination record Procedure and techniques used, examination personnel, map or record of indications, etc.

6-49

Module 6 - Inspection Visual Inspection ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Change from direct to or from translucent X Change from direct to remote X Remote visual aids X Personnel performance requirements, when required X Lighting intensity (decrease only) X Configurations to be examined and base material product forms (pipe, plate, forgings, etc.) X Lighting equipment X Methods or tools used for surface preparation X Equipment or devices used for a direct technique X Sequence of examination X Personnel qualifications X 6-50

Module 6 - Inspection Visual Inspection ASME Acceptance Requirements for Visual Inspection ASME B31.1 Section 136.4.2 provides visual examination acceptance criteria References ASME Section V, Article 9 ASME Section III, Division 1 - NB only gives visual acceptance criteria for brazed joints Indication ASME B31.1 Acceptance Criteria External Cracks Unacceptable External Undercut Greater than 1/32 in. deep Maximum limit ranges from 1/16 in. through 1/4 in. (depends on Weld Reinforcement material thickness and design temperature)

External Lack of Fusion Unacceptable Incomplete Penetration Unacceptable Linear Indication Greater than 3/16 in.

Any single indication greater than 3/16 in.

Surface Porosity Four or more indications separated by 1/16 in or less edge to edge 6-51

Module 6 - Inspection Visual Inspection Visual Inspection Summary Advantages Readily used on almost all materials Simple to perform Low in cost, (application dependent)

Relatively quick Results may be permanently recorded.

Can be automated Disadvantages Direct inspections are limited to surfaces only Indirect inspections require greater inspector knowledge and training Inspector dependent, knowledge of materials and processing, eye sight Standards (workmanship) may be difficult to obtain 6-52

Module 6 - Inspection Visual Inspection Visual Inspection Experience Is the fillet weld visually acceptable according to ASME B31.1?

Indication ASME B31.1 Acceptance Criteria External Cracks Unacceptable External Undercut Greater than 1/32-in. deep Weld Reinforcement Maximum thickness 3/32-in.

External Lack of Fusion Unacceptable Incomplete Penetration Unacceptable Linear Indication Greater than 3/16-in.

Any single indication greater than 3/16-in.

Four or more indications separated by 1/16-in. or less edge Surface Porosity to edge 6-53

Module 6 - Inspection Visual Inspection Visual Inspection Experience 6-54

Module 6 - Inspection Visual Inspection Visual Inspection Experience Convex weld Acceptable per this gauge Concave weld Not acceptable per this gauge 6-55

Liquid Penetrant Testing Module 6A.2

Module 6 - Inspection Liquid Penetrant Testing Examples of Liquid Penetrant Testing 6-57

Module 6 - Inspection Liquid Penetrant Testing How Does PT Work?

A liquid with high surface wetting characteristics is applied to the surface of a component under test The penetrant penetrates into surface breaking discontinuities via capillary action and other mechanisms Excess penetrant is removed from the surface and a developer is applied to pull trapped penetrant back to the surface With good inspection technique, visual indications of surface discontinuities present become apparent 6-58

Module 6 - Inspection Liquid Penetrant Testing What Makes PT Work?

Every step of the penetrant process is done to promote capillary action This is the phenomenon of a liquid rising or climbing when confined to small openings due to surface wetting properties of the liquid Plants and trees draw water up from the ground to their branches and leaves to supply their nourishment The human body has miles of capillaries that carry life sustaining blood to our entire body 6-59

Module 6 - Inspection Liquid Penetrant Testing What Can Be Inspected Via PT?

Almost any material that has a relatively smooth, non-porous surface on which discontinuities or defects are suspected 6-60

Module 6 - Inspection Liquid Penetrant Testing What Cannot be Inspected Via PT?

Components with rough surfaces, such as sand castings, that trap and hold penetrant Porous ceramics Wood and other fibrous materials Plastic parts that absorb or react with the penetrant materials Components with coatings that prevent penetrants from entering defects Defect indications become less distinguishable as the background noise level increases 6-61

Module 6 - Inspection Liquid Penetrant Testing What Types of Discontinuities Can Be Detected Via PT?

All defects that are open to the surface Rolled products - Cracks, seams, laminations Castings - Cold shuts, hot tears, porosity, blow holes, shrinkage Forgings - Cracks, laps, external bursts Welds - Cracks, porosity, undercut, overlap, lack of fusion, lack of penetration 6-62

Module 6 - Inspection Liquid Penetrant Testing Choices of Penetrant Materials Penetrant Types Flourescent Visible Method Water Washable Postemulsifiable - Lipophilic Solvent Removable Postemulsifiable - Hydrophilic Developer Form Dry Powder Wet, Water Soluble Wet, Water Suspendable Wet, Non-Aqueous 6-63

Module 6 - Inspection Liquid Penetrant Testing Sensitivity Levels Penetrants are also formulated to produce a variety of sensitivity levels The higher the sensitivity level, the smaller the defect that the penetrant system is capable of detecting The four sensitivity levels are:

Level 4 - Ultra-High Sensitivity Level 3 - High Sensitivity Level 2 - Medium Sensitivity Level 1 - Low Sensitivity As the sensitivity level increases, so does the number of nonrelevent indications Penetrant needs to be selected that will find the defects of interest but not produce too many nonrelevent indications.

6-64

Module 6 - Inspection Liquid Penetrant Testing Visible vs. Fluorescent PT Inspection can be performed using visible (or red dye) or fluorescent penetrant materials Visible PT is performed under white light while fluorescent PT must be performed using an ultraviolet light in a darkened area Fluorescent PT is more sensitive than visible PT because the eye is more sensitive to a bright indication on a dark background Sensitivity ranges from 1 to 4 6-65

Module 6 - Inspection Liquid Penetrant Testing Why is Visible Penetrant Red and Fluorescent Penetrant Green?

Visible penetrant is usually red because red stands out and provides a high level of contrast against a light background Fluorescent penetrant is green because the eye is most sensitive to the color green 6-66

Module 6 - Inspection Liquid Penetrant Testing Penetrant Removal Method Penetrants are also classified by the method of removing the excess penetrant Solvent removable Water washable Post-emulsifiable 6-67

Module 6 - Inspection Liquid Penetrant Testing Developers The role of the developer is to pull trapped penetrant out of defects and to spread it out on the surface so it can be seen Also provides a light background to increase contrast when visible penetrant is used 6-68

Module 6 - Inspection Liquid Penetrant Testing 6 Steps of Penetrant Testing

1. Pre-Clean

2. Penetrant Application

3. Excess Penetrant Removal

4. Developer Application

5. Inspect/Evaluate

6. Post-clean 6-69

Module 6 - Inspection Liquid Penetrant Testing Pre-Cleaning - Step 1 Parts must be free of dirt, rust, scale, oil, grease, etc. to perform a reliable inspection The cleaning process must remove contaminants from the surfaces of the part and defects, and must not plug any of the defects Pre-cleaning is the most important step in the PT process!!!

6-70

Module 6 - Inspection Liquid Penetrant Testing Penetrant Application - Step 2 There are many methods of application Brushing Spraying Dipping/Immersing Flow-on And more 6-71

Module 6 - Inspection Liquid Penetrant Testing Excess Penetrant Removal - Step 3 The removal technique depends upon the type of penetrant used, as stated earlier Solvent Removable Water Washable Post Emulsifiable 6-72

Module 6 - Inspection Liquid Penetrant Testing Developer Application - Step 4 The method of developer application is dependent on the type of developer used The primary methods for the main developer types will be covered in the following slides Dry Wet Nonaqueous Wet 6-73

Module 6 - Inspection Liquid Penetrant Testing Inspection/Evaluation - Step 5 In this step the inspector evaluates the penetrant indications against specified accept/reject criteria and attempts to determine the origin of the indication The indications are judged to be either relevant, non-relevant, or Non-relevant weld geometry false indications Relevant crack indications from an abusive drilling process 6-74

Module 6 - Inspection Liquid Penetrant Testing Post Clean - Step 6 The final step in the penetrant inspection process is to thoroughly clean the part that has been tested to remove all penetrant processing materials The residual materials could possibly affect the performance of the part or affect its visual appeal 6-75

Module 6 - Inspection Liquid Penetrant Testing Penetrant Inspection Systems 6-76

Module 6 - Inspection Liquid Penetrant Testing Verification of Penetrant System Performance Since penetrant testing involves multiple processing steps, the performance of the materials and the processes should be routinely checked using performance verification tools TAM Panels Crack Sensitivity Panels Run Check Panels 6-77

Module 6 - Inspection Liquid Penetrant Testing ASME Section V Requirements ASME Section V, Article 6, Liquid Penetrant Testing T-620, General Requirements Lists the requirements for written procedures and procedure qualifications T-640, Miscellaneous Requirements Include requirements for control of contaminants, surface preparation and drying after preparation T-650, Techniques Describes different techniques used for liquid penetrant testing Visible or flourescent Water washable, post-emulsifiying, or solvent removable Inspecting at nonstandard temperatures T-660, Calibration Covers the calibration requirements of the testing equipment 6-78

Module 6 - Inspection Liquid Penetrant Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Identification of and any change in type or family group of penetrant materials including developers, emulsifiers, etc. X Surface preparation (finishing and cleaning, including type of cleaning solvent) X Method of applying penetrant X Method of removing excess surface penetrant X Hydrophilic or lipophilic emulsifier concentration and dwell time in dip tanks and agitation time for hydrophilic emulsifiers X Hydrophilic emulsifiers concentration in spray applications X Method of applying developer X Minimum and maximum time periods between steps and drying aids X Decrease in penetrant dwell time X Increase in developer dwell time (Interpretation Time) X 6-79

Module 6 - Inspection Liquid Penetrant Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Minimum light intensity X Surface temperature outside 40ºF to 125ºF (5ºC to 52ºC) or as previously qualified X Performance demonstration, when required X Personnel qualification requirements X Materials, shapes, or sizes to be examined and the extent of examination X Post-examination cleaning technique X 6-80

Module 6 - Inspection Liquid Penetrant Testing ASME Section V Requirements ASME Section V, Article 6, Liquid Penetrant Testing T-670, Examination Lists the examination steps T-671, Penetrant Application T-672, Penetrant (Dwell) Time T-673, Excess Penetrant Removal T-675, Developing T-676, Interpretation T-677, Post-Examination cleaning 6-81

Module 6 - Inspection Liquid Penetrant Testing ASME Section V Requirements ASME Section V, Article 6, Liquid Penetrant Testing T-680, Evaluation Covers the evaluation requirements and references the code of construction ASME Section III or ASME B31.1 T-690, Documentation Defines what are considered rejectable and non-rejectable indications and describes the minimum requirements for the examination record Procedure used Liquid penetrant type and other equipment used Examination personnel Map or record of indications Material and thickness Date of examination 6-82

Module 6 - Inspection Liquid Penetrant Testing ASME Section III - NB and B31.1 Acceptance Requirements for Liquid Penetrant Testing Section NB-5350 of ASME Section III provides liquid penetrant examination acceptance criteria Section 136.4.4 of ASME B31.1 provides liquid penetrant examination acceptance criteria Both standards references ASME Section V, Article 6 Criteria ASME Section III - NB ASME B31.1 Crack or Linear Indication Unacceptable Any single indication greater than 3/16-in.

Four or more indications in a line separated by 1/16-in or less edge to edge Rounded Indications Ten or more indications in any 6-in2 of surface 6-83

Module 6 - Inspection Liquid Penetrant Testing Advantages of Liquid Penetrant Testing Relative ease of use Can be used on a wide range of material types Large areas or large volumes of parts/materials can be inspected rapidly and at low cost Parts with complex geometries are routinely inspected Indications are produced directly on surface of the part providing a visual image of the discontinuity Initial equipment investment is low Portable 6-84

Module 6 - Inspection Liquid Penetrant Testing Limitations of Liquid Penetrant Testing Only detects surface breaking defects Requires relatively smooth, nonporous material Precleaning is critical Contaminants can mask defects Requires multiple operations under controlled conditions Chemical handling precautions necessary (toxicity, fire, waste)

Metal smearing from machining, grinding and other operations inhibits detection Materials may need to be etched prior to inspection Post cleaning is necessary to remove chemicals 6-85

Magnetic Particle Testing Module 6A.3

Module 6 - Inspection Magnetic Particle Testing Examples of Magnetic Particle Testing 6-87

Module 6 - Inspection Magnetic Particle Testing Introduction to Magnetism Magnetism is the ability of matter to attract other matter to itself Magnetic lines of force can be found in and around the objects A magnetic pole is a point where a magnetic line of force exits or enters a material Magnetic lines of force Opposite poles attracting Similar poles repelling around a bar magnet 6-88

Module 6 - Inspection Magnetic Particle Testing Ferromagnetic Materials A material is considered ferromagnetic if it can be magnetized Materials with a significant iron (Fe), nickel (Ni), or cobalt (Co) content are generally ferromagnetic Ferromagnetic materials are made up of many regions (i.e.,

magnetic domains) in which the magnetic fields of atoms are aligned Magnetic domains point randomly in demagnetized material, but can be aligned using electrical current or an external magnetic field to magnetize the material S N Demagnetized Magnetized 6-89

Module 6 - Inspection Magnetic Particle Testing How Does MT Work?

A ferromagnetic test specimen is magnetized with a strong magnetic field created by a magnet or special equipment If the specimen has a discontinuity, the discontinuity will interrupt the magnetic field flowing through the specimen and a leakage field will occur 6-90

Module 6 - Inspection Magnetic Particle Testing Basic Procedure There are four basic steps in a magnetic particle testing procedure Component pre-cleaning Introduction of magnetic field Application of magnetic media Interpretation of magnetic particle indications 6-91

Module 6 - Inspection Magnetic Particle Testing Pre-Cleaning When inspecting a test part via MT, it is essential for the particles to have an unimpeded path for migration to both strong and weak leakage fields alike The parts surface should be clean and dry before inspection Contaminants such as oil, grease, or scale may not only prevent particles from being attracted to leakage fields, they may also interfere with interpretation of indications 6-92

Module 6 - Inspection Magnetic Particle Testing Introduction of the Magnetic Field The required magnetic field can be introduced into a component in a number of different ways Using a permanent magnet or an electromagnet that contacts the test piece Flowing an electrical current through the specimen Flowing an electrical current through a coil of wire around the part or through a central conductor running near the part 1 2 3 6-93

Module 6 - Inspection Magnetic Particle Testing Direction of the Magnetic Field Two general types of magnetic fields may be established within the specimen The type of magnetic field established is determined by the method used to magnetize the specimen Longitudinal magnetic field - magnetic lines of force run parallel to the long axis of the part Circular magnetic field - magnetic lines of force run circumferentially around the perimeter of the part 6-94

Module 6 - Inspection Magnetic Particle Testing Producing a Longitudinal Magnetic Field Using a Coil A longitudinal magnetic field is usually established by placing the part near the inside or a coils annulus This produces magnetic lines of force that are parallel to the long axis of the test part.

Coil on Wet Horizontal Inspection Unit Portable Coil 6-95

Module 6 - Inspection Magnetic Particle Testing Producing a Longitudinal Field Using Permanent or Electromagnetic Magnets Permanent magnets and electromagnetic yokes are often used to produce a longitudinal magnetic field The magnetic lines of force run from one pole to the other, and the poles are positioned such that any flaws present run normal to these lines of force 6-96

Module 6 - Inspection Magnetic Particle Testing Circular Magnetic Fields Circular magnetic fields are produced by passing current through the part or by placing the part in a strong circular magnet field A headshot on a wet horizontal test unit and the use of prods are several common methods of injecting current in a part to produce a circular magnetic field Placing parts on a central conductor carrying high current is another way to produce the field Magnetic Field Electric Current 6-97

Module 6 - Inspection Magnetic Particle Testing Application of Magnetic Media (Wet Versus Dry)

MT can be performed using either dry particles or particles suspended in a liquid With the dry method, the particles are lightly dusted onto the inspection surface With the wet method, the part is flooded with a solution carrying the particles Dry method is more portable Wet method is generally more sensitive since the liquid carrier gives the magnetic particles additional mobility 6-98

Module 6 - Inspection Magnetic Particle Testing Dry Magnetic Particles Magnetic particles come in a variety of colors A color that produces a high level of contrast against the background should be used 6-99

Module 6 - Inspection Magnetic Particle Testing Wet Magnetic Particles Wet particles are typically supplied as visible or fluorescent Visible particles are viewed under normal white light and fluorescent particles are viewed under black light 6-100

Module 6 - Inspection Magnetic Particle Testing Crane Hook with Service Induced Crack Wet Fluorescent Method 6-101

Module 6 - Inspection Magnetic Particle Testing Gear with Service Induced Crack Wet Fluorescent Method 6-102

Module 6 - Inspection Magnetic Particle Testing Drive Shaft with Heat Treatment Induced Crack Wet Fluorescent Method 6-103

Module 6 - Inspection Magnetic Particle Testing Splined Shaft with Service Induced Crack Wet Fluorescent Method 6-104

Module 6 - Inspection Magnetic Particle Testing Threaded Shaft with Service Induced Crack Wet Fluorescent Method 6-105

Module 6 - Inspection Magnetic Particle Testing Large Bolt with Service Induced Crack Wet Fluorescent Method 6-106

Module 6 - Inspection Magnetic Particle Testing Crank Shaft with Service Induced Crack Wet Fluorescent Method 6-107

Module 6 - Inspection Magnetic Particle Testing Lack of Fusion in SMAW Weld Visible, Dry Powder Method 6-108

Module 6 - Inspection Magnetic Particle Testing Toe Crack in SMAW Weld Visible, Dry Powder Method 6-109

Module 6 - Inspection Magnetic Particle Testing Throat and Toe Cracks in Partially Ground Weld Visible, Dry Powder Method 6-110

Module 6 - Inspection Magnetic Particle Testing Demagnetization Parts inspected by the magnetic particle method may sometimes have an objectionable residual magnetic field that may interfere with subsequent manufacturing operations or service of the component May interfere with welding and/or machining operation Can effect gauges that are sensitive to magnetic fields if placed in close proximity Abrasive particles may adhere to components surface and cause an increase in wear to engines components, gears, bearings etc.

For these reasons demagnetization maybe required 6-111

Module 6 - Inspection Magnetic Particle Testing ASME Section V Requirements ASME Section V, Article 7, Magnetic Particle Examination T-720, General Requirements Lists the requirements for written procedures and procedure qualifications T-730, Equipment Specifies the type of equipment needed as well as the particle type and temperature limitations T-740, Miscellaneous Requirements Include requirements for surface preparation and surface enhancement T-750, Techniques Describes different techniques used for magnetic particle testing T-752, Prod Technique T-753, Longitudinal Magnetization Technique T-754, Circular Magnetization Technique T-755, Yoke Technique T-756, Multidirectional Magnetization Technique 6-112

Module 6 - Inspection Magnetic Particle Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Magnetizing technique X Magnetizing current type or amperage outside range specified by this Article or as previously qualified X Surface preparation X Magnetic particles (fluorescent/visible, color, particle size, wet/dry) X Method of particle application X Method of excess particle removal X Minimum light intensity X Existing coatings, greater than the thickness demonstrated X Nonmagnetic surface contrast enhancement, when utilized X Performance demonstration, when required X 6-113

Module 6 - Inspection Magnetic Particle Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Examination part surface temperature outside of the temperature range recommended by the manufacturer of the particles or as previously qualified X Shape or size of the examination object X Equipment of the same type X Temperature (within those specified by manufacturer or as previously qualified) X Demagnetizing technique X Post-examination cleaning technique X Personnel qualification requirements X 6-114

Module 6 - Inspection Magnetic Particle Testing ASME Section V Requirements ASME Section V, Article 7, Magnetic Particle Examination T-760, Calibration Covers the calibration requirements of the testing equipment which includes checking magnetic field strength and orientation T-770, Examination Lists the examination steps T-772, Direction of Magnetization Specifes that the area to be tested shall be tested twice with the magnetic field of the second inspection perpendicular to the magnetic field of the first inspection T-773, Method of Examination T-774, Examination Coverage T-775, Rectified Current T-776, Excess Particle Removal T-777, Interpretation T-778, Demagnitization T-779 Post-Examination Cleaning 6-115

Module 6 - Inspection Magnetic Particle Testing ASME Section V Requirements ASME Section V, Article 7, Magnetic Particle Examination T-780, Evaluation Covers the evaluation requirements and references the code of construction ASME Section III or ASME B31.1 T-690, Documentation Defines what are considered rejectable and non-rejectable indications and describes the minimum requirements for the examination record Procedure used Magnetic particle equipment and current used Examination personnel Map or record of indications Material and thickness Date of examination 6-116

Module 6 - Inspection Magnetic Particle Testing ASME Section III - NB and B31.1 Acceptance Requirements for Magnetic Particle Testing Section NB-5340 of ASME Section III provides magnetic particle examination acceptance criteria Section 136.4.3 of ASME B31.1 provides magnetic particle examination acceptance criteria Both standards references ASME Section V, Article 7 Criteria ASME Section III - NB ASME B31.1 Crack or Linear Indication Unacceptable Any single indication greater than 3/16 in.

Four or more indications in a line separated by 1/16 in or less edge to edge Rounded Indications Ten or more indications in any 6 in2 of surface 6-117

Module 6 - Inspection Magnetic Particle Testing Advantages of Magnetic Particle Inspection Can detect both surface and VERY NEAR sub-surface defects Can inspect parts with irregular shapes easily Pre-cleaning of components is not as critical as it is for some other inspection methods. Most contaminants within a flaw will not hinder flaw detectability Fast method of inspection and indications are visible directly on the specimen surface Considered low cost compared to many other NDT methods Is a very portable inspection method especially when used with battery powered equipment 6-118

Module 6 - Inspection Magnetic Particle Testing Limitations of Magnetic Particle Inspection Cannot inspect non-ferrous materials such as aluminum, magnesium or most stainless steels Inspection of large parts may require use of equipment with special power requirements Some parts may require removal of coating or plating to achieve desired inspection sensitivity Limited subsurface discontinuity detection capabilities.

Maximum depth sensitivity is approximately 0.6 (under ideal conditions)

Post cleaning, and post demagnetization is often necessary Alignment between magnetic flux and defect is important 6-119

Eddy Current Testing Module 6A.4

Module 6 - Inspection Eddy Current Testing History 1879 - D. Hughes sorting of genuine and counterfeit coins 1881 - A. Bell induction sensing device for bullet in President J. Garfield (missed) 1933 - Kaiser-Wilhelm-Institute developed industrial system 1948 - Frster founded his own company in Reutlingen 1950 - F. Frster theory and instrumentation 1960 - proliferation of testing equipment Moore, P., Nondestructive Testing Handbook, third edition: Volume 5, Electromagnetic Testing, Columbus, OH, American Society for Nondestructive Testing, 2004 6-121

Module 6 - Inspection Eddy Current Testing Electromagnetic Induction Eddy currents are created through a process called electromagnetic induction When alternating current is applied to the conductor, such as copper wire, a magnetic field develops in and around the conductor This magnetic field expands as the alternating current rises to maximum and collapses as the current is reduced to zero 6-122

Module 6 - Inspection Eddy Current Testing Electromagnetic Induction If another electrical conductor is brought into the proximity of this changing magnetic field, the reverse effect will occur Magnetic field cutting through the second conductor will cause an induced current to flow in this second conductor Eddy currents are a form of induced currents Current Flow Current Flow 6-123

Module 6 - Inspection Eddy Current Testing Generation of Eddy Currents In order to generate eddy currents for an inspection a probe is used Inside the probe is an electrical conductor which is formed into a coil Alternating current is allowed to flow in the coil at a frequency chosen by the technician for the type of test involved A dynamic expanding and collapsing magnetic field forms in and around the coil as the alternating current flows through the coil 6-124

Module 6 - Inspection Eddy Current Testing Generation of Eddy Currents When an electrically conductive material is placed in the coils dynamic magnetic field electromagnetic, induction will occur and eddy currents will be induced in the material Eddy currents flowing in the material will generate their own secondary magnetic field which will oppose the change of coils primary magnetic field which will change the coil impedance 6-125

Module 6 - Inspection Eddy Current Testing Electricity - Alternating Current Impedance Capability of AC element or circuit to conduct AC current Vectorial representation Vectors (usually space related) l Z l= R 2 + X L2 or rather phasors (time related vectors) are used to represent currents, voltages and Impedance Modulus X L = L impedances in AC circuits Inductive 90 Reactance Imaginary Axis XL Imaginary Axis tan =

R Vm Phase Angle Calculated 0 from Vectorial Presentation

- Real Axis Im Moore, P., Nondestructive Testing Handbook, third edition: Volume 5, Electromagnetic Testing, Columbus, OH, American Society for Real Axis Nondestructive Testing, 2004 6-126

Module 6 - Inspection Eddy Current Testing Theory of EC - Depth of Penetration Variation of amplitude and phase of current Amplitude attenuates exponentially and phase changes linearly with depth in material Depth of standard penetration depends Current Density Amplitude vs Depth on material properties and frequency Defect signal with increasing depth Signal from identical defects at different depths will decrease Signal phase angle from defect will increase Flat Conductor 2 2 Y Induced = =

Current µ0 µ r µ0 Standard Depth of Standard Depth of X Standard Depth of Penetration Penetration for Penetration for Z Conductive Material Magnetic Material. Nonmagnetic Material 6-127

Module 6 - Inspection Eddy Current Testing Depth of Penetration Illustration Standard Depth of Depth Penetration Depth (Skin Depth) 1/e or 37 %

of surface density Eddy Current Density Eddy Current Density High Frequency Low Frequency High Conductivity Low Conductivity High Permeability Low Permeability Shallow Deep 6-128

Module 6 - Inspection Eddy Current Testing Geometric Flaw Characterization -

Current Interruption Hypothesis of interrupted currents Increased resistance Changed inductance Case of point defects Point defect will cause small interruption of eddy current contours if point defect size is relatively small compared to size of coil Case of large defects Larger defects will cause large interruption of eddy current contours and will easily be detected Interruption will also depend on defect orientation. If defect is parallel (delaminations) to EC contours it may be missed even if large Case of multiple defects Multiple defects will be easy to detect but may be difficult to separate 6-129

Module 6 - Inspection Eddy Current Testing ET Interaction with Flaw -

Current Interruption (3D View) 6-130

Module 6 - Inspection Eddy Current Testing ET Interaction with Flaw -

Current Interruption (2D View) 6-131

Module 6 - Inspection Eddy Current Testing Probes - Principles and Basic Characteristics Induction and reception functions Parametric Transformer Absolute and differential measure Absolute Differential Types of probes - parametric and transformer, absolute and differential, surface and encircling or internal, any combination of above.

6-132

Module 6 - Inspection Eddy Current Testing Probe Arrangements for Long Bars Parametric Absolute Transformer Absolute Transformer Absolute (Differential to Temperature and External EMN)

Parametric Differentia Self-comparison Parametric Absolute (Differential to Temperature and External EMN)

Transformer Differential MOVIE Self-comparison P - Primary Or Transmitter Encircling S - Secondary Or Receiver McMaster, R., Nondestructive Testing Handbook: Volume 2, Electromagnetic Testing, Columbus, OH, American Society for Nondestructive Testing, 1959 6-133

Module 6 - Inspection Eddy Current Testing Probe Arrangements for Plates, Sheets and Tubes Encircling Parametric Internal Parametric Surface Parametric Absolute Absolute Absolute MOVIE BobbinProbe Screen Transformer Screen Surface Parametric- Encircling Surface Transformer Absolute differential or Transformer- Transformer Absolute Absolute (Transmitter/ Receiver) Absolute Transmitter Transmitter Transmitter Receiver Receiver Receiver 6-134

Module 6 - Inspection Eddy Current Testing Different Probe Designs and Applications Surface spot probes Pencil probes Sliding and ring probes Bolt hole probes Encircling probes Internal or bobbin probes The Collaboration for NDT Education, www.ndt-ed.org 6-135

Module 6 - Inspection Eddy Current Testing Probes - EC Distributed Related to Coil Position Coil in Air Field generated by non-load inductor coil EC contours in the part related to juxtaposition between the coil Coil without Ferrite Magnetic Flux and the part Conductive Distance/Lift off effect on Material coupling in various probes Coil with Ferrite Core Focusing means Coil with Ferrite Cup Core Moore, P., Nondestructive Testing Handbook, third edition: Volume 5, Electromagnetic Testing, Columbus, OH, American Society for Nondestructive Testing, 2004 6-136

Module 6 - Inspection Eddy Current Testing Probes - Reaction of Different Coils According to Coil Shape Reaction to small flaws Reaction strongly depends on the ratio of flaw-to-probe size The higher the ratio the better the sensitivity to flaw but worse the sensitivity to lift off Differential probes with self-comparison are better for detection of small flaws than absolute Reaction to long flaws Long flaws are those that are longer than the diameter of surface or pencil probes or longer than the width of encircling/internal probes Differential probes will only indicate the begging and the end of long flaws whereas the absolute will indicate the entire length of long flaws Reaction to continuous (e.g. seam weld) flaws Absolute or self-comparison differential probes may not be adequate for this application May require differential arrangement with separate reference specimen 6-137

Module 6 - Inspection Eddy Current Testing Probes - Technology and Practical Characterization Critical design factors Manufacturing/design technology Electric parameters Maintenance Many factors possible to simulate through modeling 6-138

Module 6 - Inspection Eddy Current Testing Equipment - Different Types of EC Equipment Mono-parameter, mono-channel and specialized Multi-parameter and multi-channel Advantages of multi-parameter The Collaboration for NDT Education, www.ndt-ed.org 6-139

Module 6 - Inspection Eddy Current Testing Equipment - Auxiliary Devices Auxiliary devices for signal acquisition Driving mechanism, Saturating unit, Demagnetizer Equipment of signal storage System for automatic processing of signals The Collaboration for NDT Education, www.ndt-ed.org 6-140

Module 6 - Inspection Eddy Current Testing Materials and Products - Electromagnetic Properties Electric conductivity Chemical Temperature Grain size Texture Structure Magnetic permeability Chemical analysis 90 Temperature 80 Grain size µri 70 Texture 60 Structure 50 150 250 350 450 550 650 750 Normalization Temperature, degree C Moore, P., Nondestructive Testing Handbook, third edition: Volume 5, Electromagnetic Testing, Columbus, OH, American Society for Nondestructive Testing, 2004 6-141

Module 6 - Inspection Eddy Current Testing Materials and Products - Main Discontinuities Detected by EC Production - surface and slightly subsurface Solidification cracks Pores Chemical and phase composition Welding Processing (hot or cold)

Discontinuities Heat treatment Residual stresses and hardness Phase composition In-services Creep Fatigue Corrosion 6-142

Module 6 - Inspection Eddy Current Testing Influence of Parameters - Flaw Position and Orientation EC contours Contours must be as close to perpendicular to the flaw plane as possible to generate max response Penetration depth Best detection and sizing possible in one to two standard depth of penetrations Zone of probe action Non-shielded - Extends several depths of penetration around probe tip on inspected surface Shielded - Area around the probe is significantly reduced due to focusing ferrite and soft magnetic iron means 6-143

Module 6 - Inspection Eddy Current Testing Influence of Parameters - Material Temperature Heating - Temperature affects material properties Resistivity increases with the temperature increase Magnetic properties are lost above Curie temperature Local areas of spontaneous magnetization may appear on surface of hot rolled materials due to local cooling Compensation Differential and particularly transformer differential probes are best temperature compensated Probes may need cooling or must be cooled when testing materials after the furnace or hot rolling processing 6-144

Module 6 - Inspection Eddy Current Testing Influence of Parameters -

Geometry and Structure of Part Choice of test frequency Very important to optimize the operating point on the impedance plane diagram for best separation and sensitivity Phase discrimination Flaw depth measurements is better done with phase measurements in many cases Frequency selection important for better signal separation/discrimination by phase Filtering Reduces noise from fluctuating properties, vibration, electrical sources etc Magnetic saturation Used mainly for inspection of thin wall magnetic tubes as nonmagnetic (improved penetration) during saturation 6-145

Module 6 - Inspection Eddy Current Testing Influence of Parameters - Coupling Vibration Must be eliminated through mechanical means or filtered electronically Centering For encircling, internal tube and bolt hole probes, ensures the sensitivity is uniform along the tube or hole circumference Sensitivity Sensitivity is reduced when the coupling (usually increased distance) is reduced Compensation Use means for centering and stabilization of probe movement as close to inspected surface as possible Design probes less sensitive to coupling variations 6-146

Module 6 - Inspection Eddy Current Testing Influence of Parameters -

Speed Relative Part vs. Probe Defect spatial frequency (fdefect)

Examples of defect frequency at different inspection speeds Defect frequency of 100 Hz is obtained at testing speed of 0.3 m/s (1 ft/s) with probe Vtest diameter of 3 mm f defect =

Defect frequency of 1 kHz is obtained at Dcoil testing speed of 3 m/s (10 ft/s) with probe diameter of 3 mm Bandwith of equipment according to testing speed Bandwith is increased with increased inspection speed Further bandwidth increase is required when several probes are simultaneously used in multiplex arrangement Important to select adequate equipment for the expected inspection speeds Filter settings must be adjusted correctly for automated inspection applications 6-147

Module 6 - Inspection Eddy Current Testing Inspection Procedures - Reference Standards Reference standards are used to assure repeatability and provide acceptance criteria Choice of reference standards is very important Various types of reference Tube Standards EDM Notches (Crack Simulation) standards including fabrication, reproducibility types EDM notches Coating Standard Actual flaws Drilled holes or machined grooves Multipurpose - EDM Notches and Conductivity Corrosion Standard MOVIE The Collaboration for NDT Education, www.ndt-ed.org TubCalibrSpec 6-148

Module 6 - Inspection Eddy Current Testing Inspection Procedures - Inspection Access Surface preparation Speed Use of auxiliary devices Inspection range Indication recording 6-149

Module 6 - Inspection Eddy Current Testing Main Applications of EC Testing - Flaw Detection Absolute measurements Inspection for properties that change gradually (see slides with probe types)

Differential measurements Detection of relatively small and localized discontinuities (see slides with probe types) 6-150

Module 6 - Inspection Eddy Current Testing Main Applications of EC Testing -

Surface Flaw Detection MOVIE Surf&BoltholeProbe MOVIE MOVIE ThreadInsp WeldInspACFM One of the most wide-spread applications Conducted manually, semi- or fully-automated In many cases, superior to other surface inspection methods (LPI, MPI, UT)

Performed through paint, coatings or at a distance from surface 6-151

Module 6 - Inspection Eddy Current Testing Main Applications of EC Testing -

Tube Flaw Detection Typical inspection tasks Cracks, corrosion and other fabrication and service damage Renaissance of nuclear power plants will require more inspections Weld surface inspection MOVIE MOVIE TubInsp TubInspDiffer The Collaboration for NDT Education, www.ndt-ed.org 6-152

Module 6 - Inspection Eddy Current Testing Main Applications of EC Testing -

Coating Thickness Probe Aluminum Coating over Carbon Steel Coating

µC, C LO TC TS Substrate Paint over Aluminum and Carbon Steel

µS, S LO - Lift off TC - Coating thickness TS - Substrate thickness

µS, S - magnetic permeability and electrical conductivity of substrate

µC, C - magnetic permeability and electrical conductivity of coating Phasec D60 Manual 6-153

Module 6 - Inspection Eddy Current Testing Main Applications of EC Testing -

Material Sorting and Conductivity Impedance Plane Indications Set of Conductivity Specimens Common procedure for primary metal and Sorting of Ferromagnetic and automotive industries Nonferromagnetic Materials Performed manually, semi- or fully-automated Very reliable tool for heat treatment, case hardening depth, hardness, metal phase composition, stress and strain measurement and detection and other metal conditions Sorting of Nonferromagnetic Materials MOVIE Sorting Phasec D60 Manual 6-154

Module 6 - Inspection Eddy Current Testing ASME Section V Requirements ASME Section V, Article 8, Eddy Current Examination The section refers to different mandatory appendices depending on application Appendix II, Eddy Current Examination of Nonferromagnetic Heat Exchanger Tubing Appendix III, Eddy Current Examination on Coated Ferritic Materials Appendix IV, External Coil Eddy Current Examination of Tubular Products Appendix V, Eddy Current Measurement of Nonconductive-Nonmagnetic Coating Thickness on Nonmagnetic Metallic Material Appendix VI, Eddy Current Detection and Measurement of Depth of Surface Discontinuities in Nonmagnetic Metals with Surface Probes The format and requirements for all the appendices are similar Only covering Appendix II in example 6-155

Module 6 - Inspection Eddy Current Testing ASME Section V Requirements ASME Section V, Article 8, Appendix II, Eddy Current Examination of Nonferromagnetic Heat Exchanger Tubing II-820, General Requirements Lists the requirements for written procedures and procedure qualifications II-830, Equipment Describes different types of data acquisition systems and other equipment needed II-840, Requirements Include requirements for recording and sensitivity levels, probe speed, fixture location verification and automated eddy current data screens 6-156

Module 6 - Inspection Eddy Current Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Tube material X Tube diameter and wall thickness X Mode of inspection - differential or absolute X Probe type and size X Length of probe cable and probe extension cables X Probe manufacture, part number, and description X Examination frequencies, drive voltage, and gain settings X Manufacturer and model of eddy current equipment X Scanning direction during data recording, i.e., push or pull X Scanning mode - manual, mechanized probe driver, remote controlled fixture X Fixture location verification X 6-157

Module 6 - Inspection Eddy Current Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Identity of calibration reference standard(s) X Minimum digitization rate X Maximum scanning speed during data recording X Personnel requirements X Data recording equipment manufacturer and model X Scanning speed during insertion or retraction, no data recording X Side of application - inlet or outlet X Data analysis parameters X Tube numbering X Tube examination surface preparation X 6-158

Module 6 - Inspection Eddy Current Testing ASME Section V Requirements ASME Section V, Article 8, Appendix II, Eddy Current Examination of Nonferromagnetic Heat Exchanger Tubing II-860, Calibration Covers the calibration requirements and reference standards II-870, Examination II-880, Evaluation Covers the evaluation requirements and describes ways to determine flaw depth II-890, Documentation Defines indications and describes the minimum requirements for the examination record Procedure used Eddy current equipment used Examination personnel Record of indications Date of examination 6-159

Module 6 - Inspection Eddy Current Testing Advantages of Eddy Current Inspection Sensitive to small cracks and other defects Detects surface and near surface defects Inspection gives immediate results Equipment is very portable Method can be used for much more than flaw detection Minimum part preparation is required Test probe does not need to contact the part Inspects complex shapes and sizes of conductive materials 6-160

Module 6 - Inspection Eddy Current Testing Limitations of Eddy Current Inspection Only conductive materials can be inspected Surface must be accessible to the probe Skill and training required is more extensive than other techniques Surface finish and roughness may interfere Reference standards needed for setup In general, depth of penetration is limited Flaws such as delaminations that lie parallel to the probe coil winding and probe scan direction are undetectable 6-161

Radiographic Testing Module 6A.5

Module 6 - Inspection Radiographic Testing Electromagnetic Radiation 6-163

Module 6 - Inspection Radiographic Testing General Principles of Radiography The part is placed between the radiation source and a piece of film The part will stop some of the radiation Thicker and more dense areas will stop more of the radiation The film darkness (density) will vary with the amount of radiation reaching the film through the X-ray film test object Top view of developed film

= less exposure

= more exposure 6-164

Module 6 - Inspection Radiographic Testing General Principles of Radiography The energy of the radiation affects its penetrating power Higher energy radiation can penetrate thicker and more dense materials The radiation energy and/or exposure time must be controlled to properly image the region of interest Thin Walled Area Low Energy Radiation High Energy Radiation 6-165

Module 6 - Inspection Radiographic Testing Flaw Orientation Optimum Angle 0o 10o 20o 6-166

Module 6 - Inspection Radiographic Testing Radiation Sources Two of the most commonly used sources of radiation in industrial radiography are x-ray generators and gamma sources Industrial radiography is divided into X-ray radiography or gamma-radiography, depending on the source of radiation used 6-167

Module 6 - Inspection Radiographic Testing Gamma Radiography 6-168

Module 6 - Inspection Radiographic Testing Gamma Radiography 6-169

Module 6 - Inspection Radiographic Testing Gamma Radiography A drive cable is connected to the other end of the camera The drive cable, controlled by the radiographer, is used to force the radioactive material out into the guide tube where the gamma rays will pass through the specimen and expose the recording device 6-170

Module 6 - Inspection Radiographic Testing X-Ray Radiography 6-171

Module 6 - Inspection Radiographic Testing X-Ray Radiography The cathode contains a small filament much the same as in a light bulb High Electrical Potential Current passes through the filament which heats it, which causes electrons Electrons to be stripped off + -

The high voltage causes these free electrons to be pulled toward a target X-ray Generator or Radioactive Source material (usually made of tungsten) Creates Radiation located in the anode The electrons impact against the target causing an energy exchange which creates x-rays Radiation Penetrate the Sample Exposure Recording Device 6-172

Module 6 - Inspection Radiographic Testing Imaging Modalities Several different imaging methods are available to display the final image in industrial radiography:

Film Radiography Real Time Radiography (RTR)

Computed Radiography (CR)

Digital Radiography (DR)

Computed Tomography (CR) 6-173

Module 6 - Inspection Radiographic Testing Film Radiography One of the most widely used and oldest imaging mediums in industrial radiography is radiographic film Film contains microscopic material called silver bromide Once exposed to radiation and developed in a darkroom, silver bromide turns to black metallic silver, which forms the image 6-174

Module 6 - Inspection Radiographic Testing Film Radiography 6-175

Module 6 - Inspection Radiographic Testing Film Radiography Once developed, the film is referred to as a radiograph 6-176

Module 6 - Inspection Radiographic Testing Film Radiography The primary advantage of film radiography is high sensitivity There are several disadvantages Typically longer exposure times than digital Film processing time Waste disposal issues associated with silver and the film processing chemicals Storage of film Degradation of film over time 6-177

Module 6 - Inspection Radiographic Testing Digital Radiography One of the newest forms of radiographic imaging is Digital Radiography Requiring no film, digital radiographic images are captured using either special phosphor screens or flat panels containing micro-electronic sensors No darkrooms are needed to process film, and captured images can be digitally enhanced for increased detail Images are easily archived when in digital form 6-178

Module 6 - Inspection Radiographic Testing Digital Radiography Advantages Lower radiation levels required Image can be digitally enhanced to help with interpretation No degradation of image over time Ease of storage Disadvantages Typically lower sensitivity than film Fear factor of changing 6-179

Module 6 - Inspection Radiographic Testing Computed Radiography Computed Radiography (CR) is a digital imaging process that uses a phosphor imaging plate (PIP) instead of film 6-180

Module 6 - Inspection Radiographic Testing Computed Radiography X-rays penetrating the specimen stimulate the phosphors The stimulated phosphors remain in an excited state CR Phosphor Screen Structure X-Rays Protective Layer Phosphor Layer Phosphor Grains Substrate 6-181

Module 6 - Inspection Radiographic Testing Computed Radiography After exposure the imaging plate is read electronically and erased (via natural light) for re-use in a special scanner system 6-182

Module 6 - Inspection Radiographic Testing Computed Radiography Technique possible due to photostimulable luminescence (PSL)

PSL is a phenomenon in which a phosphor that has ceased emitting light, because of the removal of the stimulus, once again emits light when excited by light with a longer wavelength Optical Scanner Photo-multiplier Tube Laser Beam A/D Converter Imaging 110010010010110 Plate Motor 6-183

Module 6 - Inspection Radiographic Testing Computed Radiography Digital images are typically sent to a computer workstation where specialized software allows manipulation and enhancement 6-184

Module 6 - Inspection Radiographic Testing Computed Radiography Examples of computed radiographs:

6-185

Module 6 - Inspection Radiographic Testing Real-Time Radiography The equipment needed for Real-Time Radiography (RTR) includes:

X-ray tube Image intensifier or other real-time detector Camera Computer with frame grabber board and software Monitor Sample positioning system (optional) 6-186

Module 6 - Inspection Radiographic Testing Real-Time Radiography The image intensifier is a device that converts the radiation that passes through the specimen into light It uses materials that fluoresce when struck by radiation The more radiation that reaches the input screen, the more light that is given off The image is very faint on the input screen so it is intensified onto a small screen inside the intensifier where the image is viewed with a camera 6-187

Module 6 - Inspection Radiographic Testing Real-Time Radiography Comparing Film and Real-Time Radiography Real-time images are lighter Film images are darker in in areas where more X-ray areas where more X-ray photons reach and excite photons reach and ionize the fluorescent screen. the silver molecules in the film.

6-188

Module 6 - Inspection Radiographic Testing Direct Radiography Direct radiography (DR) is a form of real-time radiography that uses a special flat panel detector The panel works by converting penetrating radiation passing through the test specimen into minute electrical charges The panel contains many micro-electronic capacitors The capacitors form an electrical charge pattern image of the specimen Each capacitors charge is converted into a pixel which forms the image 6-189

Module 6 - Inspection Radiographic Testing Computed Tomography Computed Tomography (CT) uses a real-time inspection system employing a sample positioning system and special software 6-190

Module 6 - Inspection Radiographic Testing Computed Tomography Many separate images are saved and complied into 2-dimensional sections as the sample is rotated 2-D images are then combined into 3-D images Known as a CT or CAT scan in the medical field Real-Time Compiled 2-D Compiled 3-D Captures Images Structure 6-191

Module 6 - Inspection Radiographic Testing Image Quality 6-192

Module 6 - Inspection Radiographic Testing Image Quality Image quality for plaque IQIs is given as a combination of hole size and IQI thickness relative to the part thickness 2-2T is a common sensitivity level requirement This means that a plaque IQI having a thickness that is 2% of the part thickness shall be used and the IQI hole diameter that is 2 times the IQI thickness shall be visible in the radiograph ASTM E747 provides equivalent penetrameter sensitivity (EPS) levels for plaque IQIs and wire IQIs 6-193

Module 6 - Inspection Radiographic Testing Radiation Safety 6-194

Module 6 - Inspection Radiographic Testing Radiation Safety Technicians who work with radiation must wear monitoring devices that keep track of their total absorption, and alert them when they are in a high radiation area.

Survey Meter Pocket Dosimeter Radiation Alarm Radiation Badge 6-195

Module 6 - Inspection Radiographic Testing Radiation Safety There are three means of protection to help reduce exposure to radiation Time Distance Shielding 6-196

Module 6 - Inspection Radiographic Testing ASME Section V Requirements ASME Section V, Article 2, Radiographic Examination The section refers to different mandatory appendices depending on application 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 Results Produced by the Digital Image Acquisition and Display Process Appendix VI, Digital Image Acquisition, Display, Interpretation, and Storage of Radiographs for Nuclear Applications Appendix VII, Radiographic Examination of Metallic Castings Appendix VIII, Radiography using Phosphor Imaging Plate Appendix IX, Application of Digital Radiography There is a nonmandatory appendix the provides recommendations of radiographic techniques for pipe or tube welds 6-197

Module 6 - Inspection Radiographic Testing ASME Section V Requirements ASME Section V, Article 2, Radiographic Examination T-220, General Requirements Lists the requirements for written procedures, procedure qualifications, procedure demonstration, surface preparation, and backscatter radiation There are a minimum of seven requirements for a procedure Material and thickness range Isotope or maximum x-ray voltage Source to object distance Source size Film brand and designation Screens used T-230, Equipment and Materials Describes different types of equipment needed Specifies Image Quality Indicator (IQI) designs should be hole or wire type or equivalent 6-198

Module 6 - Inspection Radiographic Testing ASME Section V Requirements 6-199

Module 6 - Inspection Radiographic Testing ASME Section V Requirements ASME Section V, Article 2, Radiographic Examination T-260, Calibration Lists the calibration requirements including verifying the source size and densitometer or step wedge comparison file T-270, Examination Covers the different methods and requirements for examination T-271.1, Single-Wall Technique T-271.2, Double-Wall Technique T-274, Geometric Unsharpness T-275, Location Markers T-276, IQI Selection 6-200

Module 6 - Inspection Radiographic Testing ASME Section V Requirements 6-201

Module 6 - Inspection Radiographic Testing ASME Section V Requirements 6-202

Module 6 - Inspection Radiographic Testing ASME Section V Requirements 6-203

Module 6 - Inspection Radiographic Testing ASME Section V Requirements ASME Section V, Article 2, Radiographic Examination T-280, Evaluation Covers the evaluation requirements and describes ways to determine the quality of the radiograph T-281, Quality of Radiographs T-282, Radiographic Density T-283, IQI Sensitivity T-284, Excessive Backscatter T-290, Documentation Defines the minimum requirements for the examination record Procedure used Total number of radiographs Equipment used including source size and film Base material thickness, weld thickness, weld reinforcement thickness, etc.

Record of indications including location of markers Type of exposure 6-204

Module 6 - Inspection Radiographic Testing ASME Section III - NB and B31.1 Acceptance Requirements for Radiographic Testing Section NB-5320 of ASME Section III provides radiographic examination acceptance criteria Section 136.4.5 of ASME B31.1 provides radiographic examination acceptance criteria Both standards references ASME Section V, Article 2 6-205

Module 6 - Inspection Radiographic Testing ASME Section III - NB and B31.1 Acceptance Requirements for Radiographic Testing Criteria ASME Section III - NB ASME B31.1 Crack Unacceptable Zone of Incomplete Fusion Unacceptable 1/4 in. up to 3/4 in. t (weld thickness) 1/3t for t from 3/4 to 2 1/4 in.

Elongate Indication 3/4 in. for t over 2 1/4 in.

Any abrupt change in density of image brightness Internal Root Condition No elongated indications as defined above Aligned Indications Aggregrate length greater than t in a 12t length Any single indication greater than 1/4t or 5/32 in whichever is smaller Any single indication greater than 1/3t or 1/4 in whichever is smaller for indications 1 in. or more apart Round Indications For t > 2 in. the maximum indication is 3/8 6-206

Module 6 - Inspection Radiographic Testing Advantages of Radiography Technique is not limited by material type or density Can inspect assembled components Minimum surface preparation required Sensitive to changes in thickness, corrosion, voids, cracks, and material density changes Detects both surface and subsurface defects Provides a permanent record of the inspection 6-207

Module 6 - Inspection Radiographic Testing Limitations of Radiography Many safety precautions for the use of high intensity radiation Many hours of technician training prior to use Access to both sides of sample required Orientation of equipment and flaw can be critical Determining flaw depth is impossible without additional angled exposures Expensive initial equipment cost 6-208

Ultrasonic Testing Module 6A.6

Module 6 - Inspection Ultrasonic Testing Basic Principles of Sound Sound is produced by a vibrating body and travels in the form of a wave Sound waves travel through materials by vibrating the particles that make up the material The pitch of the sound is determined by the frequency of the wave (vibrations or cycles completed in a certain period of time)

Ultrasound is sound with a pitch too high to be detected by the human ear 6-210

Module 6 - Inspection Ultrasonic Testing Basic Principles of Sound Ultrasonic waves are very similar to light waves in that they can be reflected, refracted, and focused In solid materials, the vibrational energy can be split into different wave modes when the wave encounters an interface at an angle other than 90-degrees Ultrasonic reflections from the presence of discontinuities or geometric features enables detection and location The velocity of sound in a given material is constant and can only be altered by a change in the mode of energy 6-211

Module 6 - Inspection Ultrasonic Testing Frequency Since sound is a series of vibrations, one way of measuring it is to count the number of vibrations per second, which is frequency Unit of measurement is Hertz (Hz) 1 Hz = 1 cycle/s 1,000 Hz = 1 KHz = 1,000 cycles/s 1,000,000 Hz = 1 MHz = 1,000,000 cycles/s 6-212

Module 6 - Inspection Ultrasonic Testing Typical Sound Velocities & Wavelengths LONGITUDINAL SHEAR Material Velocity Wavelength @ 5 MHz Velocity Wavelength @ 5 MHz M/s in./µs (mm) (in.) M/s in./µs (mm) (in.)

Air 330 0.013 0.07 0.003 --- --- --- ---

Aluminum 6300 0.248 1.26 0.050 3100 0.122 0.62 0.024 Copper 4660 0.183 0.93 0.037 2260 0.089 0.45 0.018 Plexiglass 2700 0.106 0.54 0.021 1100 0.043 0.22 0.009 Rexolite 2330 0.092 0.47 0.018 1100 0.043 0.22 0.009 Carbon Steel 5900 0.232 1.18 0.046 3230 0.127 0.65 0.025 Titanium 6100 0.240 1.22 0.048 3100 0.122 0.62 0.024 Water 1480 0.058 0.30 0.012 --- --- --- ---

6-213

Module 6 - Inspection Ultrasonic Testing Wavelength Wavelength is the distance from one point to the next identical point along a repetitive waveform It is dependent upon the material sound velocity and the transducer frequency V

Wavelength () = Velocity/Frequency or =

F Typical wavelength Wavelength of 200 Hz sound in air = 332/200 = 1.66 m Wavelength of 2 MHz compression wave in steel = 5,920/2,000,000 =

2.96 mm Wavelength of 2 MHz shear wave in steel = 3,250/2,000,000 = 1.63 mm 6-214

Module 6 - Inspection Ultrasonic Testing Wavelength Wavelength Amplitude (mV)

Time (micro seconds) 6-215

Module 6 - Inspection Ultrasonic Testing Effects of Wavelength in UT Shorter wavelengths can detect smaller flaws Therefore, shear waves of a given frequency will be capable of detecting smaller flaws in a material than compression waves Discontinuities of a size less than /2 may not be detected Shorter wavelengths attenuate quicker and therefore do not penetrate thicker material as well as long wavelengths would 6-216

Module 6 - Inspection Ultrasonic Testing Ultrasound Generation Ultrasound is generated with a transducer A piezoelectric element in the transducer converts electrical energy into mechanical vibrations (sound), and vice versa 6-217

Module 6 - Inspection Ultrasonic Testing Principles of Ultrasonic Inspection Ultrasonic waves are introduced into a material where they travel in a straight line and at a constant speed until they encounter a surface.

At surface interfaces some of the wave energy is reflected and some is transmitted.

The amount of reflected or transmitted energy can be detected and provides information about the size of the reflector.

The travel time of the sound can be measured and this provides information on the distance that the sound has traveled.

6-218

Module 6 - Inspection Ultrasonic Testing Test Techniques - Pulse-Echo In pulse-echo testing, a transducer sends out a pulse of energy and the same or a second transducer listens for reflected energy (an echo)

Reflections occur due to the presence of discontinuities and the surfaces of the test article The amount of reflected sound energy is displayed versus time, which provides the inspector information about the size and the location of features that reflect the sound initial pulse back surface echo crack echo crack plate 0 2 4 6 8 10 UT Instrument Screen 6-219

Module 6 - Inspection Ultrasonic Testing Test Techniques - Pulse-Echo Digital display showing signal generated from sound reflecting off back surface Digital display showing the presence of a reflector midway through material, with lower amplitude back surface reflector The pulse-echo technique allows testing when access to only one side of the material is possible, and it allows the location of reflectors to be precisely determined 6-220

Module 6 - Inspection Ultrasonic Testing Test Techniques - Through Transmission Two transducers located on opposing sides of the test specimen are used. 11 One transducer acts as a transmitter, the other T R as a receiver Discontinuities in the sound path will result in a partial or total loss of sound being T R transmitted and be indicated by a decrease 2 in the received signal amplitude Through transmission is useful in detecting discontinuities that are not good reflectors, 11 and when signal strength is weak It does not provide depth information 2

0 2 4 6 8 10 6-221

Module 6 - Inspection Ultrasonic Testing Test Techniques - Through Transmission Digital display showing received sound through material thickness Digital display showing loss of received signal due to presence of a discontinuity in the sound field 6-222

Module 6 - Inspection Ultrasonic Testing Test Techniques - Normal and Angle Beam In normal beam testing, the sound beam is introduced into the test article at 90º to the surface In angle beam testing, the sound beam is introduced into the test article at some angle other than 90º The choice between normal and angle beam inspection usually depends on:

The orientation of the feature of interest Obstructions on the surface of the part that must be worked around 6-223

Module 6 - Inspection Ultrasonic Testing Effect of Flaw Orientation and Beam Angle 6-224

Module 6 - Inspection Ultrasonic Testing Distance Amplitude Correction (DAC) 6-225

Module 6 - Inspection Ultrasonic Testing Sizing Weld Discontinuities Determining Weld Discontinuity Length Dimension 6-226

Module 6 - Inspection Ultrasonic Testing Inspection Applications There are numerous applications for which UT may be employed Flaw detection (cracks, inclusions, porosity, etc.)

Erosion & corrosion thickness gauging Assessment of bond integrity in adhesively joined and brazed components Estimation of void content in composites and plastics Measurement of case hardening depth in steels Estimation of grain size in metals 6-227

Module 6 - Inspection Ultrasonic Testing Relative Difficulty of Discontinuity Detection Using UT Type of Discontinuity Easy Difficult Porosity (isolated)

Porosity (cluster)

Porosity (elongated)

Slag (scattered, globular)

Slag (elongated)

Cracks (subsurface)

Incomplete joint penetration Cracks (surface)

Incomplete fusion 6-228

Module 6 - Inspection Ultrasonic Testing Thickness Gauging Ultrasonic thickness gauging is routinely utilized in the petrochemical and utility industries to determine various degrees of corrosion/erosion Applications include piping systems, storage and containment facilities, and pressure vessels 6-229

Module 6 - Inspection Ultrasonic Testing Flaw Detection - Delaminations Contact, pulse-echo inspection for delaminations on 36 rolled beam Signal showing multiple back surface echoes in an unflawed area Additional echoes indicate delaminations in the member 6-230

Module 6 - Inspection Ultrasonic Testing Flaw Detection in Welds One of the most widely used methods of inspecting weldments is ultrasonic inspection Full penetration groove welds lend themselves readily to angle beam shear wave examination 6-231

Module 6 - Inspection Ultrasonic Testing Equipment Equipment for ultrasonic testing is very diversified and proper selection is important to insure accurate inspection data as desired for specific applications UT systems are generally comprised of three basic components Instrumentation Transducers Calibration Standards 6-232

Module 6 - Inspection Ultrasonic Testing Transducers Transducers are manufactured in a variety of forms, shapes, and sizes for varying applications Transducers are categorized in a number of ways which include:

Contact or immersion Single or dual element Normal or angle beam In selecting a transducer, it is important to choose the desired frequency, bandwidth, size, and in some cases focusing, which optimizes the inspection capabilities 6-233

Module 6 - Inspection Ultrasonic Testing Probe Selection Factors to be considered:

Test object thickness Test object diameter Surface condition Metallurgical condition, e.g., grain size Type, position, and orientation of likely discontinuities Flaw sizing accuracy (beam should be smaller than flaw) 6-234

Module 6 - Inspection Ultrasonic Testing Contact Transducers Contact transducers are designed to withstand rigorous use and usually have a wear plate on the bottom surface to protect the piezoelectric element from contact with the surface of the test article Many incorporate ergonomic designs for ease of grip while scanning along the surface 6-235

Module 6 - Inspection Ultrasonic Testing Contact Transducers Contact transducers with two piezoelectric crystals in one housing are called dual element transducers One crystal acts as a transmitter, the other as a receiver This arrangement improves near surface resolution because the second transducer does not need to complete a transmit function before listening for echoes Dual elements are commonly employed in thickness gauging of thin materials 6-236

Module 6 - Inspection Ultrasonic Testing Angle Beam Transducers Angle beam transducers incorporate wedges to introduce a refracted shear wave into a material The incident wedge angle is used with the material velocity to determine the desired refracted shear wave according to Snells Law Transducers can use fixed or variable wedge angles Common application is in weld examination 6-237

Module 6 - Inspection Ultrasonic Testing Immersion Transducers Immersion transducers are designed to transmit sound whereby the transducer and test specimen are immersed in a liquid coupling medium (usually water)

Immersion transducers are manufactured with planar, cylindrical or spherical acoustic lenses (focusing lens) 6-238

Module 6 - Inspection Ultrasonic Testing Instrumentation Ultrasonic equipment is usually purchased to satisfy specific inspection needs Some users may purchase general purpose equipment to fulfill a number of inspection applications Test equipment can be classified in a number of different ways Portable or stationary Contact or immersion Manual or automated Further classification of instruments commonly divides them into four general categories D-meters Flaw detectors Industrial Special application 6-239

Module 6 - Inspection Ultrasonic Testing Instrumentation D-Meters D-meters or digital thickness gauge instruments provide the user with a digital readout They are designed primarily for corrosion/

erosion inspection applications Some instruments provide the user with both a digital readout and a display of the signal A distinct advantage of these units is that they allow the user to evaluate the signal to ensure that the digital measurements are of the desired features 6-240

Module 6 - Inspection Ultrasonic Testing Instrumentation Flaw Detectors Flaw detectors are instruments designed primarily for the inspection of components for defects However, the signal can be evaluated to obtain other information such as material thickness values Both analog and digital display Offer the user options of gating horizontal sweep and amplitude threshold 6-241

Module 6 - Inspection Ultrasonic Testing Instrumentation Flaw Detectors Industrial flaw detection instruments provide users with more options than standard flaw detectors May be modulated units allowing users to tailor the instrument for their specific needs Generally not as portable as standard flaw detectors 6-242

Module 6 - Inspection Ultrasonic Testing Instrumentation Immersion System Immersion ultrasonic scanning systems are used for automated data acquisition and imaging They integrate an immersion tank, ultrasonic instrumentation, a scanning bridge, and computer controls The signal strength and/or the time-of-flight of the signal is measured for every point in the scan plan The value of the data is plotted using colors or shades of gray to produce detailed images of the surface or internal features of a component 6-243

Module 6 - Inspection Ultrasonic Testing Calibration Standards Calibration is a operation of configuring the ultrasonic test equipment to known values Calibration provides the inspector with a means of comparing test signals to known measurements Calibration standards come in a wide variety of material types, and configurations due to the diversity of inspection applications Calibration standards are typically manufactured from materials of the same acoustic properties as those of the test articles 6-244

Module 6 - Inspection Ultrasonic Testing Calibration Standards Thickness calibration standards may Step Wedges be flat or curved for pipe and tube applications, consisting of simple variations in material thickness Distance/Area Amplitude standards utilize flat bottom holes (FBH) or side ASTM Distance/Area Amplitude drilled holes (SDH) to establish a known reflector size with changes in sound path from the entry surface NAVSHIPS Cal Block Side Drilled Holes 6-245

Module 6 - Inspection Ultrasonic Testing Data Presentation Information from ultrasonic testing can be presented in a number of differing formats Three of the more common formats include:

A-scan B-scan C-scan 6-246

Module 6 - Inspection Ultrasonic Testing Data Presentation - A-Scan A-scan presentation displays the amount of received ultrasonic energy Signal Amplitude as a function of time Relative discontinuity size can be estimated by comparing the signal amplitude to that from a known reflector Time Reflector depth can be determined by the position of the signal on the Signal Amplitude horizontal sweep Time 6-247

Module 6 - Inspection Ultrasonic Testing Data Presentation - B-scan B-scan presentations display a profile view (cross-sectional) of a test specimen Only the reflector depth in the cross-section and the linear dimensions can be determined A limitation to this display technique is that reflectors may be masked by larger reflectors near the surface 6-248

Module 6 - Inspection Ultrasonic Testing Data Presentation - C-Scan The C-scan presentation displays a plan type view of the test specimen and discontinuities C-scan presentations are produced with an automated data acquisition system, such as in immersion scanning Use of A-scan in conjunction with C-scan is necessary when depth determination is desired Photo of a Composite C-Scan Image of Component Internal Features 6-249

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements ASME Section V, Article 4, Ultrasonic Examination Methods for Welds The section refers to different mandatory appendices depending on equipment and technique applied Appendix I, Screen Height Linearity Appendix II, Amplitude Control Linearity Appendix III, Time of Flight Diffraction (TOFD) Technique Appendix IV, Phased Array Manual Raster Examination Techniques Using Linear Arrays There is a nonmandatory appendix the provides recommendations for calibration including calibration blocks, recording data and interpretation 6-250

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements ASME Section V, Article 4, Ultrasonic Examination Methods for Welds T-420, General Requirements Lists the requirements for written procedures and procedure qualifications T-430, Equipment Describes different types of equipment T-433, Couplant T-434 Calibration Blocks T-440, Miscellaneous Requirements Defines how to identify the weld locations, how to mark the welds and generate a reference point T-450, Techniques Describes different types of examination techniques and defines the terms straight beam and angle beam T-460, Calibration Lists the calibration requirements and the equipment linearity checks that need to be performed 6-251

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Weld configuration to be examined, including thickness dimensions and base material product form (pipe, plate, etc.) X The surfaces from which the examination shall be performed X Technique(s) (straight beam, angle beam, contact, and/or immersion) X Angle(s) and mode(s) of wave propagation in the material X Search unit type(s), frequency(ies), and element size(s)/shape(s) X Special search units, wedges, shoes, or saddles, when used X Ultrasonic instrument(s) X Calibration [calibration block(s) and technique(s)] X Direction and extent of scanning X Scanning (manual vs. automatic) X 6-252

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements Essential Nonessential Requirement (as applicable) Variable Variable Method for discriminating geometric from flaw indications X Method for sizing indications X Computer enhanced data acquisition, when used X Scan overlap (decrease only) X Personnel performance requirements, when required X Personnel qualification requirements X Surface condition (examination surface, calibration blocks) X Couplant: brand name or type X Automatic alarm and/or recording equipment, when applicable X Records, including minimum calibration data to be recorded (e.g., instrument settings) X 6-253

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements 6-254

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements 6-255

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements ASME Section V, Article 4, Ultrasonic Examination Methods for Welds T-470, Examination Covers the different technique and requirements for examination T-471, General Examination Requirements T-472, Weld Joint Distance Amplitude Technique T-473, Cladding Technique T-274, Non-Distance Amplitude Technique T-480, Evaluation Covers the evaluation requirements and describes techniques used to evaluate the reflectors 6-256

Module 6 - Inspection Ultrasonic Testing ASME Section V Requirements ASME Section V, Article 4, Ultrasonic Examination Methods for Welds T-490, Documentation Defines what are considered non-rejectable and rejectable indications Refers to the code of construction Specifies the minimum requirements for the examination record Procedure used including beam angles Equipment used any special equipment Calibration block used Map or record of rejectable indications Examination personnel Date of examination 6-257

Module 6 - Inspection Ultrasonic Testing ASME Section III - NB and B31.1 Acceptance Requirements for Ultrasonic Testing Section NB-5330 of ASME Section III provides ultrasonic examination acceptance criteria Section 136.4.6 of ASME B31.1 provides ultrasonic examination acceptance criteria Both standards references ASME Section V, Article 4 6-258

Module 6 - Inspection Ultrasonic Testing ASME Section III - NB and B31.1 Acceptance Requirements for Radiographic Testing Criteria ASME Section III - NB ASME B31.1 Crack Unacceptable Lack of Fusion Unacceptable Incomplete Penetration Unacceptable Indication greater than 20 % and length 1/4 in. up to 3/4 in. t (weld thickness)

Indication greater than 20 % and length 1/3t for t from 3/4 to 2 1/4 in.

Indication greater than 20 % and length 3/4 in. for t over Indication 2 1/4 in.

6-259

Module 6 - Inspection Ultrasonic Testing Advantage of Ultrasonic Testing Sensitive to both surface and subsurface discontinuities Depth of penetration for flaw detection or measurement is superior to other methods Only single-sided access is needed when pulse-echo technique is used High accuracy in determining reflector position and estimating size and shape Minimal part preparation required Electronic equipment provides instantaneous results Detailed images can be produced with automated systems Has other uses such as thickness measurements, in addition to flaw detection 6-260

Module 6 - Inspection Ultrasonic Testing Limitations of Ultrasonic Testing Surface must be accessible to transmit ultrasound Skill and training is more extensive than with some other methods Normally requires a coupling medium to promote transfer of sound energy into test specimen Materials that are rough, irregular in shape, very small, exceptionally thin or not homogeneous are difficult to inspect Cast iron and other coarse grained materials are difficult to inspect due to low sound transmission and high signal noise Linear defects oriented parallel to the sound beam may go undetected Reference standards are required for both equipment calibration, and characterization of flaws 6-261

NDE Advancements Module 6B

Module 6 - Inspection NDE Advancements NDE Modeling Modeling and simulation offers significant flexibility and cost reduction during the development and implementation of NDT process Modeling of radiography Modeling conventional and phased array UT Modeling of eddy current 6-263

Module 6 - Inspection NDE Advancements RT Modeling Simulated X-Ray Radiograph of Weld Butt Joint with Weld Defects Setup Screen 6-264

Module 6 - Inspection NDE Advancements RT Modeling - 3D POD Maps 0.6-mm Flaw 0.4-mm Flaw Undetectable Questionable Detectability Images courtesy of NDTEducation 6-265

Module 6 - Inspection NDE Advancements UT Modeling PA Contact Probe Angle Steering and Focusing 6-266

Module 6 - Inspection NDE Advancements UT Modeling of Complex Part Misaligned specimen (2.5D-CAD specimen with revolution)

Customized PA Delay Laws Compensate for Component Geometry Effect 6-267

Module 6 - Inspection NDE Advancements ET Modeling - Multilayer Subsurface Sliding probe and inspection area with fasteners are modeled for the 4e-4 Imaginary Component, V first time in NDE industry Modeled signals compared well with actual signals 0

-4e-4

-8e-4 -4e-4 0 Real Component, V Fastener Hole without Notch Fastener Hole with Notch in 3-rd Layer Lift Off Hole without Notch Hole with Notch Lift Off 6-268

Module 6 - Inspection NDE Advancements ET Modeling - Inconel Tube Testing Tube with Defects Differential Coil External Groove Internal Cavity Internal Groove 6-269

Module 6 - Inspection NDE Advancements New Developments New developments broaden the applications, reliability, and accuracy of NDE techniques Computed tomography Phased array ultrasonics (PA UT)

Advanced array eddy current (AEC)

The NDE becomes more quantitative than qualitative process 6-270

Module 6 - Inspection NDE Advancements Computed Tomography (CT)

CT Scan of Turbine Blade Image courtesy of NDTEducation 6-271

Module 6 - Inspection NDE Advancements Ultrasonic Phased Arrays (PA) Techniques One Dimensional Linear Array Lack of Side Wall Fusion Depth Focusing A-scan Beam Angle Steering 6-272

Module 6 - Inspection NDE Advancements PA UT & TOFD for Cr-Mo Heavy-walled Reactors Attachment - PE PA - 3 MHz (Right Atk.) Nozzle - PE PA - 3 MHz (CW Atk.)

Flaws Flaw Flaw Flaw Flaw Avg. UT Measured Flaw Hgt. vs Fabrication Flaw Hgt. Back Surface Flaw Flaw SE-CW Wedge Wedge Noise Nozzle Noise Avg. Measured Flaw Hgt. (mm)

SE-CCW Flaws 30 SE - P DE-CW DE-CCW DE - P Nozzle TOFD - 2 MHz 55o R.L.

20 PA-CW 1 Flaw PA-CCW Tip PA - P DPA-CW 10 DPA-CCW DPA - P Lateral Average 2 Wave Back Wall 0 TOFD Clad Interface 0 5 10 15 20 25 30 35 Fabrication Flaw Height (mm) Flaw 1 2 Avg. Measured = Average of 4 Average = Average of the maximum flaw data points near the flaw center heights for all techniques for each flaw Tip Advanced UT modeling and simulation tools Optimized and implemented PA UT and TOFD for nozzles and attachments in 100-300 mm heavy-walled clad reactors 6-273

Module 6 - Inspection NDE Advancements PA UT for Austenitic and Dissimilar Welds Developed dual phased array technology Better inspections of large grain, highly anisotropic materials, dissimilar steel welds and nickel based alloys 6-274

Module 6 - Inspection NDE Advancements Eddy Current Multipurpose Array Systems Up to 64 coils and 256 channels for conventional, array EC, Portable eddy current array magnetic flux leakage (MFL) and system for up to 32 coils remote field eddy current (RFEC) Scanner for Curved and Flat Surfaces Array EC Probes 6-275

Module 6 - Inspection NDE Advancements Conventional versus Advanced Eddy Current Techniques Conventional Probe Advanced Imaging - Same Fast Advanced Processing - Array and Crack Indication Probe and 3 Crack Indications Probe and Crack Indication Crack in LF sample similar to crack in RH sample (sectioned)

Cracks Crack Indication Correlated to Depth Crack Fast and reliable detection and flaw Slow scanning Reliable detection sizing Unreliable detection flaw sizing and sizing 6-276

NDE Qualification Module 6C

Module 6 - Inspection Outline Definitions Inspection background NDT personnel certification NDT procedures, qualification process and standards Specimens for POD and sizing POD and modeling for validation Inspection reliability Qualification standards, summary and references 6-278

Module 6 - Inspection Definitions ASME BPVC,Section V, Article 14 Examination System Performance Demonstration Qualification Qualification requirements for ultrasonic examination systems in ASME BPVC,Section XI, Appendix VIII, Article VIII-3000 6-279

Module 6 - Inspection NDE Qualification Inspection Background Reason(s) for performing NDT In-process, final, and in-service inspection Type(s) of flaws of interest in the object Volumetric or planar Size and orientation rejectable flaw Code, standard, other requirement Anticipated location of the flaws of interest in the object Surface and subsurface Size and shape of the object/part Simple, complex, large, small, sheet, tube, sphere, etc.

Characteristics of the material to be evaluated Density, roughness, paint, coating, electrical and thermal conductivity, magnetic permeability, tight or open cracks 6-280

Module 6 - Inspection NDT Personnel Certification - ASNT SNT-TC-1A Recommended Practice No. SNT-TC-1A: Personnel Qualification and Certification in Nondestructive Testing.

Provides guidelines for employers to establish in-house certification programs.

Provides the general framework for a qualification and certification program.

Provides recommended educational, experience and training requirements for the different test methods.

6-281

Module 6 - Inspection Other ASNT Standards and Guidelines for Nondestructive Testing Personnel ANSI/ASNT CP-189-2006 ASNT Standard for Qualification and Certification of Nondestructive Testing Personnel.

ANSI/ASNT ILI-PQ-2005 In-line Inspection Personnel Qualification and Certification ANSI/ASNT CP-105-2006 ASNT Standard Training Outlines for Qualification of Nondestructive Testing Personnel 6-282

Module 6 - Inspection Other ASNT Standards and Guidelines for Nondestructive Testing Personnel ANSI/ASNT CP-106-2007 Nondestructive Testing - Qualification and Certification of Personnel ASNT CP-107-2007 ASNT Standard for Performance-Based Qualification and Certification of Nondestructive Testing Personnel 6-283

Module 6 - Inspection NDE Qualification NDT Procedures Most in accordance with ASME Section III, V and XI as applicable UT examination of vessel and piping welds - ASME Section XI, Appendix III, Article III-2300 Weld types Scanning surface and surface conditions Equipment list Examination technique Calibration techniques Calibration block design Data and method of recording, interpretation of indications (III-4510)

Techniques for data interpretation and plotting Personnel qualification requirements 6-284

Module 6 - Inspection NDE Qualification NDT Procedures Separate articles dedicated to Calibration (III-3000) and Examination (III-4000)

Important to identify correct standard/specification and technique Essential Parameters 6-285

Module 6 - Inspection NDE Qualification NDT Qualification Process Input inspection data What to inspect, flaw size location, orientation, detection and sizing capabilities to be demonstrated Technical justification (in some codes)

Review of NDE procedure, essential parameters, personnel qualification, previous experience, mathematical modeling, determine scope of qualification Specimen preparation (if needed)

Special requirements for flaw sizes, location, spatial and size distribution, number of units with and without flaw, specimen quality provisions 6-286

Module 6 - Inspection NDE Qualification NDT Qualification Process Trials with specimens Open and blind depending on requirements and inspection criticality Processing of data and making decision regarding adequacy of inspection equipment and procedure and/or personnel to perform to required level Inspection objectives were met or were not met Quality assurance procedures for qualification process control Issue of certificates, conditions for certification and recertification, specimen storage and access etc.

6-287

Module 6 - Inspection NDE Qualification How Many Specimens Are Needed?

ASME BPVC,Section XI, Appendix VIII Supplement 2&3 - Wrought austenitic and ferritic piping welds 3 personnel qualification sets for initial procedure qualification (detection) 1 personnel qualification set for qualifying change of essential parameter Supplement 4 - Clad/base metal interface of reactor vessel 3 personnel qualification sets for initial procedure qualification (detection) 1 personnel qualification set for qualifying change of essential parameter Supplement 10 - Dissimilar metal piping welds 3 personnel qualification sets for initial procedure qualification (detection) 1 personnel qualification set for qualifying change of essential parameter Special requirements for flaw location on ID, OD and mid wall 6-288

Module 6 - Inspection NDE Qualification How Many Specimens Are Needed?

Confidence Number of Number of Sectors ASME BPVC,Section V, Misses with Flaws Article 14 requires number of POD 90% POD 95%

90% 0 22 45 successfully detected flaws 1 38 77 based on binomial law 2 52 105 POD estimates are relevant 3 65 132 4 78 158 for ONE FLAW SIZE ONLY 5 91 184 Different number required 10 152 306 depending on the POD and 20 267 538 95% 0 29 59 confidence 1 46 93 See table 2

3 61 76 124 153 Number of flaws to be 4 89 181 detected increases rapidly 5 103 208 with increase of misses 10 167 336 20 286 577 6-289

Module 6 - Inspection NDE Qualification How Many Specimens Are Needed?

European Methodology for Qualification of Non-destructive Testing (EMQNDT), Issue 3 Not specific on number of flaws Depends on criticality MIL-HDBK-1823 (latest 2007 draft)

At least 60 (ideally 120) flaws are required to build a reliable POD(a) curve when the hit/miss approach is implemented At least 40 flaws are required to build a reliable POD(a) curve when â vs. a approach is implemented because additional information is available In addition, other conditions (linearity, error normality, adequate size selection, uncorrelated measurements and uniform variance) shall be verified to ensure that POD(a) estimate is valid 6-290

Module 6 - Inspection NDE Qualification Issue of Flaw Sizing Qualification ASME BPVC,Section XI, Appendix VIII Uses root mean square (RMS) sizing error to accept or reject a qualification test mi - measured flaw size ti - true flaw size n - number of flaws measured n

(m t )

i i 2

RMS = i =1 n

6-291

Module 6 - Inspection NDE Qualification POD for Validation Weld flaws exhibit high variability Numerous factors may cause POD to vary widely Any POD data is specific to the application and conditions during test POD validation Concept of POD introduced in 1973 by NASA on shuttle program Similar requirements initiated by USAF The concept later received widespread adoption for quantifying and assessing of NDE capabilities 6-292

Module 6 - Inspection NDE Qualification POD for Validation ASME BPVC, 2008a Section V, Article 14 Defines POD as proportion of flaws detected to all flaws examined.

Binomial law used for POD of similar flaws MIL-HDBK-1823 Defines POD as function of flaw size (length or height or other parameter) and uses non linear regression for POD estimate 6-293

Module 6 - Inspection NDE Qualification Typical POD Curve vs. Defect Size Defect size of 90% 0.011 is a90/95 it Mean POD has 90/95 POD Probability Of Detection, %

Lower 95% Bound 90% of defects 0.011 and larger 50%

a50 are detected with 95% confidence (in a90 95% of the cases) a90, a50 are also used for system assessment a90/95 = 0.011 Actual Defect Size, Inches 6-294

Module 6 - Inspection NDE Qualification Modeling for Verification and Validation ASME BPVC,Section XI, Nonmandatory Appendix M Models are to have limitations known, performance verified, and results accepted if difference with known solutions is less than +/-

10%

ASME BPVC,Section V, Article 14 Modeling mentioned as part of technical justification (TJ)

ENIQ, Recommended Practice 6, Report No. 15, EUR EN 19017 Use and validation of models as part of TJ discussed in more details MIL-HDBK-1823 (latest 2007 draft), Appendix H Model applications discussed related to Model Assisted determination of POD (MAPOD)

See previous section on modeling in RT, UT and ET 6-295

Module 6 - Inspection NDE Qualification Factors Affecting Inspection Reliability Individual inspectors/human factors - experience, education, age, physical condition, attitude, and concentration Equipment - accuracy, sensitivity, analysis capability, versatility, portability, availability Procedures - simple and complex, general and specific, easy or difficult to follow Environment - production or in-field, laboratory or workshop, day or night, slow or fast paced, indoor or outdoor, in air (e.g.,

airborne, space, etc.), land, sea or underwater, accessibility 6-296

Module 6 - Inspection NDE Qualification Inspection Reliability Improvement Establish and maintain personnel certification system Central or employer based Use of readily available off-the-shelf equipment with well established capabilities Verification of procedure performance at the environment where it is expected to be carried out Use of procedure performance indicators Computer modeling, probability-of-detection (POD) curves, experimental data, past experience, industry data and specifications, expert judgment, etc.

Conducting performance demonstration (PDI) or NDE qualification programs for selected techniques, equipment and personnel Trails with actual specimens Sometimes qualification is based solely on technical justification (past experience, modeling etc.) 6-297

Module 6 - Inspection NDE Qualification NDE Qualification Standards NRC Specifications and Procedures NRC Inspection Manual ASME BPVC,Section XI - Rules for In-service Inspection of Nuclear Power Plant Components Appendix VIII - Performance Demonstration for Ultrasonic Examination Systems ASME BPVC,Section V - Nondestructive Examination Article 14 - Examination System Qualification Others European Methodology for Qualification of Non-destructive Testing (EMQNDT), Issue 3, European Network for Inspection Qualification (ENIQ) Report No. 31, EUR EN 22906 MIL-HDBK-1823, Nondestructive Evaluation System Reliability Assessment, Department of Defense Handbook 6-298

Module 6 - Inspection NDE Qualification Summary of NDE Qualification Reference appropriate ASME document Verify input information Clarify NDT specifics Use techniques with established capabilities Perform NDT demonstration if needed 6-299

Module 6 - Inspection NDE Qualification References ASME Standards ASM Metals Handbook, Volume 17, Nondestructive Evaluation and Quality Control MIL-HDBK-1823, Nondestructive Evaluation System Reliability Assessment ASTM Standards, Section 3, Metals Test Methods and Analytical Procedures, Volume 03.03, Nondestructive Testing 6-300

ASME Section XI - Rules for Inservice Inspection of Nuclear Power Plant Components Module 6C Prabhat Krishnaswamy Dr. Gery M. Wilkowski Engineering Mechanics Corporation of Columbus 3518 Riverside Drive - Suite 202 Columbus, OH 43221

Module 6 - Inspection ASME Section XI ASME Section XI - Early History Early power plant designers used high standards so that passive components of reactors could operate for their life without attention.

In 1966, the AEC (NRC) recognized an inspection program will be necessary for pressure-containing components.

A committee was developed and accepted as a subgroup of the ASME Section III Boiler and Pressure Vessel Committee.

ASME Section XI code was published in 1970, originally containing 24 pages of text.

Today, contains over 500 pages and covers Class 1, 2 and 3 systems primarily for light-water reactors 6-302

Module 6 - Inspection ASME Section XI ASME Section XI - Rules for Inservice Inspection of Nuclear Power Plant Components Three divisions Light-water cooled reactors (483 pages)

Subsections for light-water cooled reactors IWA - General requirements IWB - Requirements for Class 1 IWC - Requirements for Class 2 IWD - Requirements for Class 3 IDE - Requirements for Class MC IWF - Requirements for Supports IWL - Requirements for Concrete Components Mandatory Appendices Non-Mandatory Appendices Gas-cooled reactors(2 pages)

Liquid metal cooled reactors (1 page) 6-303

Module 6 - Inspection ASME Section XI IWA - General Requirements Points user to other Subsections (i.e., IWB-, IWC-, etc.)

IWA-1000 - Scope and Responsibility IWA-2000 - Examination and Inspection Duties, qualification, access for inspectors (Including NRC inspectors)

Examination methods (visual-VT, surface-MP/EC, volumetric-UT/R, alternative-AE; more details later)

Qualifications of Nondestructive Examination Personnel - ASNT qualified Level 1 < Level 2 < Level 3 Inspection program - (details later)

Extent of examination (excludes welds for repairs in base metals)

Weld reference system (i.e., 0-degrees is top of pipe) 6-304

Module 6 - Inspection ASME Section XI IWA - General Requirements IWA-3000 - Standards for Examination Evaluation Significant digits for limiting values Flaw characterization (discussed later)

Linear flaws detected by surface or volumetric examination (more detail later)

IWA-4000 - Repair/Replacement Activities General Requirements Items for Repair/Replacement Activities Design Welding, Brazing, Metal Removal, Fabrication and Installation Examination and Testing Alternative Welding Methods, i.e., temper bead welding for repair of ferritic materials to avoid post-weld heat treatment Heat Exchanger Tubing - plugging, explosive welding, friction welds, etc.

6-305

Module 6 - Inspection ASME Section XI IWA - General Requirements IWA-5000 - System Pressure Tests General System Test Requirements Test Records IWA-6000 - Records and Reports Scope Requirements Retention IWA-9000 - Glossary 6-306

Module 6 - Inspection ASME Section XI IWB - Class 1 Components IWB-1000 - Scope and Responsibility IWB-2000 - Examination and Inspection Preservice Inspection Schedule Examination and Pressure Test Requirements 6-307

Module 6 - Inspection ASME Section XI IWB - Class 1 Components IWB-3000 - Acceptance Standards Evaluation of examination results Supplemental examinations Standards Acceptance Standards- Workmanship flaw tables Analytical Evaluation of Flaws 3610 - 4 and thicker ferritic steel components 3620 - less then 4 thick ferritic steel components 3630 - Steam generator tubing 3640 - flaws in austenitic and ferritic piping 3660 - RPV head penetration nozzle flaws 3700 - Analytical evaluation of operating plant events Non-Mandatory Appendix A, C, G, H, K, L, O, Q IWB-5000 - System Pressure Tests 6-308

Module 6 - Inspection ASME Section XI IWC & IWD - Class 2 & 3 Components IWC-XXXX for Class 2 piping (39 pages)

IWD-XXXX for Class 3 piping (10 pages)

Generally IWC and IWD have much less detail than IWB, and IWC and IWD will frequently refer user to IWB.

Exception might be some criteria specific to Class 2/3 piping, i.e.,

flow-accelerated corrosion (FAC) also called erosion-corrosion.

6-309

Module 6 - Inspection ASME Section XI Other Subsections IWE-XXXX for Requirements for Class MC and Metallic Liners of Class CC Components of Light-Water Cooled Plants (10 pages) i.e., drywell containment vessel for BWRs (Oyster Creek corrosion)

IWF-XXXX for Requirements for Class 1, 2, 3 and MC component supports of Light-Water Cooled Plants (6 pages)

IWL-XXXX for Requirements for Class CC Concrete Components of Light-Water Cooled Plants (14 pages)

Appendices Mandatory (I-X)

Nonmandatory (A-R) 6-310

Module 6 - Inspection ASME Section XI Inspections The Code allows option for inspection programs, but a 10-year interval was chosen based on historical failure rate data Risk-based inspection currently being used to determine inspection frequencies of different components Non-mandatory Appendix R 6-311

Module 6 - Inspection ASME Section XI Inspection Methods Originally concerned with fatigue cracking.

Note, the design sections of the ASME Code are made for preclusion of overload failures of unflawed components and fatigue failures, not any other degradation modes.

SCC is much more common in nuclear plants - Code does good job in designing to avoid fatigue failures UT was chosen over RT for superiority in locating and sizing fatigue cracks UT can be performed from one surface Appendices were developed for techniques for improving UT reliability Appendix I for Vessels in 1973 Appendix III for piping in 1975 Currently eight appendices for UT 6-312

Module 6 - Inspection ASME Section XI Inspection of Class 1 Systems Systems subject to examination include; Reactor coolant system (RCS)

Portions of the auxiliary systems connected to RCS Portions of the Emergency Core Coolant System (ECCS)

ISI requirements were developed during and after the design/order of most US power plants Prior to 1977 Only 5% of each circumferential and 10% of each longitudinal vessel weld was required Except vessel-to-flange and head-to-flange welds After 1977 100% of the length of 25% of piping circumferential welds, and all circumferential dissimilar welds are required to be inspected 6-313

Module 6 - Inspection ASME Section XI Flaw Characterization If a flaw is found, it must first be characterized The code gives guidance in the form of figures for determining flaw size, etc. for analyses The figures are for all flaw types Surface, subsurface, multiple, planar,non-planar, etc.

6-314

Module 6 - Inspection ASME Section XI Flaw Characterization Spacing criteria (S) being updated Flaw interaction difference for subcritical crack growth like SCC of fatigue cracks than for failure criteria 6-315

Module 6 - Inspection ASME Section XI Flaw Acceptance Standards After the flaw is characterized, its size is compared with the Acceptance Standards These Acceptance Standard flaw sizes are also known as Workmanship flaws 6-316

Module 6 - Inspection ASME Section XI Flaw Acceptance Flaws that are smaller than these flaw sizes are acceptable for continued service without any evaluation Tables being updated recently Flaws that are larger than the acceptable flaw size can either be repaired, or replaced, or found acceptable by analytical evaluation 6-317

Module 6 - Inspection ASME Section XI Analytical Evaluation of Flaws The Code separates the evaluation of flaws into five categories Ferritic components where t > 4 inches (102mm)

Ferritic components where t < 4 inches Steam generator tubing Ferritic and austenitic piping PWR head penetration nozzles 6-318

Module 6 - Inspection ASME Section XI Flaw Evaluation Flow Chart Initial flaw size, ai Fatigue Subcritical flaw Pipe Normal operating SCC analysis stresses Emergency and Faulted Inspection SF interval Reduce Inspection Final flaw Allowable Flaw interval size, af size No Acceptance criteria Yes Repair/replace Continued Operation 6-319

Module 6 - Inspection ASME Section XI Flaw Evaluation for Class 1 Piping The Code gives the user choices in evaluating flaws in piping If the flaws exceed the workmanship size flaws, they can be analyzed by; Following the procedures in Nonmandatory Appendix C Following the procedures in Nonmandatory Appendix H Performing an alternate procedure, i.e., finite element analyses and demonstrating that the allowable loads have the following safety factors Service level A - 2.7 Service level B - 2.4 Service level C - 1.8 Service level S - 1.4 6-320

Module 6 - Inspection ASME Section XI Appendix C - Alternative Pipe Flaw Evaluation Criteria An Appendix C analyses has the following steps; Determine flaw size Resolve size into circumferential and axial components Determine stresses normal to flaw for Service Level A-D Perform a flaw growth analysis to determine flaw size at end-of-evaluation time period Obtain material properties at operating conditions Determine failure mode Determine allowable flaw size or allowable stress (with appropriate safety factors)

Note the term Safety Factor is being changed to Structural Factor Apply acceptance criteria Recently updated for Dissimilar Metal Welds (In82/182 - SCC susceptible materials in PWRs.

6-321

Module 6 - Inspection ASME Section XI Section XI Code Cases and Relief Request The Boiler and Pressure Vessel Committee meets regularly to consider proposed additions and revisions to the Code and to formulate Cases to clarify the intent of existing requirements or provide, when the need is urgent, rules for materials or constructions not covered by existing Code rules

~200 code cases in existence (N-4 to N-759 as of 7/09) 1/2 of them are for Section XI - rest for all other divisions of the code More recent ones deal with evaluation of PWSCC cracking inspection, evaluations, and repairs, i.e.,

N-735 - Successive inspections of Class 1 and 2 pipe welds N-740 - Dissimilar weld metal overlay for repair of Class 1, 2, and 3 items 6-322

Module 6 - Inspection ASME Section XI Evolving Areas of Section XI Plastic pipe being approved for service water lines (Code Case N-755)

Next step is inspection and flaw evaluation - lack of fusion girth welds Buried service water line flaw acceptance criteria Developing new procedures in Section XI for corrosion in steel buried pipes Similar to natural gas/oil line issues, but level of tolerable leakage sensitive to contaminates in the line Gen IV reactors developing design criteria in Section III NH Flaw acceptance criteria for creep/fatigue design may be in Section XI 6-323

Module 6 - Inspection ASME Section XI Evolving Areas of Section XI Code is not based on guidance for avoidance of SCC (most common type of degradation mechanism in existing plant high energy systems) - needs some significant improvements!

SCC requires combination of material, water environment, high stresses Usual cure is to change to a new material, try adjusting water chemistry, stress mitigation, repairs (overlays) or replacements For new plant construction, need better guidance on how to fabricate welds with reduced or no tensile residual stresses on wetted surface of pressure boundary 6-324