api 570 chapter 7-nde-rev-005

Chapter Seven

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NDE (Non Destructive Evaluation)

Do Not Duplicate

NDE

These course notes have been prepared by TWI, strictly for the use of attendees to this TWI API-570 Examination Preparation Course. This manual is to be used as an aid to assist those persons wishing to take

the API-570 Piping Inspector Certification Examination. This manual is not all-inclusive and may not be used in place of any recognized Code or Standard. This manual may not be reproduced by any means

without the express written consent of TWI.

THE WELDING INSTITUTE

REV.005 NDE (570 ED) 2 Copyright © TWI Ltd 2008

ASME SECTION V, ARTICLE 1 T-110 Scope

• General requirements for NDE when referenced by other Codes • Appendix A contains a list of common flaws and methods of detection • General NDE terms are defined in the Mandatory Appendix 1

T – 120 General • Subsection A describes methods of NDE to be used. • Subsection B lists NDE Standards. • Reference to a paragraph in Subsection A or referencing Code includes all applicable

rules in the paragraph • Standards in Subsection B are mandatory only to the extent specified when referenced • When this Article is referenced NDE Personnel shall be qualified per the employers

written practice which must comply with: – the User of this Article is responsible for personnel certification.

- the User’s quality program shall specify the method. - certifications to previous versions of standards are good until recertification.

• When no personnel qualification standard is referenced qualification may be by demonstration in routine operations of competency in accordance with Manufacturer’s procedures

• Limited certification of NDE personnel who perform only one operation of an NDE method or perform within scope may be based on less hours than specified in SNT-TC-1A, CP-189 or ACCP - Such conditions shall be described in the Written Practice and noted on any

certifications

T-130 Equipment The Code User is responsible for equipment compliance T-150 Procedure Special conditions such as part geometry or materials may require special procedures. If required they shall:

- Be equivalent or superior to the methods and techniques described in Section V. - Produce interpretable examination results - Be capable of detecting discontinuities - Be submitted to the Inspector for approval

The manufacturer, fabricator or installer is responsible for establishing:

- examination procedures - personnel certification procedures



When required by referencing code sections all NDE performed shall be done in accordance with a written procedure:

- demonstrated to the satisfaction of the Inspector - in compliance with the applicable Article of Section V - Made available to the Inspector on request - Available to the NDE personnel performing the examinations for reference and use

T-160 Calibration • The manufacturer, installer or fabricator shall assure that all required calibrations are

performed. • The Code User shall specify what calibrations are needed when using special procedures; if

required T- 170 Examinations and Inspections The inspector is responsible for:

- verifying that all examinations meet all of requirements Section V and referencing Code

- witness any examinations to the extent stated in the referencing Code - Inspector means the Authorized Inspector as defined in the referencing Code

Inspection: - Refers to the functions of the Authorized Inspector

Examination: - Refers to the functions of the NDE PERSONNEL - There are some minor conflicts in these definitions in the ASTM documents.

However; the ASTM documents are excluded by the Body of Knowledge

T- 180 Evaluation Acceptance standards are as stated in the Referencing Code T- 190 Records/Documentation Records shall be in compliance with:

• The referencing Code and • Section V

The Code User shall be responsible for all records and documentation.



MAGNETIC TESTING (MT)

ASME Section V, Article 7 T-710 Scope - When specified by referencing Code Section, the MT techniques of this Article shall be used - This Article generally in conformance with ASTM SE-709, Standard Recommended Practice

for Magnetic Particle Examination. (ASTM Standard are excluded in the 653 Body of Knowledge.)

- SE-709 provides additional details to be considered in the procedures used - Article 7 shall be used together with Article 1, General Requirements - Definition of term used found in Mandatory Appendix II which will send you to SE-1316. T-720 General The magnetic particle method is applied to detect cracks and other discontinuities on or near the surfaces of ferromagnetic materials.

- Sensitivity greatest for surfaces discontinuities - Sensitivity decreases rapidly with increasing depth of discontinuity.

Principle

- Magnetizing an area to be examined - Applying ferromagnetic particles to the surface - Particles form patterns on surface / discontinuities cause distortions in nominal

magnetic field. - Patterns are usually characteristics of type of discontinuity detected - Maximum sensitivity is to linear discontinuities oriented perpendicular to the lines of

flux. - Examine each area twice for optimum effectiveness in detecting all types off

discontinuities. - Lines of flux during one examination to be perpendicular to lines of flux during the

other.



T-721 Written Procedure Requirements MT Shall be performed to a written procedure the procedure shall contain the requirements listed in Table 721 as a minimum the procedure shall set a single value or range of values for each requirement. T-730 Equipment - Suitable and appropriate means used to produce the necessary magnetic flux - Use techniques listed in T-752 and described in T-770 T-731 Examination Medium

Ferromagnetic particles shall meet the following requirements: - Particles:

• Adequate contrast with surface • Specific requirements given in SE-709

- Temperature Limits given in manufacturer’s literature, or as qualified in the procedure in accordance with Article 1, T-150.

T-741 Surface Preparation & Enhancement • Results usually satisfactory when surfaces are in the as-welded, as-rolled, as-cast, or as-

forged condition - Grinding or machining may be necessary where surface irregularities could mask

indications due to discontinuities • Prior to examination: examine surface and all adjacent areas within 1 inch shall be dry, free

of dirt, grease, lint, scale, welding flux, weld spatter, paint, oil, and other extraneous matter that could interfere with the examination

• Typical cleaning agents: detergents, organic solvents, descaling operations, and paint removers, degreasing, sand or grit blasting, or ultrasonic cleaning methods also may used

• If coatings left on part, it must be demonstrated that indications can be detected through the existing maximum coating thickness. When an AC yoke is used the demonstration must be in accordance with Mandatory Appendix I or of this Article. - When temporary coatings are used to enhance particle contrast it must be demonstrated

that indications can be detected through the enhancement coating



T-750 Techniques One or more of five magnetization techniques shall be used:

- prod technique - longitudinal magnetization technique - circular magnetization technique - yoke technique - multidirectional magnetization technique

T-752 Prod Technique T-752.1 Magnetizing Procedure

- magnetization is accomplished by portable prod type contact pressed against the surface to be examined

- to avoid arcing, a remote control switch shall be provided to permit the current to be applied after the prods have been properly positioned.

T-752.2 Magnetizing Current

- direct or rectified magnetizing current shall be used - current shall be 100 (minimum) amp/in. (3.9 amp/mm) to 125 (maximum) amp/in. (4.9

amp/mm) of prod spacing for sections 3/4 in. (19 mm) thick or greater. - for sections less than 3/4 in. (19 mm) thick, the current shall be 90 amp/in. (3.5 amp/mm)

to 110 amp/in. (4.3 amp/mm) of prod spacing. T-752.3 Prod Spacing

- prod spacing shall not exceed 8 in. (203 mm) - shorter spacing may be used to accommodate the geometric limitations or to increase the

sensitivity - prod spacings of less than 3 in. (76 mm) are usually not practical due to banding of the

particles around the prods. - the prod tips shall be kept clean and dressed - if the open circuit voltage of the magnetizing current source is greater than 25 V, lead,

steel, or aluminium tipped prods are recommended to avoid copper deposits on the part being examined

T-755 Yoke Technique T-755.1 Application

- only be applied to detect discontinuities that are open to the surface of the part



T-755.2 Magnetizing Procedure

- alternating or direct current electromagnetic yokes - or permanent magnet yokes - NOTE: For materials 1/4 in. (6 mm) or less in thickness, alternating current yokes are

superior to direct or permanent magnet yokes of equal lifting power for the detection of surface discontinuities.

T-760 Calibration of Equipment T-761 Frequency of Calibration (for equipment with ammeters) Frequency:(for equipment with ammeters)

- Calibrate each piece of equipment at least once per year - Calibrate prior to first use after major electrical repair, periodic overhaul, or damage

Procedure: - accuracy of meter verified annually by equipment traceable to a national standard - Take readings at 3 different current out put levels encompassing the usable range

Tolerance: - Unit’s meter reading shall not deviate more than ± 10% full scale, relative to the actual

current value shown by the test meter.

T-762 Lifting Power of Yokes • Electromagnetic – Check magnetizing force within the last year • Permanent magnet – must be checked daily, prior to use • Whenever a yoke has been damaged or repaired • Alternating current yoke shall have a lifting power of at least 10 LB at the maximum pole

spacing to be used • Direct current yoke or permanent magnet yoke shall have a lifting power of at least 40 LB at

the maximum pole spacing to be used • Test weights to be weighed with a scale from a reputable manufacturer and stencilled with

the applicable nominal weight prior to its first use • verify weight only if damaged in a manner that could have caused potential weight loss



T-764 Magnetic Field Adequacy and Direction T-764.1 Magnetic Field Adequacy

- the magnetic field shall have sufficient strength to produce satisfactory indications - shall not be so strong that it causes masking of relevant indications by non-relevant

accumulations of magnetic particles Factors that influence the required field strength include the:

- part size - part shape - material permeability of the part - technique of magnetization - coatings - method of particle application - type and location of discontinuities to be detected

When it is necessary to verify the adequacy of magnetic field strength, it shall be verified by using one or more of the following three methods:

- 764.1.1 Pie-Shaped Magnetic Particle Field Indicator - 764.1.2 Artificial Flaw Shims - 764.1.3 Half-Effect Tangential Field Probe

T-770 Examination T-771 Preliminary Examination

- check area for openings that may not hold particles due to width T-772 Direction of Magnetization

- Perform 2 separate examinations on each area - During 2nd examination, lines of magnetic flux shall be approximately perpendicular to

those used during 1st examination - A different technique may be used for 2nd examination -For example: Yoke 1st and Prod 2nd

T-773 Method of Examination

- particles may be either wet or dry - may be either fluorescent or non-fluorescent - examination(s) shall be done by the continuous method



Dry Particles - magnetizing current shall remain on while the examination medium is being applied - and while any excess of the examination medium is removed

Wet Particles

- magnetizing current shall be turned on after the particles have been applied - flow of particles shall stop with the application of current - wet particles applied from aerosol spray cans may be applied before and/or after current is

applied - wet particles may be applied during the application of current if not applied directly to the

examination area and are allowed to flow over the examination area or area applied directly to the examination area with low velocities insufficient to remove accumulated particles

T-774 Examination Coverage Conduct with sufficient overlap to assure 100% coverage at required sensitivity

T-776 Excess Particle Removal

- excess dry particles in examinations shall be removed with a stream of low pressure dry air - examination current or power shall be maintained while removing the excess particles

T-777 Interpretation • shall identify if an indication as false, non-relevant, or relevant • false and non-relevant indications shall be proven as false or non-relevant • identify the locations of indications • the character of the indication T-777.1 Visible (Colour Contrast) Magnetic Particle • discontinuities are indicated by accumulations particles which contrast with the examination

surface • colour of the particles shall be sufficiently different than the colour of the examination

surface • a minimum light intensity of 100 fc (1000 Lx) is required on the surface to be examined • light source, technique used, and light level verification is required to be demonstrated one

time documented and maintained on life



T-777.2 Fluorescent Magnetic Particles same as 777.1 (above) with the exception that the examination is performed using an ultraviolet light, called black light. The examination shall be performed as follows:

- shall be performed in a darkened area. - the examiner shall be in the darkened area for at least 5 min prior to performing the

examination - if the examiner wears glasses or lenses, they shall not be photosensitive - the black light shall be allowed to warm up for a minimum of 5 min prior to use or

measurement of the intensity of the ultraviolet light emitted. - reflectors and filters should be checked and cleaned daily in use - Cracked or broken filters shall be replaced immediately - the black light intensity shall be measured with a black light meter - a minimum of 1000 µW/cm2 on the surface to be examined is required - the black light intensity shall be verified at least once every 8 hr, whenever the work station

is changed, or whenever the bulb is changed T-778 Demagnetization

- do if residual magnetism in the part could interfere with subsequent processing.

T-780 Evaluation

- all indications shall be evaluated in terms of the acceptance standards of the referencing Code Section.

- discontinuities on or near the surface are indicated by retention of the examination medium - localized surface irregularities due to machining marks or other surface conditions may

produce false indications - broad areas of particle accumulation, which might mask indications from discontinuities,

are prohibited, and such areas shall be cleaned and re-examined

T-791 Multidirectional Magnetization A technique sketch shall be prepared for each different geometry examined, showing:

- the part geometry - cable arrangement and connections - magnetizing current for each circuit - and the areas of examination where adequate field strength are obtained

Parts with repetitive geometries, but different dimensions, may be examined using a single sketch provided that the magnetic field strength is adequate when demonstrated in accordance with T-755.2.



T-792 Recording of Indications T-792.1 Non-rejectable Indications

- Non-rejectable indications shall be recorded as specified by the referencing Code Section.

T-792 Rejectable Indications Rejectable indications shall be recorded. As a minimum, the:

- type of indications (linear or rounded) - location and extent (length or diameter or aligned) shall be recorded.

T-793 Examination Records For each examination, the following information shall be recorded:

(a) procedure identification and revision (b) magnetic particle equipment and type of current (c) magnetic particle (visible or fluorescent, wet or dry) (d) examination personnel identity and if required by referencing Code Section,

qualification level (e) map or record of indications per T-792 (f) material and thickness (g) lighting equipment (h) date and time examinations were performed

T-794 Performance Demonstration Performance demonstration, when required by the referencing Code Section, shall be documented ASME Section VIII, Appendix 6, Paragraph 6-3 Definition of indication. Must be larger than 1/16”. ASME Section VIII, Appendix 6, Paragraph 6-4 Acceptance Standards - All surfaces to be examined shall be free of:

a) Relevant linear indications b) Relevant rounded indications – greater than 3/16” c) Four or more relevant rounded indications in line separated by 1/16” or less, edge to

edge.



PENETRANT TESTING (PT)

ASME Section V, Article 6 T-610 Scope Liquid penetrant examination techniques described in this Article shall be used:

- when specified by the reference Code Section - techniques described in this Article shall be used - this Article is in conformance with SE-165, Standard Test Method for Liquid Penetrant

Examination - this document provides details to be considered in the procedures used

When this Article is specified by a referencing Code Section:

- the liquid penetrant method described in this Article shall be used together with Article 1, General Requirements.

- Definitions of terms used in this Article appear in Mandatory Appendix 1 of this Article and Article 1, Appendix 1

T-620 General The liquid penetrant examination method is an effective means for detecting: • discontinuities which are open to the surface of nonporous metals and other materials

Typical discontinuities detectable by this method are: • cracks • seams • laps • cold shuts • laminations • porosity

In principle: • a liquid penetrant is applied to the surface to be examined • allowed to enter (penetrate) open discontinuities • excess penetrant is removed • the part is dried • a developer functions both as:

- a blotter to absorb penetrant that has been trapped in discontinuities - and as a contrasting background to enhance the visibility of penetrant indications



The dyes in penetrants are either:

- color contrast (visible under white light) - or fluorescent (visible under ultraviolet light)

T-621 Written Procedure Requirements T-621.1 Requirements Liquid penetrant examination shall be performed in accordance with a written procedure which shall as a minimum, contain the requirements listed in Table T-621. The written procedure shall establish:

- a single value - or range of values - for each requirement

T-621.2 Procedure Qualification When procedure qualification is specified: A change of requirements in Table T-621 identified as an essential variable

- from the special value - or range of value - shall require requalification of the written procedure.

A change of a requirement identified as a nonessential variable - from the specified value - or range of values - does not require requalification of the written procedure.

All changes of essential or nonessential variables from the value or range of values specified by the written procedure shall require:

- revision - or an addendum to, the written procedure.



T-630 Equipment The term penetrant materials, as used in this Article, is intended to include:

- all penetrants - emulsifiers - solvents - or cleaning agents - developers

used in the examination process. The descriptions of the material types are provided in SE 165 of Article 24 T-640 Miscellaneous Requirements T-641 Control of Contaminants The user of this Article shall obtain certification of contaminant content for all liquid penetrant materials used on:

- nickel base alloys - austenitic stainless steels - and titanium

These certifications shall include: - the penetrant manufacturer’s batch numbers - the test results obtained in accordance with Mandatory Appendix II of this Article - these records shall be maintained as required by the referencing Code Section

T-642 Surface Preparation In general, satisfactory results may be obtained when the surface of the part is in the:

- as-welded - as-rolled - as-cast, or - as-forged condition

Surface preparation by: - grinding - machining - or other methods

*may be necessary where surface irregularities could mask indications.*



Prior to each liquid penetrant examination the surface to be examined and all adjacent areas within at least 1 in. (25mm) shall be dry and free of all:

- dirt - grease - lint - scale - welding flux - weld spatter - paint, oil, - and other matter that could obscure surface openings or interfere with the examination.

Typical cleaning agents which may be used are:

- detergents, organic solvents, de-scaling solutions, and paint removers, - degreasing and ultrasonic cleaning methods may also be used.

Cleaning solvents shall meet the requirements of T-641. The cleaning method employed is an important part of the examination process. T-643 Drying After Preparation After cleaning, drying of the surfaces to be examined shall be accomplished by:

- normal evaporation - or with forced hot or cold air.

A minimum period of time shall be established to ensure that the cleaning solution has evaporated prior to application of the penetrant. T-650 Technique T-651 Techniques Either a colour contrast (visible) penetrant or a fluorescent penetrant shall be used with one of the following three penetrant processes:

• water washable • post-emulsifying • solvent removable

The visible and fluorescent penetrants used in combination with these three penetrant processes result in six liquid penetrant techniques.



T-652 Techniques for Standard Temperatures As a standard technique, the temperature of the penetrant and the surface of the part to be processed shall:

- not be below 50 F (10 C) - nor above 125 F (52 C) - throughout the examination period.

Local heating or cooling is permitted provided the part temperature remains in the range of 50 F to 125 F (10 C to 52 C) during the examination. Where it is not practical to comply with these temperature limitations, other temperatures and times may be used, provided the procedures are qualified as specified in T-653. T-653 Techniques for Nonstandard Temperatures When it is not practical to conduct a liquid penetrant examination within:

- 50 F to 1250 F (10 C to 52 C) - the procedure at the proposed lower or higher temperature range - requires qualification in accordance with Mandatory Appendix III of this Article.

T-654 Technique Restrictions

- fluorescent penetrant examination shall not follow a color contrast penetrant examination - Intermixing of penetrant materials from different families or different manufacturers is

not permitted - retest with water washable penetrants may cause loss of marginal indications

T-660 Calibration Visible and fluorescent (black) light meters, shall be calibrated:

- at least once a year - whenever the meter has been repaired - if meters have not been in use for one year or more, calibration shall be done before being

used T-670 Examination T-671 Penetrant Application The penetrant may be applied by any suitable means, such as:

- dipping - brushing - spraying



If the penetrant is applied by spraying using compressed-air-type apparatus: - filters shall be placed on the upstream side near the air inlet to preclude contamination.

T-672 Penetration (Dwell) Time Penetration (dwell) time is critical. The minimum penetration time shall be:

- as required in Table T-672 - or as qualified by demonstration for specific applications

T-673 Excess Penetrant Removal After the specified penetration (dwell) time has elapsed:

- any penetrant remaining on the surface shall be removed - take care to minimize removal of penetrant from discontinuities

T-673.1 Water-Washable Penetrants Excess water-washable penetrant shall be removed:

- with a water spray - water pressure shall not exceed 50 psi (345 kPa), - water temperature shall not exceed 110ºF (43ºC).

T-673.2 Postemulsification Penetrants

• Lipophilic Emulsification. • Hydrophilic Emulsification

NOTE: Additional information may be obtained from SE-165 T-673.3 Solvent Removable Penetrants. Excess solvent removable penetrants shall be removed by

- wiping with a cloth or absorbent paper, - repeating the operation until most traces of penetrant have been removed - remaining traces shall be removed by lightly wiping with cloth paper moistened with

solvent - care shall be taken to avoid the use of excess solvent

NOTE: Flushing is Prohibited - flushing the surface with solvent, following the application of the penetrant and prior to developing is prohibited



T-674 Drying After Excess Penetrant Removal For the water washable or post-emulsifying technique, the surfaces may be dried by:

- blotting with clean materials - using circulating air - temperature of the surface may not be raised above 125 F (52 C)

For the solvent removable technique, the surfaces may be dried by: - normal evaporation - blotting - wiping - forced air

T-675 Developing The developer shall be applied as soon as possible after penetrant removal:

- the time interval shall not exceed that established in the procedure - insufficient coating thickness may not draw the penetrant out of discontinuities - excessive coating thickness may mask indications - with colour contrast penetrants, only a wet developer shall be used - with fluorescent penetrants, a wet or dry developer may be used

T-675.1 Dry Developer Application. Dry developer shall be applied only to a dry surface by:

- soft brush - hand power bulb - powder gun - or other means - provided the powder is dusted evenly over the entire surface being examined

T-675.2 Wet Developer Application. Wet developer must be thoroughly agitated to ensure adequate dispersion of suspended particles (a) Aqueous Developer Application. Aqueous developer may be applied to either a wet or dry surface it shall be applied by:

- dipping - brushing - spraying - or other means provided a thin coating is obtained over the entire surface being

examined - Drying time may be decreased by using warm air - Temperature of the part may not be raised above 125’F (52 C). - Blotting is not permitted



(b) Nonaqueous Developer Application. Nonaqueous developer shall be applied only to a dry surface. It shall be applied by:

- spraying - under such conditions, developer may be applied by brushing - drying shall be by normal evaporation.

T-675.3

- developing time for final interpretation begins immediately after application of a dry developer

- or as soon as a wet developer coating is dry - minimum developing time shall be as required by Table T-672

T-675 Interpretation T-676.1 Final Interpretation.

- shall be made within 10 to 60 min after the requirements of T-675.3 are satisfied - if bleed-out does not alter the examination results, longer periods are permitted - if the surface to be examined is large enough to preclude complete examination within

the prescribed or established time, the examination shall be performed in increments T-676.2 Characterizing Indication(s)

- type of discontinuities are difficult to evaluate if the penetrant diffuses excessively into the developer

- if this condition occurs, close observation of the formation of indications(s) during application of the developer may assist in characterizing and determining the indication(s).

T-676.3 Colour Contrast Penetrants

- developer forms a reasonably uniform white coating - discontinuities are indicated by bleed-out of the penetrant (normally a deep red color) - indications with a light pink colour may indicate excessive cleaning - inadequate cleaning may leave an excessive background making interpretation difficult - minimum light intensity of 100 fc (1000 Lx) is required on the surface



T- 676.4 Fluorescent Penetrants. The examination shall be performed as follows:

- shall be performed in a darkened area. - examiner shall be in the darkened area for at least 5 min prior to performing the

examination to enable his eyes to adapt to dark viewing - if the examiner wears glasses or lenses, they shall not be photosensitive. - light shall be allowed to warm up for a minimum of 5 min prior to use - or measurements of the intensity of the ultraviolet light emitted - reflectors and filters should be checked and cleaned daily when in use - cracked or broken filters shall be replaced immediately

Black light intensity shall be measured with a black light meter

- a minimum of 1000μ W/cm2 on the surface of the part being examined shall be required - black light intensity shall be re-verified: - at least once every 8 hr - whenever the work station is changed - or whenever the bulb is changed.

T-677 Post-examination Cleaning post-examination cleaning should be conducted as soon as practical after evaluation and documentation using a process that does not adversely affect the part T-680 Evaluation

- all indications shall be evaluated in terms of the acceptance standards of the referencing Code Section

- localized surface irregularities due to machining marks or other conditions may procedure false indications

- broad areas of fluorescence or pigmentation which could mask indications of discontinuities are unacceptable, and such areas shall be cleaned and reexamined.

T-691 Recording of Indications T-691.1 Non-rejectable Indications. Non-rejectable indications shall be recorded as specified by the referencing Code Section T-691.2 Rejectable Indications rejectable indications shall be recorded. The following shall be recorded as a minimum:

- type of indications (linear or rounded) - location - extent (length or diameter or aligned)



T-692 Examination Records For each examination, the following information shall be recorded:

(a) procedure identification and revision; (b) liquid penetrant type (visible or fluorescent); (c) type (number or letter designation of each penetrant, penetrant remover, emulsifier, and

developer used; (d) examination personnel identity and if required by referencing Code Section, qualification

level; (e) map or record of indications per T-691; (f) material and thickness; (g) lighting equipment; and (h) date and time examinations were performed.

T-693 Performance Demonstration Performance demonstration, when required by the referencing Code Section, shall be documented. Appendix II – Control of Contaminants for Liquid Penetrant Examination U-610 Scope this Appendix contains requirements for the control of contaminant content for all liquid penetrant materials used on nickel base alloys, austenitic stainless steels, and titanium. U-640 Requirements U-641 Nickel Based Alloys

- when examining nickel based alloys, all materials shall be analysed individually for sulphur content

- the sulphur content shall not exceed 1% of the residue by weight. U-642 Austenitic Stainless Steel and Titanium when examining austenitic stainless steel or titanium, all materials shall be analysed individually for chloride



ASME Section VIII Division 1 Appendix 8 Paragraph 8-3 Evaluation of Indications An indication is the evidence of a mechanical imperfection. Only indications with major dimensions greater than 1/16” shall be considered relevant.

a. A linear indications is one having a length greater than three (3) times the width.

b. A rounded indication is one of circular or elliptical shape with the length equal to or less then three times the width.

c. Any questionable or doubtful indications shall be re-examined to determine whether or not they are relevant.

Appendix 8 Paragraph 8-4 Acceptance Standards All surfaces shall be free of:

a. Relevant linear indications b. Relevant rounded indications greater than 3-16” c. Four or more relevant rounded indications separated by 1/16”

ULTRASONIC TESTING (UT)

ASME Section V, Article 23, SE-797 1. Scope This practice provides guidelines for measuring the thickness of materials:

• using the contact pulse-echo method • at temperatures not to exceed 200ºF (93ºC) • applicable to any material in which ultrasonic waves will propagate at a constant

velocity throughout the part • and from which back reflections can be obtained and resolved • The values stated in either inch-pound or S1 units are to be regarded as the standard • The values given in parentheses are for information only • This standard does not purport to address all of the safety concerns

4. Summary of Practice Thickness M, when measured by the pulse-echo ultrasonic method, is a product of the velocity of sound in the material and one half the transit time(round trip) through the material.



Vt

T = ------ 2

where: T = thickness, V = velocity t= transit time.

NOTE: The pulse-echo ultrasonic instrument measures the transit time of the ultrasonic pulse through the part

7. Procedure-Calibration and Adjustment of Apparatus

Case 1 – Direct Contract, Single-Element Search Unit: Case II – Delay Line Single-Element Search Unit: Case III – Dual Search Units: Case IV – Thick Sections:

8. Technical Hazards

1. Dual search units:

a. may be used effectively with rough surface conditions

b.only the first returned echo, such as from the bottom of a pit, is used in the measurement

c. generally, a localized scanning search is made to detect the minimum remaining wall.

2. Material Properties:

a. the instrument should be calibrated on a material having the same acoustic velocity and attenuation as the material to be measured

b.where possible, calibration should be confirmed by direct dimensional measurement of the material to be examined.

3. Scanning:

a. the maximum speed of scanning should be stated in the procedure b.the following may require slower scanning:

- material conditions - type of equipment - operator capabilities



4. Geometry: a. Highest accuracy can be obtained from materials with parallel or concentric

surfaces b.It is possible to obtain measurements from materials with nonparallel surfaces.

However: the accuracy of the reading may be limited as follows: - the reading obtained is generally that of the thinnest portion of the section being

interrogated by the sound beam at a given instant - relatively small diameter curves often require special techniques and equipment - when small diameters are to be measured, special procedures including additional

specimens may be required to ensure accuracy of setup and readout.

5. High-Temperature materials: a. high-temperature materials, up to about 540oC (1000oF) can be measured with

specially designed instruments with high temperature compensation, search unit assemblies, and couplants

b.normalization of apparent thickness reading for elevated temperatures is required c. a rule of thumb often used is as follows:

- the apparent thickness reading obtained from steel walls having elevated temperatures is high (too thick) by a factor of about 1% per 55oC (100oF)

- if the instrument was calibrated on a piece of similar material at 20oC (68oF). and if the reading was obtained with a surface temperature of 460oC (860oF), the apparent reading should be reduced by 8%

- this correction is an average one for many types of steel - other corrections would have to be determined empirically for other materials.

6. Instrument:

a. time base linearity is required so that a change in the thickness of material will produce a corresponding change of indicated thickness

b.if a CRT is used as a readout, its horizontal linearity can be checked by using Practice E 317.

7. Back Reflection Wave-train:

a. direct-thickness readout instruments read the thickness at the first half cycle of the wave-train that exceeds a set amplitude a fixed time.

b.If the amplitude of the back reflection from the measured material is different from the amplitude of the back reflection from the calibration blocks, the thickness readout may read to a different half cycle in the wave-train, thereby producing an error

c. this may be reduced by: - using, calibration blocks having attenuation characteristics equal to those in the

measured material. - Or adjusting back reflection amplitude to be equal for both the calibrating blocks

and measured material.



d.using an instrument with automatic gain control to produce a constant amplitude back reflection.

8. Readouts:

a. CRT displays are recommended where reflecting surfaces are rough, pitted, or corroded

b.direct-thickness readout, without CRT, presents hazards of mis-adjustment and misreading under certain test conditions such as: - especially thin sections - rough corroded surfaces - and rapidly changing thickness ranges

9. Calibration Standards:

a. Greater accuracy can be obtained when the equipment is calibrated on areas of known thickness of the material to be measured

10. Variations in echo signal strength

a. may produce an error equivalent to one or more half-cycles of the RF frequency, dependent on instrumentation characteristics.

9. Procedure Requirements In developing the detailed procedure the following items should be considered:

• Instrument manufacturer’s operating instructions • Scope of materials/objects to be measured • Applicability, accuracy requirements • Definitions • Requirements • Personnel • Equipment • Procedure qualification • Procedure • Measurement conditions • Surface preparation and couplant • Calibration and allowable tolerances • Scanning parameters • Report • Procedure used • Standardization (calibration) record • Measurement record



10. Report Record the following information at the time of the measurements and include it in the report:

• Examination procedure. • Type of instrument. • Standardization (calibration) blocks, size and material type • Size, frequency, and type of search unit • Scanning method • Results • Maximum and minimum thickness measurements • Location of measurements • Personnel data, certification level

SUPPLEMENTAL UT TECHNIQUES This section of the course provides a brief introduction into some of the other UT techniques that are mentioned in for example 571 and 577 recommended practices.

SHEAR WAVE ULTRASONIC TESTING (SWUT)

SWUT is used for the inspection of welds as the angle of the beam is selected to intersect defects perpendicular to the beam path.



TIME OF FLIGHT DIFFRACTION (TOFD) ToFD is an automated ultrasonic inspection technique that produces a high-resolution image of an item ToFD Inspection Methodology

• The item to be tested is straddled by a scanner assembly that contains ultrasonic transducers and an encoder to measure the distance that the transducers travel.

• One transducer floods the test area with pulses of ultrasonic energy. The other transducer is used to detect diffraction from geometric features and any flaws that may occur.

• Signal processing is used to convert this information into an image, which can be interpreted by skilled operators to define item condition.

• The signals, processed image, calibration parameters and other relevant information are stored electronically and can be recalled whenever required

GUIDED WAVE ULTRASONIC TESTING (GWUT)

GWUT or more commonly called LRUT (Long Range Ultrasonic Testing) concept was developed at Imperial college with TWI (The Welding Institute) with the major aim of developing a method of inspection for insulated pipe-work for detecting external Corrosion Under Insulation (CUI). Detailed experimental studies and site trials, backed up by numerical modeling using finite elements, showed that guided waves propagating in the pipe wall can be used to detect both internal and external corrosion in pipe-work systems. The Teletest® LRUT system for monitoring pipes and pipelines in service was introduced commercially by Plant Integrity Ltd (Pi) in early 1998. It was found that this new technology has far wider applications than just CUI and has since been found a useful tool for screening remote and inaccessible piping such as risers, road crossings, furnaces and boilers.



Equipment LRUT equipment consists of a bracelet transducer array, a purpose built 24 channel low frequency flaw detector and a ‘ruggerdised’ laptop computer (Figure 1). The bracelet transducer array which consists of an inflatable collar (Figure 2) and separate multi-mode modules (Figure 3) fitted with transducers (Figure 5) is placed around the pipe and inflated. The bracelet transducer array is modular in design allowing easy interchanges of separate transducers, modules and or leads if the need arises.

Figure 1. Bracelet Transducer Array Figure 2. Inflatable Collar

Figure 1. Teletest System Figure 3. Multimode Module

Figure 4. Mini-Test Figure 5. Individual Transducers The computer and specifically produced software package, which controls the test, communicates via an umbilical cable which can extend up to 100m with the low frequency flaw detector which energises the transducers and receives the returning signal responses.



LRUT Inspection Methodology LRUT ultrasonic methods use so called guided ultrasonic waves and these wave have the property that their velocity is independent of frequency over a wide range of frequencies (Figure 6). Guided waves, similar in form to Lamb waves, have the characteristic that any change in frequency may change their velocity. Normally this form of wave propagation would spread in every direction similar to the waves formed by a stone tossed in a pond which expand radially outward and dissipate. Given that on pipe the entire volume of the cross sectional area is filled with the wave motion because of the encircling bracelet of transducers the guided waves can propagate up to hundred metres in plain pipe. In contrast with conventional ultrasonic testing, where generally only a single mode such as either compression or shear exists, a large number of guided wave modes are possible during a single test with LRUT. In order for the responses from discontinuities in pipes to be interpretable it is necessary to use selected wave modes that allow the signals to be simplified.

Fig 6. Dispersion curves for guided waves in pipes, showing the fast moving non-dispersive L(0,2) mode

To generate the appropriate wave modes in common pipe thicknesses, frequencies in the range 20 - 120 kHz are utilised, compared with around 5MHz for conventional thickness testing. These waves can travel many metres with minimal attenuation and therefore offer the potential of testing large distances from a single point using a pulse-echo transducer collar wrapped around the pipe. Where changes in the thickness of the pipe, either on the inside or the outside, cause reflections they are detected by the transducer (Figure 9). Hence metal loss defects from corrosion/erosion inside the pipe or corrosion on the outside of the pipe can be detected.



Figure 9. Principle of operation of long range ultrasonic testing of pipes

Anomalies are located by distance from the transducer and approximate circumferential location. By separating the transducer modules into quadrant sets allows for the approximate circumferential location to be determined. These quadrant sets of transducers independently receive returning signals, allowing for any flexural changes in the returning signal to be detected, thereby providing quadrant location. Data is presented in a ‘A scan’ fashion with black lines indicating symmetrical results, redlines are horizontal flexural and blue is used to indicate vertical flexural responses (Figure 10). This pipe length is free from any corrosion and the trace shows a clean baseline with sharp peaks from the butt welds in the line. The Teletest® system applies a phased input to the different parts of the transducer which makes it possible to send the ultrasound in one direction only along the pipe. By sending the ultrasound in one direction only avoids any confusion in interpretation. By switching the input the test may be performed in the opposite direction.



Figure 10. Inspection data results.

Numerous factors affect the sound wave propagation and subsequent system performance. Surface condition Geometry Contents

Bare metal

Smooth well bonded paint

Fusion bonded epoxy

Light pitting

Heavy pitting

Bitumastic coated

Concrete coated

Straight lengths

Attachments/brackets

Branches

Multiple bends

Gas

Liquid

High viscosity

Difficult

Ease of Test



RADIOGRAPHIC TESTING (RT)

ASME Section V, Article 2 – Radiographic Examination T-210 – Scope When this Article is specified by the referencing Code Section, the radiographic method described in this Article shall be used together with Article 1, General Requirements.

T- 220 General Requirements T- 221 Procedure Requirements T- 221.2 – Radiographic examination shall be performed to a written procedure. Requirements and Compliance for a Written Radiographic Procedure Minimum Contents of a Written Procedure:

- material & thickness range - isotope used or maximum X-ray voltage - minimum source-to-object distance - Maximum distance from source side of object to the film - Maximum source size - film brand and designation - screens used

Demonstration of the density and IQI image requirements of the written procedure on production or technique radiographs shall be considered satisfactory evidence of compliance with that procedure



T- 222 Surface Preparation T-222.1 – Materials Surfaces shall satisfy the requirements of the applicable materials specification. Additional conditioning may be required (grinding, etc.), if necessary, by any suitable process to a degree that surface irregularities cannot mask or be confused with surface discontinuities. T-222.2 – Welds Weld ripples or weld surface irregularities on both the inside and outside shall be removed by any suitable process to such a degree that the resulting radiographic image due to any irregularities cannot mask or be confused with the image of any discontinuity. The finished surface of all butt-welded joints may be flush with the base in the referenced Code Section. (API 650 and/or API 653 in the case of Atmospheric Aboveground Storage Tanks) T-223 Backscatter Radiation A lead symbol “B” with minimum dimensions of ½” in height and 1/16” in thickness, shall be attached to the back of each film holder during each exposure to determine if backscatter radiation is exposing the film. T-224 System of Identification Permanent identification system shall be establish to trace radiograph to the contract, component, weld or weld seam, or part numbers, as appropriate. In addition:

- Manufacturer’s symbol or name and the date of the radiograph shall be plainly and permanently included on the radiograph.

- I.D. system does not require that the information appear as radiographic image - the information shall not obscure the area of interest.

T-225 Monitoring Density Limitations of Radiographs Either a densitometer or step wedge comparison film shall be used for judging film density. T-226 Extent of Examination The extent of examination shall be as specified by the referencing code. T-230 Equipment and Materials



T-231 Film T-231.1 Radiographs shall be made using industrial radiographic film. T-231.2 Processing – The following shall be used as a guide for processing film:

- SE -999 - SE-94, Part III

T-232 Intensifying Screens May be used except when restricted by the referencing Code Section. T-233 Image Quality Indicator (IQI) Design - IQI’s shall be either hole type or wire type - Manufactured and identified in accordance with:

- SE-1025 (for hole type) - SE-747 (for wire type)

- ASME standard IQI’s shall consist of those in: Table T-223.1 for hole type (See table in Section V) Table T-233.2 for wire type (See table in Section V) T-270 Examination T-271 Radiographic Technique T-271.1 Single-Wall Technique

- Use whenever practical - Radiation passes through only one wall of the weld (material) - Adequate number of exposures shall be made to determine required coverage

T-271.2 Double-Wall Technique

- Use when a single-wall technique is not practical - Radiation passes through two walls of the weld (material) for a double wall exposure. For

single wall views, only one wall is viewed. For double wall views (3.5 in. nominal O.D. or less) both walls may be viewed.

- Adequate number of exposures shall be made to demonstrate required coverage

A) Single-Wall Viewing via Double-Wall Technique - for materials and for welds in components - weld (material) on the film side is viewed for acceptance on the radiograph. - When complete coverage is required for circumferential welds, a minimum of 3

exposures taken 120 degrees to each other shall be made.



b) Double-Wall Viewing via Double-Wall Technique For materials and for welds in components 3.5-inches or less in nominal OD the radiation

passes through two walls/weld in both walls is viewed for acceptance only a source side IQI shall be used

- If the geometric un-sharpness requirement cannot be met use single-wall viewing T-274 Geometric Un-sharpness Geometric un-sharpness of the radiograph shall be determined in accordance with:

Ug = Fd/D

Where: Ug = geometric unsharpness. F = source size; the maximum projected

dimension of the radiating source (or effective focal spot) in the plane perpendicular to the distance D from the weld or object being radiographed, inches.

D = distance from source of radiation to weld or object being radiographed, inches.

d = distance from source side of welded or object being radiographed, inches.

T-275 Location Markers (See Fig. T-275) - to appear as radiographic images on the film - shall be placed on the part, not on the exposure holder/cassette. - their locations are to be permanently marked on surface of part being radiographed - or on a map in a manner permitting the area of interest to be accurately traceable - Locations shall be available for the required retention period of the radiograph - Evidence provided on the radiograph that the required coverage has been obtained T-280 Evaluation T-281 Quality of Radiographs All radiographs must be free from mechanical, chemical, or other blemishes to the extent that they do not mask and are not confused with the image of any discontinuity in the area of interest of the object being radiographed. Such blemishes include, but are not limited to:

- fogging - processing defects such as streaks, watermarks, or chemical stains - scratches, finger marks, crimps, dirtiness, static marks, smudges, or tears - false indications due to defective screens



T-282 Radiographic Density The transmitted film density through the radiographic image of the body of the appropriate hole IQI or adjacent to the designated wire of a wire IQI and the area of interest shall be:

- 1.8 minimum for single film viewing for radiographs made with an X-ray source - 2.0 minimum for radiographs made with a gamma ray source - For composite viewing of multiple film exposures, each film of the composite set shall

have a minimum density of 1.3 - The maximum density shall be 4.0 for either single or composite viewing - A tolerance of 0.05 in density is allowed for variations between densitometer readings

T-283 IQI Sensitivity Radiography shall be performed with a technique of sufficient sensitivity to display

- the hole IQI image and the 2T - or the designated wire of a wire IQI - the radiographs shall display the ID numbers and letters. - If the required hole IQI image and specified hole, or designated wire, do not show

on any film in multiple film technique, but do show in composite film viewing, interpretation shall be permitted only by composite film viewing

- If a thinner or thicker IQI is substituted for those shown in Table T-276 the requirements of Table T-283 must be met (i.e., if Table T-276 calls for a 35 IQI and the required hole is 2T, then a 50 IQI showing a 1T hole or a 25 IQI showing a 4T hole may be used as alternatives).

T-284 Excessive Backscatter

- If a light image of the “B” appears on a darker background of the radiograph, protection from backscatter is insufficient and the radiograph shall be considered unacceptable

- A dark image of the “B” on a lighter background is not cause for rejection. T-285 Geometric Unsharpness Limitations Shall not exceed:

Material Ug Thickness in inches Maximum in inches Under 2” 0.020” 2” through 3” 0.030” Over 3” through 4” 0.040” Greater than 4” 0.070”

NOTE: Material thickness is the thickness on which the IQI is based.



T-290 DOCUMENTATION T-291 Radiographic Technique Documentation Details Details of the radiographic examination technique used shall accompany each group of radiographs. As a minimum the information shall include:

- identification, e.g., job or heat number - data specified in T-275.3 when applicable (dimensioned ID marker map) - number of exposures - isotope or maximum X-ray voltage used - effective focal spot sizes - material type and thickness range - minimum source-to-object distance - maximum distance from source side of object to the film - film brand and designation - number of films per cassette - single-or double-wall exposure - single-or double-wall viewing

SUPPLEMENTAL RT TECHNIQUES This section of the course provides a brief introduction into some of the other RT techniques that are mentioned in for example 571 and 577 recommended practices.

NEUTRON BACKSCATTER Operation Theory The device contains a small quantity of sealed radioactive material that emits fast neutrons but also gamma radiation. This is provided by an Americium 241 Beryllium neutron emitting compound of low activity; approximately 1.85GBq (50 milli Curies) with a 458 year half-life. These “fast” neutrons travel outward in all directions from the base of the hand held instrument penetrating the material under test. Some of these neutrons are reflected back towards the detectors mounted in the base of the Hydrotector head producing a pulse. These backscattered neutrons are called “thermal” neutrons. The number of pulses is proportional to the amount of Hydrogen atoms contained in the test material and therefore by inference, the likely concentration of water moisture.



SUPPLEMENTAL NDT TECHNIQUES This section of the course provides a brief introduction into some of the other NDT techniques that are mentioned in for example 571 and 577 recommended practices.

ALTERNATING CURRENT FIELD MEASUREMENT (ACFM) The ACFM technique is an electromagnetic non-contacting technique that is able to detect and size surface breaking defects in a range of different materials and through coatings of varying thickness.

• Requires minimal surface preparation. • Can be used at elevated temperatures up to 9000F (4820C). • Uses a probe similar to an eddy current probe and introduces an alternating

current in a thin skin near to the surface of any conductor.

When a uniform current is introduced into the area that is defect free, the current flows undisturbed. If the areas have a crack, the current flows around the ends and the faces of the crack. A magnetic field is present above the surface associated with this uniform alternating current and will be disturbed if a surface-breaking crack is present.



Two components of the magnetic field are measured:

Bx along the length of the defect, which responds to changes in surface current density and gives an indication of depth when the reduction is the greatest; and Bz which gives a negative and positive response at either end of the defect.

During the application of the ACFM technique actual values of the magnetic field are being measured in real time. These are used with mathematical model look-up tables to eliminate the need for calibration of the ACFM instrument using a calibration piece with artificial defects such as slots.



NDE – PRACTICE QUESTIONS 1. The __________________ is responsible for examination equipment calibration records.

a) Code User b) NDE technician calibrates his own equipment and c) company that manufactures the NDE equipment d) Authorized Inspector

2. At least __________________ copy/copies of an NDE procedure must be available to the Manufacturers

Nondestructive Examination Personnel at the work site. a) two b) one c) none d) there is no requirement

3. The difference between as inspection and an examination per Section V of the ASME Code is:

a) Inspections are NDE functions performed by contractors b) “examinations” are QC functions performed by the manufacturer’s employees c) “inspections” are performed by the Authorized Inspector d) 2 & 3 above

4. How must all Nondestructive Examination Personnel be qualified when Article 1 is referenced?

a) per the manufacturer’s PQR’s b) per the requirements of their employers written practice c) The AI will specify the requirements for each job d) they are always qualified per ASNT SNT-TC-1A

5. Which of the following is not part of the minimum content of a written radiographic procedure?

a) type of screens used if any b) type of emulsion used c) film brand & designation d) maximum X-ray voltage or isotope used

6. How can compliance with a written radiographic procedure be demonstrated?

a) by showing the film to the Authorised Inspector b) by confirming the accuracy of the radiographs with a welder or welding foreman c) by verifying the proper density and demonstrating the IQI image requirements d) by demonstrating the required sensitivity by showing the “3T” hole in a hole type IQI

7. What finished surface is required of butt welds?

a) all surface cracks must run vertically in the center b) all surface cracks must run horizontally in the center c) they must not have any irregularities or contours that will mask defects or interfere with

interpretation d) they must not have any undercut or pinholes that will mask defects or interfere with interpretation

8. One reason for a system of radiographic film identification is:

a) to identify the film manufacturer b) so the location of detects will be traceable to the weldment c) to keep track of how much film is used for billing purposes d) so the welders will know where to have the film placed by the radiographer



9. Intensifying screens may be used ________________ a) only when radiographing at night b) only for Polaroid SE-1968 instant radiographs c) when performing radiography in accordance with ASME Section V, Article 2 d) for color radiographs only

10. IQIs may be what types?

a) wire b) hole c) crack d) 1 & 2 above

11. Viewing facilities for radiographs shall ____________________

a) be small, warm and comfortable enough for afternoon naps b) have adjustable lighting with lots of ferns and plans c) be bright and airy with lots of ferns and plants d) have subdued background lighting that will not cause glare on the film

12. The direction of the central beam of radiation should be _________________ the area of interest whenever

practical. a) as close as possible to b) centered on c) no more than 18” from d) at least 36” from

13. Where are hole type IQIs placed when radiographing welds?

a) always in the center of the weldment b) adjacent to or on the weld but not in the area of interest c) on the film side d) none of the above

14. Where are location markers placed if they are to appear as a radiographic image?

a) on the part to be radiographed b) on the film in the dark room c) on the IQI top side over the “2T” hole d) 1 & 3 above

15. The IQIs is normally placed on which side of a part?

a) the IQI is optional so it doesn’t matter b) the film side; the same side of the part to be inspected as the comparator c) the source side except when inaccessibility prevents hand placement on that side d) the film side; the same side of the part to be inspected as the film

16. What designation is used to indicate the IQIs is on the film side?

a) it is only noted on the radiographic report – there is no other designation used b) the welder noted it on the weld map c) the IQI may not be placed on the film side d) a lead letter “F” placed next to or on the IQI



17. How many IQIs should appear on each radiograph? a) there must always be one on every radiograph and it must appear as a radiographic image b) there must always be one on every radiograph but it need not appear as a radiographic image c) there must always be two on every radiograph and it must appear as a radiographic image d) it depends on the configuration used to set up the shot (panoramic multifilm, single shots, etc)

18. Shims may be placed under IQIs to simulate weld reinforcement to assure the density in the area of interest is

no more than __________________ lighter than the density through the IQI. a) 10% b) 25% c) 15% d) 5%

19. Which of the following blemishes is permitted on film as long as they do not interfere with interpretation and

do not mask or become confused with discontinuities in the area of interest? a) fogging & false indications from defective screens b) scratches, crimps, static marks & dirtiness c) processing defects such as streaks & water marks d) all of the above

20. The minimum density requirements for single film viewing are:

a) 1.8 for film made gamma ray and 2.0 for film made with an X-ray machine b) 4.0 for film made gamma ray and 4.0 for film made with an X-ray machine c) 2.0 for film made gamma ray and 1.8 for film made with an X-ray machine d) no more than 25% lighter in any area than the density in the darkest area

21. When using only one IQI per film density measurements may vary through the area of interest by no more

than ________________ or additional IQIs will be required. a) minus 15% or plus 30% b) plus 15% or minus 30% c) plus 1.5 X ratio of average densities d) no more than 15% from the density of the step wedge

22. Which of the below is an essential indication of sensitivity for image quality of a radiograph?

a) display of the welders stampings b) clearly visible location markers c) display of the designated hole or essential wire of the IQI used d) proper density variations within 50% of the IQI thickness

23. Excessive backscatter in indicated by:

a) a lead letter “F” being visible on the radiograph b) a dark image of the letter “B” on a lighter background c) any image of the lead letter “B” in the background of the film d) a light image of the lead letter “B” on a dark background

24. A tank is built with plate under 2 inches thick. The geometric un-sharpness of the radiographs shall not

exceed: a) 0.010” b) 0.020” c) 0.030” d) 0.040”



25. The following information may not be included in the documentation accompanying the radiographs: a) minimum source to object distance and film brand & designation b) number of exposures & film identification c) Isotope & effective focal spot sizes d) development time & exact shim material specifications

26. When the radiographs are presented to the Authorized Inspector ______________

a) he will interpret them and indicate the disposition of each film on the report b) he will view them only after a good lunch paid for by the NDE technician. c) the manufacturer will have interpreted all the film and will have indicated the disposition of each

on the report and will have also included all the other information required to on the report. d) the radiographs will be marked with a permanent marker or by other means to indicate which

technician processed them 27. Which of the following is not a type of discontinuity liquid penetrant examination is effective in detecting.

a) cold shuts & laminations b) subsurface cracks c) pinholes d) seams

28. Which of the following is an essential variable for a Liquid Penetrant procedure?

a) post examination cleaning details b) materials, shapes & sizes to be examined c) decrease in penetrant dwell time d) processing details for removal of excess penetrant

29. Revisions to PT procedures may be required if there is

a) a change in surface preparation b) a change or substitution in type or family of penetrant materials c) a change in the method of applying developer d) All of the above

30. Which of the following penetrant techniques may not be used?

a) solvent removable b) hard drying fluorescent c) water washable d) post emulsifying

31. What materials require the use of tested and certified liquid penetrants as to the contaminants in the

penetrant? a) carbon steels with > 3% chrome b) aluminum c) nickel base alloys & titanium d) copper

32. What condition must the surface to be examined be in prior to conducting the examination?

a) dry & free of all remedial demagnetization materials & effects b) dry & free of any oil, grease, lint, scale or other extraneous matter for 1” on all sides of the area to

be examined c) free of all subsurface defects previously detected by other methods d) dry & free of extraneous matter for 2” on all sides of the area to be examined



33. How shall PT indications be evaluated per ASME Article 6? a) per universal acceptance standards in ASNT SNT-TC-1A b) in terms of the acceptance standards of the referencing code section c) per the specific requirements in appendix N.5.3 of API-789 d) per the Owner/User procedures for NDE

34. The minimum period of drying time after initial cleaning is _________________.

a) at least 5 minutes to assure that all the cleaning solution has evaporated prior to applying the penetrant

b) a minimum time established to assure that all the cleaning solution has evaporated prior to applying the penetrant

c) at least 15 minutes to assure that all the cleaning solution has evaporated prior to applying the penetrant

d) at least 10 minutes to assure that all the cleaning solution has evaporated prior to applying the penetrant

35. Which of the following is not a suitable means of removing penetrant.

a) flushing water washable penetrant with water spray of less than 50 PSI & 110 F b) steaming water washable penetrant at 300 PSI to remove it c) wiping solvent removable penetrant with a lint free cloth d) rinsing post emulsifying penetrant at a temperature & pressure as recommended by the

manufacturer 36. Without special qualification penetrant testing can be performed between _______________ degrees.

1. 50 degrees F to 135 Degrees F 2. 50 degrees F to 125 degrees F 3. 72 degrees F to 130 Degrees F 4. 50 degrees F to 130 Degrees F

37. When PT examination is to be performed above or below _________________ the procedure is qualified for

the temperature range intended using a ____________. a) 50 degrees F to 125 degrees F --- Image Quality Indicator b) 50 degrees F to 125 degrees F --- field indicator c) 50 degrees F to 125 degrees F --- comparator d) 50 degrees F to 125 degrees F --- and DAC curve

38. Fluorescent penetrant examination shall not follow _________________.

a) UT thickness measurement b) radiography because the residual radiation will cause false indications c) Eddy current examination d) color contrast PT examination

39. The emulsification time for lipophilic emulsification of a post emulsifying penetrant is:

a) 90 seconds b) 6 minutes c) 10 minutes d) as determined experimentally

40. When removing water washable penetrant the spray of water may not exceed?

a) 100 degrees F & 50 psi b) 90 degrees F & 60 psi c) 110 degrees F & 50 psi d) 110 degrees F & 55 psi



41. Water washable and post emulsifying penetrants may be dried using circulated air as long as the surface of the part does not exceed:

a) 100 degrees F b) 110 degrees F c) 212 degrees F d) 125 degrees F

42. Five typical of discontinuities detectable by the magnetic particle method are:

a) seams, low carbon content, cold shuts, laminations, and bad developing b) cracks, caustic embrittlement, seams, and silicon isotope matrix syndrome c) excessive weld seam reinforcement, cracks, cold shuts, seams, and low viscosity d) cracks, laps, seams, cold shuts and laminations

43. What is the magnetic particle examination medium?

a) the surface of ferromagnetic work pieces b) dry, wet or fluorescent ferromagnetic particles c) any type of small metal particles d) high iron content enamel or latex coatings

44. If coatings are left in place during MT examination ______________

a) the particles used must be the same color as the coating b) coatings are not allowed to be left in place – all coatings must be removed c) the procedure must be demonstrated as capable of detecting indications through the maximum

thickness of the coating applied d) all indications must be verified with penetrant examination in addition to the magnetic particle

examination 45. What type of discontinuity is the magnetic particle method most sensitive to?

a) subsurface discontinuities b) slag inclusions not open to the surface c) linear discontinuities perpendicular to the lines of flux d) high nickel alloy weld defects

46. When performing fluorescent MT examiners shall allow _________________ for their eyes to adjust to the

darkened conditions. a) 5 minutes b) 90 seconds c) 3 minutes d) 10 minutes

47. The intensity of the black light used shall be a minimum of:

a) 800 μ W / cm2 12” from the surface of the part being examined b) 600 μ W / cm2 on the surface of the part being examined c) 1800 μ W / cm2 18” from the surface of the part being examined d) 1000 μ W /cm2 on the surface of the part being examined

48. Normally dry particles may not be used on surfaces above:

a) 800º F and 135 º F b) ambient temperatures c) 600 º F and 135 º F d) the manufacture’s recommendations



49. Magnetic field strength may be verified by using ______________ a) an amp meter to determine if the field is within ± 10% of full scale b) the proper IQI manufactured using all magnetically identical materials c) an ohm meter to determine if the field is within ± 5% of full scale d) pie shaped magnetic particle field indicator or artificial flaw shims

50. All examinations will be conducted with sufficient overlap to assure a minimum of __________________

coverage? a) 99% b) 100% c) 80% d) 90

51. When using the prod technique the maximum prod spacing allowed is _____________

a) 1 foot b) 3 inches c) 1/2 foot d) 8 inches

52. Magnetic particle equipment with ammeters must be calibrated _________________

a) always prior to each use b) after every 10 examination sessions c) before and after examination d) prior to first use if it the equipment has not been used for a year or more

53. AC yokes must be able to lift ______________ pounds at a maximum spacing of ______________.

a) 40 pounds at the maximum spacing to be used during examinations b) 10 pounds at the maximum spacing of 18 inches or 1 1/2 feet c) 40 pounds at the maximum spacing of 1.5 times the length of the yoke legs d) 10 pounds at the maximum spacing to be used during examinations

54. MT equipment with ammeters must be calibrated to a standard ________________

a) supplied by the MT equipment manufacturer b) supplied by the ISO MT standards committee c) traceable to a National Standard d) welded by a qualified welder or welding operator qualified in accordance with ASME Section V

55. What is the maximum temperature of materials covered under SE 797?

a) 350º F b) 400º F c) 150º F d) 200º F

56. SE-797 provides guide lines for the ________________ method for measuring thickness.

a) “Z” scan b) contact pulse echo c) submerged radiant echo d) real time 1/2 echo



57. A pulse echo instrument measures the _____________ of the ultrasonic pulse though the part. a) speed b) wave c) velocity d) transit time

58. Reference blocks used to calibrate equipment should have an ultrasonic velocity:

a) of V= .4562 X 3 b) of no less than 210,000 inches c) the same as the piece to be tested d) based on sheer wave impact

59. Which is not a type of thickness measurement instrument?

a) Flaw detectors with CRT readout b) Flaw detectors with CRT floor scan pressure readout c) Flaw detectors with CRT and direct thickness readout d) Direct thickness readout.

60. For measuring thin section which type of search unit is generally used?

a) Highly damped, high frequency b) Highly attenuated, low frequency c) Highly damped, low frequency d) 5 MHz single element

61. When using a direct contact, single element search unit the display start is:

a) based on the average value of the display b) synchronized to the initial pulse c) equal to e = m2 d) always at the top

62. When performing a complete calibration of an instrument using a delay line single element search unit

calibration blocks should be: a) At least two – one near the maximum thickness of the range to be measured and one near the mid

range b) At least two – a 1 inch block and a 6 inch block of the same velocity c) At least three blocks with a minimum difference in thickness between each of at least 1 inch d) At least two with a thickness near the maximum of the range to be measured and the other block

near the minimum thickness 63. When calibrating a UT instrument using Case II, what minimum number of test blocks should be used when

the instrument must be completely calibrated with the delay line search unit? a) 3 b) 4 c) 2 d) 1

64. When using dual search units there is an inherent error due to the:

a) distance between the units b) velocity rate averages c) Vee path that the sound beam travels d) geometry of the special calibration blocks required



65. When measuring materials at high temperatures the readings are high by a factor of: a) 1% per 50º F b) 1% per 10º F c) 5% per 50º F d) 1% per 100º F

66. When developing a detailed UT thickness measurement procedure which of the following does not need to be

considered? a) Equipment b) lighting conditions c) surface preparation and couplant d) allowable tolerances and calibration

67. Which of the following would not be included in a UT report:

a) examination procedure b) Calibration blocks, size and material type c) density readings d) Size, frequency, and type of search unit



NDE ANSWER KEY

1 A, T-130 2 B, T-150 3 D, T-170 4 B, T-120, (e) 5 B, T-221.1 5 B, T-221.1 6 C, T-221.2 7 C, T-222.2 8 B, T-224 9 C, T-232 10 D, T-233 11 D, T-234 12 B, T-273 13 B, T-277 14 A, T-275 15 C, T-277.1, (a) 16 D, T-277.1, (b) 17 D, T-277.3 18 C, T-277.3 19 D, T-281 20 C, T-282 21 A, T-282 22 C, T-283 23 D, T-284 24 B, T-285 25 D, T-291 26 C, T-292 27 B, T-620 28 C, T-621 29 D, T-621 30 B, T-651 31 C, T-641 32 B, T-642 33 B, T-680 34 B, T-643 35 B, T-673.1 36 B, T652

37 C, T-653 38 D, T-654 39 D, T-673.2 40 C, T-673.1 41 D, T-674 42 D, T-720 43 B, T-731 44 C, T-741 45 C, T-720 46 A, T-777 47 D, T-777 48 D, T-731 49 D, T-764 50 B, T-774 51 D, T-752 52 D, T-761 53 D, T-762 54 C, T-761 55 D, T-797 – 1.1 56 B, T-797 – 1.1 57 D, T-797 – 4.2 58 C, T-797 – 4.4 59 B, T-797 – 6.1 60 A, T-797 – 6.2 61 B, T-797 -7.1.1 62 D, T-797 – 7.2.2.1 63 C, T-797 – 7.2.2.1 64 C, T-797 – 7.3.1 65 D, T-797 – 8.5 66 B, T-797 - 10 67 C, T-797 - 10

api 570 chapter 7-nde-rev-005

Engineering