inspecciÓn mediante phased array/tofd segÚn la …

8ª Jornada Andina de Ductos ACIEM, 24 y 25 de 2013. Club el Nogal, Bogotá – Colombia

Elaborado por: Ing. Carlos Enrique Suárez Navas ASNT NDT Level III

INSPECCIÓN MEDIANTE PHASED ARRAY/TOFD SEGÚN LA ULTIMA VERSIÓN DE ASME SEC V (2013)

INTRODUCCIÓN

Uno de los principales objetivos de los ensayos no destructivos (NDT) es la detección de discontinuidades en soldaduras. Tradicionalmente se ha empleado la radiografía. Sin embargo, dadas las bondades del ensayo de Ultrasonido en cuanto a seguridad, reducción de contaminación al medio ambiente y reducción de tiempos muertos durante la realización del ensayo, cada vez se utiliza con mayor frecuencia técnicas como Phased array, TOFD, AUT, o combinación de éstas. El código ASME SEC V incluye diferentes posibilidades de realizar el ensayo de ultrasonido las cuales trataremos durante la presentación.

OBJETIVOS

Concientizar a los usuarios y compañías que realizan Ensayos No Destructivos c o n t e c n o l o g í a s a v a n z a d a s d e ul t rasonido, sobre las di ferentes alternativas que nos brinda el ASME SEC V, art 4. Versión 2013, que alternativa utilizar y que requisitos se deben cumplir cuando se quiere cambiar radiografía por ultrasonido según ASME SEC VIII Div. 1

TOFD: ASME SEC V. Apéndice Mandatorio III

TOFD: ASME SEC V. Apéndice Mandatorio III

El ensayo automatizado de TOFD (Time of flight diffraction) es una poderosa herramienta para la inspección de soldaduras, muy utilizada mundialmente en el sector petroquímico minero y nuclear. La técnica permite realizar un control de calidad muy rápido y eficiente a soldaduras de gran espesor, o con configuraciones de bisel complejas, donde la técnica P-E o PAUT puede tener problemas. La técnica de TOFD detecta las discontinuidades sin importar su orientación, sin embargo posee 2 zonas muertas, por lo que el ensayo debe combinarse con técnicas ultrasónicas como UT convencional, UT PE mecanizado o Phased array.

DESCRIPCIÓN DE LA TECNICA TOFD

El ensayo de TOFD se basa en un sistema de adquisición de datos a computador, el cual registra las variaciones en el tiempo de vuelo de ondas de difracción. Actualmente todos los sistemas de inspección automatizada de soldaduras incluyen el TOFD, ya que permiten detectar d i s c o n t i n u i d a d e s c o n orientación vertical, como en el caso de la IF (falta de fusión) en juntas de HDPE.

Main Formulas and Ultrasonic Reference Data 71

Figure 2-40 Principle of TOFD and the phase sign of four major signals. The defect is assumed to be symmetrically located between the probes. The phase of each RF signal is

marked with “+” and “–”.

Back-wall reflection

Lateral wave

Tip diffraction

++

__

Lateralwave

Uppertip

Lowertip

Back wall

DESCRIPCION DE LA TÉCNICA TOFD

Scanning Patterns and Views 175

Figure 4-14 Example of a color-encoded rectified A-scan signal used to create a color-coded B-scan.

Ultrasonic data with an RF display is usually encoded as gray-scale pixels,

with black and white limits from −100% to 100% (see Figure 4-15) to preserve

the phase information. Gray-scale amplitude encoding is used in TOFD

setups and data analysis, as shown in Figure 4-15.

Figure 4-15 Encoding of RF signal amplitude in gray-scale levels.

100

0

100%

0%

Ultrasonic path / TOFIndex

axis

Ampli

tude

A-SCAN

B-SCAN TOFD

Superficie externa de soldadura

Superficie interna de soldadura

Defecto

REGISTRO TIPICO DE INSPECCION TOFD

Registro TOFD con discontinuidades

Registro TOFD sin discontinuidades

FLUJOGRAMA PARA INSPECCIÓN POR TOFD

Referencing Code Section

MANDATORY APPENDIX III

TIME OF FLIGHT DIFFRACTION

(TOFD) TECHNIQUE

NONMANDATORY APPENDIX N

TIME OF FLIGHT DIFFRACTION

(TOFD) INTERPRETATION

Acceptance Standards

SHALL BE

TECNICA PHASED ARRAY

•  Phased array manual •  Phased array con encoder

Principios Físicos

PHASED ARRAY: VENTAJAS

◆  Alta velocidad de barrido electronico sin movimiento del palpador

◆  Mejora las posibilidades de inspección, controlando las características del haz mediante software

◆  Inspección mendiante múltiples angulos con un simple control electrónico del palpador

◆  Variedad de configuraciones: P/E, T/R, TOFD, Tandem

◆  Gran flexibilidad para la inspección de geometrías coplejas

  Enforque optimizado   Barrido de ángulos, localizado

PHASED ARRAY: PRINCIPIOS FÍSICOS

PHASED ARRAY: BARRIDO EN CONFIGURACIÓN LINEAL (E-SCAN)

HAZ NORMAL HAZ ANGULAR

PHASED ARRAY: BARRIDO EN CONFIGURACIÓN SECTORIAL (S-SCAN)

HAZ -30° a 30° HAZ 35° a 70°

MANDATORY APPENDIX IV PHASED ARRAY MANUAL RASTER

EXAMINATION TECHNIQUES USING LINEAR ARRAYS

2013 ASME Boiler and Pressure Vessel CodeA N I N T E R N A T I O N A L C O D E

ASME SEC V

PHASED ARRAY MANUAL

Se realiza la técnica phased array en configuración Lineal o Sectorial, de conformidad con ASTM E2700

PHASED ARRAY MANUAL

MANDATORY APPENDIX IVPHASED ARRAY MANUAL RASTER EXAMINATION TECHNIQUES

USING LINEAR ARRAYS

IV-410 SCOPEThis Mandatory Appendix describes the requirements

to be used for phased array, manual raster scanning, ultra-sonic techniques using linear arrays. The techniques cov-ered by this Appendix are single12 (fixed angle), E-scan13

(fixed angle), and S-scan14 (sweeping multiple angle).15

In general, this Article is in conformance with SE-2700,Standard Practice for Contact Ultrasonic Testing of WeldsUsing Phased Arrays. SE-2700 provides details to be con-sidered in the procedures used.

IV-420 GENERALThe requirements of Article 4 apply except as modified

by this Appendix.

IV-422 WRITTEN PROCEDURE REQUIREMENTSIV-422.1 Requirements. The requirements of Table

T-421 and Table IV-422 shall apply.

IV-422.2 Procedure Qualification. The requirementsof Table T-421 and Table IV-422 shall apply.

IV-461 INSTRUMENT LINEARITY CHECKSIV-461.2 Amplitude Control Linearity. The ultrasonic

instrument’s amplitude control linearity shall be evalu-ated in accordance with Mandatory Appendix II for eachpulser-receiver circuit.

IV-462 GENERAL CALIBRATION REQUIREMENTSIV-462.7 Focal Law.16 The focal law to be used during

the examination shall be used for calibration.

IV-462.8 Beam Calibration. All individual beamsused in the examination shall be calibrated to providemeasurement of distance and amplitude correction overthe sound path employed in the examination. This shall in-clude applicable compensation for wedge sound path var-iations and wedge attenuation effects.

IV-492 EXAMINATION RECORDFor each examination, the required information of

T-492 and the following information shall be recorded:(a) search unit type, element size and number, and pitch

and gap dimensions(b) focal law parameters, including, as applicable, angle,

focal depth, element numbers used, range of elements, ele-ment incremental change, angular range, and angle incre-mental change

(c) wedge angle

Table IV-422Requirements of a Phased Manual RasterScanning Examination Procedure Using

Linear Arrays

Requirements (As Applicable)EssentialVariable

NonessentialVariable

Search unit(element size and number, and pitchand gap dimensions)

X ...

Focal range(identify plane, depth, or sound path)

X ...

Virtual aperture size(i.e., number of elements, effectiveheight, and element width)

X ...

Wedge angle X ...

Additional E-scan requirementsRange of element numbers used(i.e., 1–126, 10–50, etc.)

X ...

Element incremental change(i.e., 1,2, etc.)

X ...

Additional S-scan requirementsAngular range used(i.e., 40 deg – 50 deg, 50 deg– 70 deg, etc.)

X ...

Angle incremental change(i.e., 1/2 deg , 1 deg, etc.)

X ...

2013 SECTION V ARTICLE 4

75

Copyright ASME International (BPVC) Provided by IHS under license with ASME “X Licensee=BP International/5928366101

Not for Resale, 08/08/2013 10:32:46 MDTNo reproduction or networking permitted without license from IHS

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El ensayo deberá cumplir todas las variables esenciales de ultrasonido convencional (Tabla T-421) y los del apéndice IV, Tabla IV-422

MANDATORY APPENDIX IVPHASED ARRAY MANUAL RASTER EXAMINATION TECHNIQUES

USING LINEAR ARRAYS

IV-410 SCOPEThis Mandatory Appendix describes the requirements

to be used for phased array, manual raster scanning, ultra-sonic techniques using linear arrays. The techniques cov-ered by this Appendix are single12 (fixed angle), E-scan13

(fixed angle), and S-scan14 (sweeping multiple angle).15

In general, this Article is in conformance with SE-2700,Standard Practice for Contact Ultrasonic Testing of WeldsUsing Phased Arrays. SE-2700 provides details to be con-sidered in the procedures used.

IV-420 GENERALThe requirements of Article 4 apply except as modified

by this Appendix.

IV-422 WRITTEN PROCEDURE REQUIREMENTSIV-422.1 Requirements. The requirements of Table

T-421 and Table IV-422 shall apply.

IV-422.2 Procedure Qualification. The requirementsof Table T-421 and Table IV-422 shall apply.

IV-461 INSTRUMENT LINEARITY CHECKSIV-461.2 Amplitude Control Linearity. The ultrasonic

instrument’s amplitude control linearity shall be evalu-ated in accordance with Mandatory Appendix II for eachpulser-receiver circuit.

IV-462 GENERAL CALIBRATION REQUIREMENTSIV-462.7 Focal Law.16 The focal law to be used during

the examination shall be used for calibration.

IV-462.8 Beam Calibration. All individual beamsused in the examination shall be calibrated to providemeasurement of distance and amplitude correction overthe sound path employed in the examination. This shall in-clude applicable compensation for wedge sound path var-iations and wedge attenuation effects.

IV-492 EXAMINATION RECORDFor each examination, the required information of

T-492 and the following information shall be recorded:(a) search unit type, element size and number, and pitch

and gap dimensions(b) focal law parameters, including, as applicable, angle,

focal depth, element numbers used, range of elements, ele-ment incremental change, angular range, and angle incre-mental change

(c) wedge angle

Table IV-422Requirements of a Phased Manual RasterScanning Examination Procedure Using

Linear Arrays



Search unit(element size and number, and pitchand gap dimensions)

X ...

Focal range(identify plane, depth, or sound path)

X ...

Virtual aperture size(i.e., number of elements, effectiveheight, and element width)

X ...

Wedge angle X ...

Additional E-scan requirementsRange of element numbers used(i.e., 1–126, 10–50, etc.)

X ...

Element incremental change(i.e., 1,2, etc.)

X ...

Additional S-scan requirementsAngular range used(i.e., 40 deg – 50 deg, 50 deg– 70 deg, etc.)

X ...

Angle incremental change(i.e., 1/2 deg , 1 deg, etc.)

X ...

2013 SECTION V ARTICLE 4

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Not for Resale, 08/08/2013 10:32:46 MDTNo reproduction or networking permitted without license from IHS--```,`,,``,,`,`````,,,``,`,`,``-`-`,,`,,`,`,,`---

TIPS ULTRASONICOS

El phased array manual, no podrá ser empleada como única técnica en los siguientes casos: §  Inspección de tanques de almacenamiento cuando se requiera

cambiar radiografía por ultrasonido (API 650 o API 620) •  Inspección de recipientes a presión donde se requiera cambiar

radiografía por ultrasonido (ASME SEC VIII, Div. 1) •  Inspección de calderas bajo ASME SEC I •  Inspección de tuberías de proceso bajo el Caso Codigo 181 •  A menos que se indique explícitamente lo contrario por el código

de referencia, se recomienda utilizar el Apéndice Mandatorio VII cuando el estándar de aceptación es basado en “Workmanship” y el Apéndice Mandatorio VIII cuando el estándar de aceptación es basado en “Mecánica de la Fractura”

MANDATORY APPENDIX V PHASED ARRAY E-SCAN AND S-

SCAN LINEAR SCANNING EXAMINATION TECHNIQUES


ASME SEC V

PHASED ARRAY CON ENCODER: APÉNDICE MANDATORIO V

Foto de Jireh-Industries Foto de Jireh-Industries

Se realiza la técnica phased array en configuración Lineal o Sectorial empleando un (1) palpador con encoder. Se requiere realizar un plan de escaneo apropiado al bisel a inspeccionar.


El ensayo deberá cumplir todas las variables esenciales de ultrasonido convencional (Tabla T-421) y los del apéndice V, Tabla V-421

MANDATORY APPENDIX VPHASED ARRAY E-SCAN AND S-SCAN LINEAR SCANNING

EXAMINATION TECHNIQUES

V-410 SCOPE

This Mandatory Appendix describes the requirementsto be used for phased array E-scan13 (fixed angle) andS-scan14 encoded linear17 scanning examinations usinglinear array search units.

V-420 GENERAL

The requirements of Article 4 apply except as modifiedby this Appendix.

V-421.1 Requirements. The requirements of TableT-421 and Table V-421 shall apply.

V-421.2 Procedure Qualification. The requirementsof Table T-421 and Table V-421 shall apply.

V-422 SCAN PLAN

A scan plan (documented examination strategy) shall beprovided showing search unit placement and movementthat provides a standardized and repeatable methodologyfor the examination. In addition to the information inTable V-421, the scan plan shall include beam anglesand directions with respect to the weld axis referencepoint, weld joint geometry, and number of examinationareas or zones.

V-461.2 Amplitude Control Linearity. The ultrasonicinstrument’s amplitude control linearity shall be evalu-ated in accordance with Mandatory Appendix II for eachpulser-receiver circuit.

V-462.7 Focal Law.16 The focal law to be used duringthe examination shall be used for calibration.

V-462.8 Beam Calibration. All individual beams usedin the examination shall be calibrated to provide measure-ment of distance and amplitude correction over the soundpath employed in the examination.

V-467 ENCODER CALIBRATION

A calibration check shall be performed at intervals notto exceed one month or prior to first use thereafter, bymoving the encoder a minimum distance of 20 in.(500 mm). The display distance shall be within 1% ofthe actual distance moved.

V-471.1 Examination Coverage. The required volumeof the weld and base material to be examined shall bescanned using a linear scanning technique with an enco-der. Each linear scan shall be parallel to the weld axis ata constant standoff distance with the beam oriented per-pendicular to the weld axis.(a) The search unit shall be maintained at a fixed dis-

tance from the weld axis by a fixed guide or mechanicalmeans.

Table V-421Requirements of a Phased Array LinearScanning Examination Procedure Using

Linear Arrays



Search unit(s)(element pitch, size, number, and gapdimensions)

X . . .

Focal range(s)(identify plane, depth, or sound pathas applicable)

X . . .

Virtual aperture size(s)(number of elements, element width,and effective height) [Note (1)]

X . . .

Wedge natural refracted angle X . . .Scan plan X . . .Weld axis reference point marking . . . X

Additional E-scan requirements:Rastering angle(s) X . . .Aperture start and stop elementnumbers

X . . .

Aperture incremental change(s)(number of elements stepped)

X . . .

Additional S-scan requirements:Sweep angular range(s) X . . .Angular sweep increment (incrementalangle change, deg)

X . . .

Aperture element numbers (first andlast)

X . . .

NOTE:(1) Effective height is the distance measured from the outside edge of

the first to last element used in the focal law.

2013 SECTION VARTICLE 4

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MANDATORY APPENDIX VPHASED ARRAY E-SCAN AND S-SCAN LINEAR SCANNING

EXAMINATION TECHNIQUES

V-410 SCOPE

This Mandatory Appendix describes the requirementsto be used for phased array E-scan13 (fixed angle) andS-scan14 encoded linear17 scanning examinations usinglinear array search units.

V-420 GENERAL


V-421.1 Requirements. The requirements of TableT-421 and Table V-421 shall apply.

V-421.2 Procedure Qualification. The requirementsof Table T-421 and Table V-421 shall apply.

V-422 SCAN PLAN

A scan plan (documented examination strategy) shall beprovided showing search unit placement and movementthat provides a standardized and repeatable methodologyfor the examination. In addition to the information inTable V-421, the scan plan shall include beam anglesand directions with respect to the weld axis referencepoint, weld joint geometry, and number of examinationareas or zones.

V-461.2 Amplitude Control Linearity. The ultrasonicinstrument’s amplitude control linearity shall be evalu-ated in accordance with Mandatory Appendix II for eachpulser-receiver circuit.

V-462.7 Focal Law.16 The focal law to be used duringthe examination shall be used for calibration.

V-462.8 Beam Calibration. All individual beams usedin the examination shall be calibrated to provide measure-ment of distance and amplitude correction over the soundpath employed in the examination.

V-467 ENCODER CALIBRATION

A calibration check shall be performed at intervals notto exceed one month or prior to first use thereafter, bymoving the encoder a minimum distance of 20 in.(500 mm). The display distance shall be within 1% ofthe actual distance moved.

V-471.1 Examination Coverage. The required volumeof the weld and base material to be examined shall bescanned using a linear scanning technique with an enco-der. Each linear scan shall be parallel to the weld axis ata constant standoff distance with the beam oriented per-pendicular to the weld axis.(a) The search unit shall be maintained at a fixed dis-

tance from the weld axis by a fixed guide or mechanicalmeans.

Table V-421Requirements of a Phased Array LinearScanning Examination Procedure Using

Linear Arrays



Search unit(s)(element pitch, size, number, and gapdimensions)

X . . .

Focal range(s)(identify plane, depth, or sound pathas applicable)

X . . .

Virtual aperture size(s)(number of elements, element width,and effective height) [Note (1)]

X . . .

Wedge natural refracted angle X . . .Scan plan X . . .Weld axis reference point marking . . . X

Additional E-scan requirements:Rastering angle(s) X . . .Aperture start and stop elementnumbers

X . . .

Aperture incremental change(s)(number of elements stepped)

X . . .

Additional S-scan requirements:Sweep angular range(s) X . . .Angular sweep increment (incrementalangle change, deg)

X . . .

Aperture element numbers (first andlast)

X . . .

NOTE:(1) Effective height is the distance measured from the outside edge of

the first to last element used in the focal law.


76



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² Se debe cumplir con los requisitos de ultrasonido convencional, adicional a los del apéndice

² Se requiere realizar una calificación del procedimiento para definir las variables esenciales

² Se debe elaborar un plan de escaneo ² El equipo debe cumplir con los requisitos de Linealidad

en el Control de Amplitud (según apéndice mandatorio II)

² Todas las leyes focales usadas en la calibración deben ser usadas en la inspección

² Cada ley focal individual debe ser calibrada en cuanto a sensibilidad (TCG), empleando el reflector de referencia

REQUISITOS


² Se debe verificar la calibración del encoder en intervalos menores a 1 mes, empleando una distancia de 500 mm. Tolerancia 1% de la longitud verificada

² Se requiere realizar una calificación del procedimiento para definir las variables esenciales

² Se debe evaluar el volumen de la soldadura y ZAC ² El palpador debe mantenerse a una distancia fija de la

mitad de la soldadura, utilizando una guía o medios mecánicos

² El ángulo del E-Scan o el rango de ángulos del S-Scan, debe ser apropiado a la junta a ser examinada.

REQUISITOS, cont.


² La velocidad de escaneo debe ser tal que no se pierdan mas de 2 líneas de datos por pulgada (25 mm).

² Para técnicas basadas en S-Scan, el paso del ángulo no debe ser mayor a 1º

² Para técnicas basadas en E-Scan, el traslape entre aperturas adyacentes debe ser mínimo de 50% de la apertura activa

² Cuando múltiples barridos son empleados, es requerido un traslape de 10% de la apertura efectiva para los E-Scan o el ancho del haz para los S-Scan

² Reflectores transversales pueden ser inspeccionados utilizando UT convencional

REQUISITOS, cont.

TIPS ULTRASONICOS

•  El plan de escaneo se debe validar empleando un software que permita verificar el comportamiento del ultrasonido en la línea de fusión del bisel. Si el haz no es perpendicular a la línea de fusión, este arreglo no detectará la falta de fusión de este bisel

•  La inspección Phased Array según el apéndice V se considera un sistema de adquisición de datos a computador; sin embargo, es muy susceptible de error ya que la distancia del centro de la soldadura al frente de la zapata (index) es muy difícil de mantener; por otra parte, siempre se requiere realizar como mínimo un barrido por cada lado (ver ASME SEC V:2013, par. T-472.1.2) lo cual duplicaría el trabajo comparado con utilizar un escáner con 2 palpadores.

ULTRASONIDO MECANIZADO, EMPLEADO PARA REEMPLAZAR

RADIOGRAFÍA POR ULTRASONIDO

•  Apéndice VII. Inspección Ultrasónica para criterio de aceptación basado en “Workmanship”

•  Apéndice VIII. Inspección Ultrasónica para criterio de

aceptación basado en “Mecánica de la Fractura”

SAUT o AUT PAUT, TOFD, PE

MANDATORY APPENDIX VII ULTRASONIC EXAMINATION

REQUIREMENTS FOR WORKMANSHIP BASED ACCEPTANCE CRITERIA


ASME SEC V

ULTRASONIDO PARA CRITERIO WORKMANSHIP (APÉNDICE VII)

Este apéndice incluye varias técnicas, la inspección se puede realizar combinando técnicas como Phased array, TOFD o Pulso-Eco.

Se requiere el empleo de un escáner automatizado (AUT) o semi-automatizado (SAUT)

TOFD+PE

ENDNOTES : ASME SEC V:2013

18 Workmanship based is defined as a standard for acceptance of a weld based on the

characterization of imperfections by type (i.e., crack, incomplete fusion, incomplete penetration,

or inclusion) and their size (i.e., length).


El ensayo deberá cumplir todas las variables esenciales de ultrasonido convencional (Tabla T-421) y los del apéndice VII, Tabla VII-421

MANDATORY APPENDIX VIIULTRASONIC EXAMINATION REQUIREMENTS FORWORKMANSHIP BASED ACCEPTANCE CRITERIA

VII-410 SCOPE

This Mandatory Appendix provides requirements whenan automated or semi-automated ultrasonic examinationis performed for workmanship based18 acceptancecriteria.

VII-420 GENERAL


VII-421.3 Written Procedure and Procedure Qualifi-cation. The requirements of Table T-421 and TableVII-421 shall apply.

VII-423 PERSONNEL QUALIFICATIONS

Only qualified UT personnel trained in the use of theequipment and who have demonstrated the ability toproperly acquire examination data, shall conduct produc-tion scans. Personnel who analyze and interpret thecollected data shall be a Level II or III who have documen-ted training in the use of the equipment and softwareused.The training and demonstration requirements shall be

addressed in the employer’s written practice.

VII-431 INSTRUMENT REQUIREMENTSThe ultrasonic examination shall be performed using a

system employing automated or semi-automated scanningwith computer based data acquisition and analysis abil-ities. The examination for transverse reflectors may beperformed manually per T-472.1.3 unless the referencingCode Section specifies it also shall be by an automated orsemi-automated scan.

VII-434.2.4 Scanner Block. A block shall be fabri-cated meeting the requirements of T-434.1 andFigure T-434.2.1 except that its thickness, T , shall be with-in the lesser of 1/4 in. (6 mm) or 25% of the material thick-ness to be examined and the number and position of theside-drilled holes shall be adequate to confirm the sensi-tivity setting of each probe, or probe pair in the case of aTOFD setup, as positioned per the scan plan in the scanner.The scanner block is in addition to the calibration block re-quired per Article 4, unless the scanner block also has allthe speci f ied reference ref lectors required perFigure T-434.2.1.

VII-442 SCANNING DATAThe original scanning data, unprocessed, shall be saved

electronically (e.g., magnetic, optical, flash memory, etc.).

VII-466.1 System Confirmation Scan. The scannerblock shall be scanned and the reference reflector indica-tions recorded to confirm system calibration prior to andat the completion of each examination or series of similarexaminations, when examination personnel (except forautomated equipment) are changed, and if the scan planis required to be modified (i.e., VII-483) to satisfy the re-quirements of T-466.3.

VII-466.2 Calibration Checks. The requirements ofT-466.2 are not applicable to this Appendix.

VII-466.2.1 Simulator Checks. The requirementsof T-466.2.1 are not applicable to this Appendix.

VII-471.1 Examination Coverage. The volume to bescanned shall be examined per the scan plan.

Table VII-421Requirements of an Ultrasonic Examination

Procedure for Workmanship BasedAcceptance Criteria

Requirement (as Applicable)EssentialVariable


Scan plan X . . .Computer software X . . .Scanning technique (automated vs.semi-automated)

X . . .

Flaw characterization methodology X . . .Flaw sizing (length) methodology X . . .Search unit mechanical fixturing device(manufacturer and model)

X . . .

Scanner adhering and guidingmechanism

. . . X


78



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MANDATORY APPENDIX VIIULTRASONIC EXAMINATION REQUIREMENTS FORWORKMANSHIP BASED ACCEPTANCE CRITERIA

VII-410 SCOPE

This Mandatory Appendix provides requirements whenan automated or semi-automated ultrasonic examinationis performed for workmanship based18 acceptancecriteria.

VII-420 GENERAL


VII-421.3 Written Procedure and Procedure Qualifi-cation. The requirements of Table T-421 and TableVII-421 shall apply.

VII-423 PERSONNEL QUALIFICATIONS

Only qualified UT personnel trained in the use of theequipment and who have demonstrated the ability toproperly acquire examination data, shall conduct produc-tion scans. Personnel who analyze and interpret thecollected data shall be a Level II or III who have documen-ted training in the use of the equipment and softwareused.The training and demonstration requirements shall be


VII-431 INSTRUMENT REQUIREMENTSThe ultrasonic examination shall be performed using a

system employing automated or semi-automated scanningwith computer based data acquisition and analysis abil-ities. The examination for transverse reflectors may beperformed manually per T-472.1.3 unless the referencingCode Section specifies it also shall be by an automated orsemi-automated scan.

VII-434.2.4 Scanner Block. A block shall be fabri-cated meeting the requirements of T-434.1 andFigure T-434.2.1 except that its thickness, T , shall be with-in the lesser of 1/4 in. (6 mm) or 25% of the material thick-ness to be examined and the number and position of theside-drilled holes shall be adequate to confirm the sensi-tivity setting of each probe, or probe pair in the case of aTOFD setup, as positioned per the scan plan in the scanner.The scanner block is in addition to the calibration block re-quired per Article 4, unless the scanner block also has allthe speci f ied reference ref lectors required perFigure T-434.2.1.

VII-442 SCANNING DATAThe original scanning data, unprocessed, shall be saved

electronically (e.g., magnetic, optical, flash memory, etc.).

VII-466.1 System Confirmation Scan. The scannerblock shall be scanned and the reference reflector indica-tions recorded to confirm system calibration prior to andat the completion of each examination or series of similarexaminations, when examination personnel (except forautomated equipment) are changed, and if the scan planis required to be modified (i.e., VII-483) to satisfy the re-quirements of T-466.3.

VII-466.2 Calibration Checks. The requirements ofT-466.2 are not applicable to this Appendix.

VII-466.2.1 Simulator Checks. The requirementsof T-466.2.1 are not applicable to this Appendix.

VII-471.1 Examination Coverage. The volume to bescanned shall be examined per the scan plan.

Table VII-421Requirements of an Ultrasonic Examination

Procedure for Workmanship BasedAcceptance Criteria




X . . .

Flaw characterization methodology X . . .Flaw sizing (length) methodology X . . .Search unit mechanical fixturing device(manufacturer and model)

X . . .

Scanner adhering and guidingmechanism

. . . X


78



--```,`,,``,,`,`````,,,``,`,`,``-`-`,,`,,`,`,,`---

²  Se debe cumplir con los requisitos de ultrasonido convencional, adicional a los del apéndice

²  Se requiere realizar una calificación del procedimiento para definir las variables esenciales

²  Solo personal calificado como Nivel II o III con entrenamiento documentado en el uso del equipo y software deberá analizar e interpretar la data.

²  Se debe elaborar un plan de escaneo ²  El barrido para la detección de

discontinuidades transversales puede ser realizado de forma automatizada con escaner o manual

²  Se requiere contar con un Bloque de Escaner que permita realizar verificación dinámica de la calibración

REQUISITOS


²  Se almacenará la data sin procesar, en medios magnéticos, ópticos, memorias, etc.

²  Se debe emplear el bloque de escáner para realizar barridos que confirmen la calibración, al inicio y fin de un set de datas.


²  Se debe verificar la presencia de reflectores laminares en el material base y modificar el plan de escaneo de ser requerido.

²  La evaluación final debe realizarse solo después que todos los ajustes han sido realizados (SAFT, contraste, brillo, remoción de onda lateral, etc.

REQUISITOS, cont


²  D i s con t i nu i dade s de tec t ada s mediante la técnica Automatizada (AUT) o semi-automatizada (SAUT), pueden ser a l ternat ivamente evaluadas empleando otras técnicas manuales.

²  El fabricante será el responsable por l a r e v i s i ó n , i n t e r p r e t a c i ó n , evaluación y aceptación del set completo de datas, asegurando el cumplimiento con ASME SEC V, art. 4 y apéndice mandatorio VII

REQUISITOS, cont


TIPS ULTRASONICOS

•  El plan de escaneo se debe validar empleando un software que permita verificar el comportamiento del ultrasonido en la línea de fusión del bisel. Si el haz no es perpendicular a la línea de fusión, este arreglo no detectará la falta de fusión de este bisel

•  El ASME SEC I (calderas), exige que el ensayo de ultrasonido de debe realizar con base en este apéndice (ASME SEC V, Apéndice Mandatorio VII)

•  Este apéndice aplica cuando el código de referencia (diseño), establece los estándares de aceptación en función del tipo de discontinuidad por ejemplo: porosidades, grietas, escorias, falta de fusión, falta de penetración, concavidades internas, etc.

•  Bajo este apéndice se realizan inspecciones de alta calidad ya que contempla la combinación de diferentes técnicas, con el objetivo de mejorar la probabilidad de detección. Podría ser una buena alternativa para proponer en Pipeline bajo API 1104, par. 1.4.7.3 Automated Ultrasonic Weld Testing

MANDATORY APPENDIX VIII ULTRASONIC EXAMINATION

REQUIREMENTS FOR A FRACTURE MECHANICS BASED

ACCEPTANCE CRITERIA


ASME SEC V

ULTRASONIDO PARA CRITERIO MECANICA DE LA FRACTURA(APÉNDICE VIII)

Este apéndice al igual que el VII, incluye varias técnicas, la

inspección se puede realizar combinando técnicas como Phased

array, TOFD o Pulso-Eco. Se requiere el empleo de un escáner

automatizado (AUT) o semi-automatizado (SAUT)

Inspectra, Bolivia

Imagen de Inspectra, Bolivia

ENDNOTES : ASME SEC V:2013

19 Fracture mechanics based is defined as a standard for

acceptance of a weld based on the categorization of imperfections by

type (i.e., surface or subsurface) and their size (i.e., length and through-

wall height).

El ensayo deberá cumplir todas las variables esenciales de ultrasonido convencional (Tabla T-421) y los del apéndice VIII, Tabla VIII-421


MANDATORY APPENDIX VIIIULTRASONIC EXAMINATION REQUIREMENTS FOR A FRACTURE

MECHANICS BASED ACCEPTANCE CRITERIA

VIII-410 SCOPE

This Mandatory Appendix provides requirements whenan automated or semi-automated ultrasonic examinationis performed for fracture mechanics based19 acceptancecriteria.

VIII-420 GENERAL


VIII-421.2 Procedure Qualification. Procedure quali-fication is required per Mandatory Appendix IX.

VIII-421.3 Written Procedure and Procedure Qualifi-cation. The requirements of Table T-421 and TableVIII-421 shall apply.

VIII-423 PERSONNEL QUALIFICATIONSOnly qualified UT personnel trained in the use of the

equipment and who have demonstrated the ability toproperly acquire examination data, shall conduct produc-tion scans. Personnel who analyze and interpret the col-lected data shal l be a Level I I or I I I who havedocumented training in the use of the equipment and soft-ware used.The training and demonstration requirements shall be


VIII-431 INSTRUMENT REQUIREMENTS

The ultrasonic examination shall be performed using asystem employing automated or semi-automated scanningwith computer based data acquisition and analysis abil-ities. The examination for transverse reflectors may beperformed manually per T-472.1.3 unless the referencingCode Section specifies it also shall be by an automated orsemi-automated scan.

VIII-432.1 General. The normal frequency shall be thesame as used in the qualification.

VIII-434.2.4 Scanner Block. A block shall be fabri-cated meeting the requirements of T-434.1 andFigure T-434.2.1 except that its thickness, T , shall be with-in the lesser of 1/4 in. (6 mm) or 25% of the material thick-ness to be examined and the number and position of theside-drilled holes shall be adequate to confirm the sensi-tivity setting of each probe, or probe pair in the case of aTOFD setup, as positioned per the scan plan in the scanner.The scanner block is in addition to the calibration block re-quired per Article 4, unless the scanner block also has allthe speci f ied reference ref lectors required perFigure T-434.2.1.

VIII-442 SCANNING DATA

The original scanning data, unprocessed, shall be savedelectronically (e.g., magnetic, optical, flash memory, etc.).

VIII-466.1 System Confirmation Scan. The scannerblock shall be scanned and the reference reflector indica-tions recorded to confirm that prior to and at the comple-tion of each examination or series of similar examinations,when examination personnel (except for automatedequipment) are changed, and if the scan plan is requiredto be modified (i.e., VIII-483) to satisfy the requirementsof T-466.3.

VIII-466.2 Calibration Checks. The requirements ofT-466.2 are not applicable to this Appendix.

VIII-466.2.1 Simulator Checks. The requirementsof T-466.2.1 are not applicable to this Appendix.

VIII-471.1 Examination Coverage. The volume to bescanned shall be examined per the scan plan.

VIII-471.3 Rate of Search Unit Movement. The rate ofsearch unit movement shall not exceed that qualified.

Table VIII-421Requirements of an Ultrasonic ExaminationProcedure for Fracture Mechanics Based

Acceptance Criteria




X . . .

Flaw sizing (length) methodology X . . .Search unit mechanical fixturing device(manufacturer and model)

X . . .

Scanner and adhering and guidingmechanism

. . . X


80



--```,`,,``,,`,`````,,,``,`,`,``-`-`,,`,,`,`,,`---

MANDATORY APPENDIX VIIIULTRASONIC EXAMINATION REQUIREMENTS FOR A FRACTURE

MECHANICS BASED ACCEPTANCE CRITERIA

VIII-410 SCOPE

This Mandatory Appendix provides requirements whenan automated or semi-automated ultrasonic examinationis performed for fracture mechanics based19 acceptancecriteria.

VIII-420 GENERAL


VIII-421.2 Procedure Qualification. Procedure quali-fication is required per Mandatory Appendix IX.

VIII-421.3 Written Procedure and Procedure Qualifi-cation. The requirements of Table T-421 and TableVIII-421 shall apply.

VIII-423 PERSONNEL QUALIFICATIONSOnly qualified UT personnel trained in the use of the

equipment and who have demonstrated the ability toproperly acquire examination data, shall conduct produc-tion scans. Personnel who analyze and interpret the col-lected data shal l be a Level I I or I I I who havedocumented training in the use of the equipment and soft-ware used.The training and demonstration requirements shall be


VIII-431 INSTRUMENT REQUIREMENTS

The ultrasonic examination shall be performed using asystem employing automated or semi-automated scanningwith computer based data acquisition and analysis abil-ities. The examination for transverse reflectors may beperformed manually per T-472.1.3 unless the referencingCode Section specifies it also shall be by an automated orsemi-automated scan.

VIII-432.1 General. The normal frequency shall be thesame as used in the qualification.

VIII-434.2.4 Scanner Block. A block shall be fabri-cated meeting the requirements of T-434.1 andFigure T-434.2.1 except that its thickness, T , shall be with-in the lesser of 1/4 in. (6 mm) or 25% of the material thick-ness to be examined and the number and position of theside-drilled holes shall be adequate to confirm the sensi-tivity setting of each probe, or probe pair in the case of aTOFD setup, as positioned per the scan plan in the scanner.The scanner block is in addition to the calibration block re-quired per Article 4, unless the scanner block also has allthe speci f ied reference ref lectors required perFigure T-434.2.1.

VIII-442 SCANNING DATA

The original scanning data, unprocessed, shall be savedelectronically (e.g., magnetic, optical, flash memory, etc.).

VIII-466.1 System Confirmation Scan. The scannerblock shall be scanned and the reference reflector indica-tions recorded to confirm that prior to and at the comple-tion of each examination or series of similar examinations,when examination personnel (except for automatedequipment) are changed, and if the scan plan is requiredto be modified (i.e., VIII-483) to satisfy the requirementsof T-466.3.

VIII-466.2 Calibration Checks. The requirements ofT-466.2 are not applicable to this Appendix.

VIII-466.2.1 Simulator Checks. The requirementsof T-466.2.1 are not applicable to this Appendix.

VIII-471.1 Examination Coverage. The volume to bescanned shall be examined per the scan plan.

VIII-471.3 Rate of Search Unit Movement. The rate ofsearch unit movement shall not exceed that qualified.

Table VIII-421Requirements of an Ultrasonic ExaminationProcedure for Fracture Mechanics Based

Acceptance Criteria




X . . .

Flaw sizing (length) methodology X . . .Search unit mechanical fixturing device(manufacturer and model)

X . . .

Scanner and adhering and guidingmechanism

. . . X


80



--```,`,,``,,`,`````,,,``,`,`,``-`-`,,`,,`,`,,`---

²  Se debe cumplir con los requisitos de ultrasonido convencional, adicional a los del apéndice

²  Se requiere realizar una calificación del procedimiento para definir las variables esenciales basado en ASME SEC V, Apéndice Mandatorio IX


²  Se debe elaborar un plan de escaneo ²  El barrido para la detección de

discontinuidades transversales puede ser realizado de forma automatizada con escáner o manual

²  Se requiere contar con un Bloque de Escáner que permita realizar verificación dinámica de la calibración

REQUISITOS


²  Se almacenará la data sin procesar, en medios magnéticos, ópticos, memorias, etc.

²  Se debe emplear el bloque de escáner para realizar barridos que confirmen la calibración, al inicio y fin de un set de datas.


²  Se debe verificar la presencia de reflectores laminares en el material base y modificar el plan de escaneo de ser requerido.

²  La evaluación final debe realizarse solo después que todos los ajustes han sido realizados (SAFT, contraste, brillo, remoción de onda lateral, etc.

REQUISITOS, cont


²  Las dimensiones de las discontinuidades son determinadas por un rectángulo que la contiene. La longitud de la discontinuidad para evaluación será la longitud del rectángulo, la altura será la dimensión del rectángulo que es normal a la superficie que retiene la presión interna.

²  Las discontinuidades serán categorizadas como superficiales y sub-superficiales, no existirán mas categorías.

²  Discontinuidades detectadas durante la inspección automatizada (AUT) o semi-automatizada (SAUT), podrán ser alternativamente evaluadas por técnicas complementarias manuales.

²  El fabricante será el responsable por la revisión, interpretación, evaluación y aceptación del set completo de datas, asegurando el cumplimiento con ASME SEC V, art. 4 y apéndice mandatorio VIII

REQUISITOS, cont


ð13ÞFigure 7.11Single Indications

S a

S ! d

(b) Surface Indication

a

l l

(a) Surface Indication

t t

2d

2a

l

t

S

S > a

(c) Subsurface Indications

737

2013 SECTION VIII, DIVISION 2

Copyright ASME International (BPVC) Provided by IHS under license with ASME Licensee=BP International/5928366101


--`,,`,```,,``,```,,`,````,``-`-`,,`,,`,`,,`---

ð13Þ Figure 7.12Multiple Planar Flaws Oriented in a Plane Normal to the Pressure Retaining Surface

Surface Flaw #1

d2

a

d1

Unclad Surface

(whicheveris

greater)

S < 2d1 or 2d2

S > 0.4a

2d1

2a

Surface Flaw #2

(whicheveris

greater)

S < 2d2 or 2d3(whichever is

greater)

S < 2d1 or 2d2

2d2

2d3

Surface Flaw #3

2d1

2d2

S < 2d1 or 2d2(whichever is greater)

S > 0.4d1

S < 2d3 or 2d2(whichever is greater)

Clad Surface

2d3

2aS > 0.4d3

Pressure Retaining SurfaceOf Unclad Component OrClad-Base Metal InterfaceOf Clad Component

Surface Flaw #5

S < 2d1 or d2(whichever is greater)

2d1 d2

a

Surface Flaw #4

d,d1,d2,d32d1,2d2,2d3 = depths ofindividual flaws

2d1S < 0.4d1 2d2 S > 0.4d2

! = 2a

2a

S < 2d1 or 2d2(whichever is

greater)

!!

!

!

738




--`,

,`,`

``,,

``,`

``,,

`,``

``,`

`-`-

`,,`

,,`,

`,,`

---


REGLA DE INTERACCIÓN DE DISCONTINUIDADES

ð13Þ

ð13Þ

Table 7.9Flaw Acceptance Criteria For Welds With A Thickness Between 13 mm (1/2 in.) And Less Than 25 mm

(1 in.)

Flaw Type l

Surface flaw 0.087 6.4 mm (1/4 in.)

Subsurface flaw 0.143 6.4 mm (1/4 in.)

GENERAL NOTES:(a) The parameter t is the thickness of the weld excluding any allowable reinforcement, and the parameter l is the length of the flaw.

For a butt weld joining two members having different thickness at the weld, t is the thinner of these two thicknesses. If a full pe-netration weld includes a fillet weld, then the thickness of the throat of the fillet weld shall be included in t .

(b) A subsurface indication shall be considered as a surface flaw if the separation (S in Figure 7.11) of the indication from the nearestsurface of the component is equal to or less than half the through dimension (2d in Figure 7.11, Sketch (b)) of the subsurfaceindication.

(c) The acceptance limits specified here are based upon workmanship considerations and are not necessarily intended for use in eval-uating flaws identified after the vessel has gone into service.

(d) a and l are as defined in paragraph 7.5.5.2.

Table 7.10Flaw Acceptance Criteria For Welds With Thickness Between 25 mm (1 in.) And Less Than or Equal to

300 mm (12 in.)

FlawAspect Ratio

25 mm (1 in.) 64 mm (2 1/2 in.) 100 mm (4 in.) 300 mm (12 in.)

Surface Flaw Subsurface Flaw Surface Flaw Subsurface Flaw

0.00 0.031 0.034 0.019 0.020

0.05 0.033 0.038 0.020 0.022

0.10 0.036 0.043 0.022 0.025

0.15 0.041 0.054 0.025 0.029

0.20 0.047 0.066 0.028 0.034

0.25 0.055 0.078 0.033 0.040

0.30 0.064 0.090 0.038 0.047

0.35 0.074 0.103 0.044 0.054

0.40 0.083 0.116 0.050 0.061

0.45 0.085 0.129 0.051 0.069

0.50 0.087 0.143 0.052 0.076

GENERAL NOTES:(a) The parameter t is the thickness of the weld excluding any allowable reinforcement, and the parameter l is the length of the flaw.

For a butt weld joining two members having different thickness at the weld, t is the thinner of these two thicknesses. If a fullpenetration weld includes a fillet weld, then the thickness of the throat of the fillet weld shall be included in t .

(b) A subsurface indication shall be considered as a surface flaw if the separation (S in Figure 7.11) of the indication from the nearestsurface of the component is equal to or less than half the through dimension (2d in Figure 7.11, Sketch (b)) of the subsurfaceindication.

(c) The acceptance limits specified here are based upon workmanship considerations and are not necessarily intended for use inevaluating flaws identified after the vessel has gone into service.

(d) For intermediate flaw aspect ratio and thickness t (64 mm (2–1/2 in.) < t < 100 mm (4 in.)), linear interpolation is permissible.(e) If the acceptance criteria in this table results in a flaw length, l , less than 6.4 mm (0.25 in.), a value of 6.4 mm (0.25 in.) may be

used.(f) For materials exceeding 655 MPa (95 ksi) ultimate tensile strength, the use of this table is limited to a thickness of 200 mm (8 in.).

727




--`,,`,```,,``,```,,`,````,``-`-`,,`,,`,`,,`---


Estándar de aceptación basado en longitud y altura de discontinuidades

TIPS ULTRASONICOS

•  El ASME SEC V, Apéndice Mandatorio VIII aplica cuando se requiere cambiar radiografía por ultrasonido en recipientes a presión (ASME SEC VIII Div.1/Div.2), Tanques de almacenamiento (API 650/API 620), y en piping bajo ASME B31.3 Caso Código 181

•  Este apéndice aplica cuando el código de referencia (diseño), permite emplear estándares de aceptación alternativos, basados en mecánica de la fractura, donde la longitud máxima permisible de una discontinuidad, dependerá de su altura y de la ubicación (superficial o sub-superficial).

•  Es importante verificar requisitos adicionales que son establecidos en el código de referencia, por ejemplo, bajo API 650:2013, toda la evaluación de la data debe ser revisada por un Nivel III, etc.

CAMBIO DE RADIOGRAFÍA POR ULTRASONIDO SEGÚN ASME SEC

VIII Div. 1

ASME SEC VIII Div. 1 2013 ASME Boiler and

Pressure Vessel CodeA N I N T E R N A T I O N A L C O D E

CAMBIO DE RADIOGRAFÍA POR ULTRSAONIDO SEGÚN ASME SEC VIII. Div. 1

La realización del ensayo de radiografía tiene implicaciones de diseño ya que influye en la “Eficiencia de Junta”, por tal motivo, solo se puede cambiar el ensayo de radiografía por ultrasonido, siguiendo lo establecido en UW-51 RADIOGRAPHIC EXAMINATION OF WELDED JOINTS

ð13Þ

ð13Þ

requirements for Inspection and Tests in Subsection C thatpertain to the class of material used. [For tests on reinfor-cing plates, see UG-37(g).]

UW-47 CHECK OF WELDING PROCEDURE

The Inspector shall assure himself that the welding pro-cedure employed in the construction of a vessel has beenqualified under the provisions of Section IX. The Manufac-turer shall submit evidence to the Inspector that the re-quirements have been met.

UW-48 CHECK OF WELDER AND WELDINGOPERATOR QUALIFICATIONS

(a) The Manufacturer shall certify that the welding on avessel has been done only by welders and welding opera-tors who have been qualified under the requirements ofSection IX and the Inspector shall assure himself that onlyqualified welders and welding operators have been used.(b) The Manufacturer shall make available to the In-

spector the record of the qualification tests of each welderand welding operator. The Inspector shall have the right atany time to call for and witness tests of the welding proce-dure or of the ability of any welder and welding operator.

UW-49 CHECK OF POSTWELD HEAT TREATMENTPRACTICE

The Inspector shall satisfy himself that all postweld heattreatment has been correctly performed and that the tem-perature readings conform to the requirements.

UW-50 NONDESTRUCTIVE EXAMINATION OFWELDS ON PNEUMATICALLY TESTEDVESSELS

On welded pressure vessels to be pneumatically testedin accordance with UG-100, the full length of the followingwelds shall be examined71 before the pneumatic test isperformed, for the purpose of detecting cracks:(a) all welds around openings;(b) all attachment welds, including welds attaching non-

pressure parts to pressure parts, having a throat thicknessgreater than 1/4 in. (6 mm).

UW-51 RADIOGRAPHIC EXAMINATION OFWELDED JOINTS

(a) All welded joints to be radiographed shall be exam-ined in accordance with Article 2 of Section V except asspecified below.

(1) A complete set of radiographs and records, as de-scribed in Article 2 of Section V, for each vessel or vesselpart shall be retained by the Manufacturer, as follows:

(-a) films until the Manufacturer’s Data Report hasbeen signed by the Inspector;

(-b) records as required by this Division (10-13).

(2) A written radiographic examination procedure isnot required. Demonstration of density and penetrameterimage requirements on production or technique radio-graphs shall be considered satisfactory evidence of com-pliance with Article 2 of Section V.

(3) The requirements of T-274.2 of Article 2 of Sec-tion V are to be used only as a guide. Final acceptance ofradiographs shall be based on the ability to see the pre-scribed penetrameter image and the specified hole orthe designated wire of a wire penetrameter.

(4) As an alternative to the radiographic examinationrequirements above, all welds in material 1/4 in. (6 mm)and greater in thickness may be examined using the ultra-sonic (UT) method per the requirements of 7.5.5 of SectionVIII, Division 2.(b) Indications shown on the radiographs of welds and

characterized as imperfections are unacceptable underthe following conditions and shall be repaired as providedin UW-38, and the repair radiographed to UW-51 or, atthe option of the Manufacturer, ultrasonically examinedin a c co rdance w i t h t he me thod de s c r i b ed i nMandatory Appendix 12 and the standards specified inthis paragraph, provided the defect has been confirmedby the ultrasonic examination to the satisfaction of theAuthorized Inspector prior to making the repair. For ma-terial thicknesses in excess of 1 in. (25 mm), the concur-rence of the user shall be obtained. This ultrasonicexamination shall be noted under remarks on the Manu-facturer’s Data Report Form:

(1) any indication characterized as a crack or zone ofincomplete fusion or penetration;

(2) any other elongated indication on the radiographwhich has length greater than:

(-a) 1/4 in. (6 mm) for t up to 3/4 in. (19 mm)(-b) 1/3t for t from 3/4 in. (19 mm) to 21/4 in.

(57 mm)(-c) 3/4 in. (19 mm) for t over 21/4 in. (57 mm)where

t = the thickness of the weld excluding any allowable re-inforcement. For a butt weld joining two membershaving different thicknesses at the weld, t is the thin-ner of these two thicknesses. If a full penetration weldincludes a fillet weld, the thickness of the throat of thefillet shall be included in t .

(3) any group of aligned indications that have an ag-gregate length greater than t in a length of 12t , exceptwhen the distance between the successive imperfectionsexceeds 6L where L is the length of the longest imperfec-tion in the group;

(4) rounded indications in excess of that specified bythe acceptance standards given in Mandatory Appendix 4.

UW-52 SPOT EXAMINATION OF WELDED JOINTS

NOTE: Spot radiographing of a welded joint is recognized as an effec-tive inspection tool. The spot radiography rules are also considered tobe an aid to quality control. Spot radiographs made directly after a

2013 SECTION VIII - DIVISION 1UW-46 – UW-52

146

Copyright ASME International (BPVC) Provided by IHS under license with ASME X Licensee=BP International/5928366101


--`,```,,``````,``,`,``,,,,,-`-`,,`,,`,`,,`---


Flujograma para el cambio de radiografía por ultrasonido según ASME SEC VIII Div. 1. (2013)

ð13Þ

(b) All other linear type imperfections are unacceptable if the amplitude exceeds the reference level and the length ofthe imperfection exceeds the following:

(1) 6 mm (1/4 in.) for t less than 19 mm (3/4 in.)(2) for t greater than or equal to 19 mm (3/4 in.) and less than or equal to 57 mm (2-1/4 in.)(3) 19 mm (3/4 in.) for t greater than 57 mm (2-1/4 in.)

In the above criteria, t is the thickness of the weld, excluding any allowable reinforcement (see paragraph 6.2.4.1(d)).For a butt weld joining twomembers having different thicknesses at the weld, t is the thinner of these two thicknesses. If afull penetration weld includes a fillet weld, the thickness of the throat of the fillet shall be included in t .

7.5.5 ULTRASONIC EXAMINATION USED IN LIEU OF RADIOGRAPHIC EXAMINATION7.5.5.1 When used in lieu of the radiographic examination requirements of paragraph 7.5.3, ultrasonic examination

shall be performed in accordance with a written procedure conforming to the requirements of Section V, Article 4, Man-datory Appendix VIII and the following additional requirements. For SAW welds in 21/4 Cr–1Mo–1/4V vessels, ultrasonicexamination is required [see 7.5.4.1(e)].

(a) The ultrasonic examination area shall include the volume of the weld, plus 50 mm (2 in.) on each side of the weld formaterial thickness greater than 200 mm (8 in.). For material thickness 200 mm (8 in.) or less, the ultrasonic examinationarea shall include the volume of the weld, plus the lesser of 25 mm (1 in.) or t on each side of the weld. Alternatively,examination volume may be reduced to include the actual heat affected zone (HAZ) plus 6 mm (1/4 in.) of base materialbeyond the heat affected zone on each side of the weld provided the following requirements are met:

(1) The extent of the weld HAZ is measured and documented during the weld qualification process; and(2) The ultrasonic transducer positioning and scanning device is controlled using a reference mark (paint or low

stress stamp adjacent to the weld) to ensure that the actual HAZ plus an additional 6 mm (0.25 in.) of base metal isexamined.

(b) The initial straight beam material examination (T-472 of Section V, Article 4) for reflectors that could interfere withthe angle beam examination shall be performed:

(1) Manually,(2) As part of a previous manufacturing process, or(3) During the automatic UT examination provided detection of these reflectors is demonstrated.

(c) Personnel performing and evaluating UT examinations shall be qualified and certified in accordance withparagraph 7.3. Only UT Level II or III personnel shall analyze the data or interpret the results.

(d) Contractor qualification records of certified personnel shall be approved by the Certificate Holder and maintainedby their employer.

(e) In addition, personnel who acquire and analyze UT data shall participate in the qualification of the procedure perSection V, Article 4 Mandatory Appendix IX.

(f) Application of automated ultrasonic examinations shall be noted on the Manufacturer's Data Report, as well as theextent of its use.

NOTE: Sectional scans (S-scans) with phased arrays may be used for the examination of welds, provided they are qualified satisfactorily inaccordance with paragraph (e). S-scans provide a fan beam from a single emission point, which covers part or all of the weld, depending on trans-ducer size, joint geometry, and section thickness. While S-scans can demonstrate good detectability from side drilled holes, because they areomni-directional reflectors, the beams can be mis-oriented for planar reflectors (e.g., lack of fusion and cracks.) This is particularly true for thick-er sections, and it is recommended that multiple linear passes with S-scans be utilized for components greater than 25 mm (1 in.) thick. Anadequate number of flaws should be used in the demonstration block to ensure detectability for the entire weld volume.

7.5.5.2 Flaw Sizing. The dimensions of the flaw shall be determined by the rectangle that fully contains the area ofthe flaw (see Figures 7.11 through 7.15).

(a) The length (l) of the flaw shall be drawn parallel to the inside pressure-retaining surface of the component.(b) The depth of the flaw shall be drawn normal to the inside pressure retaining surface and shall be denoted as "a" for

a surface flaw or "2a" for a subsurface flaw.

7.5.5.3 Flaw Evaluation and Acceptance Criteria. Flaws shall be evaluated for acceptance using the applicablecriteria of Tables 7.8, 7.9, 7.10, or 7.11, and with the following additional requirements. Unacceptable flaws shall berepaired and the repaired welds shall be re-evaluated for acceptance.

(a) Surface Flaws - Flaws identified as surface flaws during the UT examination may or may not be surface connected.Therefore, unless the UT data analysis confirms that the flaw is not surface connected, it shall be considered surface con-nected or a flaw open to the surface, and is unacceptable unless surface examination is performed. If the flaw is surfaceconnected, the requirements above still apply. However, in no case shall the flaw exceed the acceptance criteria in thisDivision for the material employed. Acceptance surface examination techniques are as follows:

(1) Magnetic particle examination (MT) in accordance with paragraph 7.5.6,

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ASME SEC VIII Div 2

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(b) All other linear type imperfections are unacceptable if the amplitude exceeds the reference level and the length ofthe imperfection exceeds the following:

(1) 6 mm (1/4 in.) for t less than 19 mm (3/4 in.)(2) for t greater than or equal to 19 mm (3/4 in.) and less than or equal to 57 mm (2-1/4 in.)(3) 19 mm (3/4 in.) for t greater than 57 mm (2-1/4 in.)

In the above criteria, t is the thickness of the weld, excluding any allowable reinforcement (see paragraph 6.2.4.1(d)).For a butt weld joining twomembers having different thicknesses at the weld, t is the thinner of these two thicknesses. If afull penetration weld includes a fillet weld, the thickness of the throat of the fillet shall be included in t .

7.5.5 ULTRASONIC EXAMINATION USED IN LIEU OF RADIOGRAPHIC EXAMINATION7.5.5.1 When used in lieu of the radiographic examination requirements of paragraph 7.5.3, ultrasonic examination

shall be performed in accordance with a written procedure conforming to the requirements of Section V, Article 4, Man-datory Appendix VIII and the following additional requirements. For SAW welds in 21/4 Cr–1Mo–1/4V vessels, ultrasonicexamination is required [see 7.5.4.1(e)].

(a) The ultrasonic examination area shall include the volume of the weld, plus 50 mm (2 in.) on each side of the weld formaterial thickness greater than 200 mm (8 in.). For material thickness 200 mm (8 in.) or less, the ultrasonic examinationarea shall include the volume of the weld, plus the lesser of 25 mm (1 in.) or t on each side of the weld. Alternatively,examination volume may be reduced to include the actual heat affected zone (HAZ) plus 6 mm (1/4 in.) of base materialbeyond the heat affected zone on each side of the weld provided the following requirements are met:

(1) The extent of the weld HAZ is measured and documented during the weld qualification process; and(2) The ultrasonic transducer positioning and scanning device is controlled using a reference mark (paint or low

stress stamp adjacent to the weld) to ensure that the actual HAZ plus an additional 6 mm (0.25 in.) of base metal isexamined.

(b) The initial straight beam material examination (T-472 of Section V, Article 4) for reflectors that could interfere withthe angle beam examination shall be performed:

(1) Manually,(2) As part of a previous manufacturing process, or(3) During the automatic UT examination provided detection of these reflectors is demonstrated.

(c) Personnel performing and evaluating UT examinations shall be qualified and certified in accordance withparagraph 7.3. Only UT Level II or III personnel shall analyze the data or interpret the results.

(d) Contractor qualification records of certified personnel shall be approved by the Certificate Holder and maintainedby their employer.

(e) In addition, personnel who acquire and analyze UT data shall participate in the qualification of the procedure perSection V, Article 4 Mandatory Appendix IX.

(f) Application of automated ultrasonic examinations shall be noted on the Manufacturer's Data Report, as well as theextent of its use.

NOTE: Sectional scans (S-scans) with phased arrays may be used for the examination of welds, provided they are qualified satisfactorily inaccordance with paragraph (e). S-scans provide a fan beam from a single emission point, which covers part or all of the weld, depending on trans-ducer size, joint geometry, and section thickness. While S-scans can demonstrate good detectability from side drilled holes, because they areomni-directional reflectors, the beams can be mis-oriented for planar reflectors (e.g., lack of fusion and cracks.) This is particularly true for thick-er sections, and it is recommended that multiple linear passes with S-scans be utilized for components greater than 25 mm (1 in.) thick. Anadequate number of flaws should be used in the demonstration block to ensure detectability for the entire weld volume.

7.5.5.2 Flaw Sizing. The dimensions of the flaw shall be determined by the rectangle that fully contains the area ofthe flaw (see Figures 7.11 through 7.15).

(a) The length (l) of the flaw shall be drawn parallel to the inside pressure-retaining surface of the component.(b) The depth of the flaw shall be drawn normal to the inside pressure retaining surface and shall be denoted as "a" for

a surface flaw or "2a" for a subsurface flaw.

7.5.5.3 Flaw Evaluation and Acceptance Criteria. Flaws shall be evaluated for acceptance using the applicablecriteria of Tables 7.8, 7.9, 7.10, or 7.11, and with the following additional requirements. Unacceptable flaws shall berepaired and the repaired welds shall be re-evaluated for acceptance.

(a) Surface Flaws - Flaws identified as surface flaws during the UT examination may or may not be surface connected.Therefore, unless the UT data analysis confirms that the flaw is not surface connected, it shall be considered surface con-nected or a flaw open to the surface, and is unacceptable unless surface examination is performed. If the flaw is surfaceconnected, the requirements above still apply. However, in no case shall the flaw exceed the acceptance criteria in thisDivision for the material employed. Acceptance surface examination techniques are as follows:

(1) Magnetic particle examination (MT) in accordance with paragraph 7.5.6,

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CONCLUSIONES

•  Existen varias alternativas para reemplazar radiografía por ultrasonido, pero es importante emplear la metodología apropiada indicada por el código de referencia

•  Tal como lo muestra el ASME SEC VIII, Div 2, API 650 apéndice U, API 620 apéndice U, ASME Caso Código 181, la tendencia de los códigos es a emplear estándares de aceptación alternativos basados en la mecánica de fractura, donde la longitud máxima permisible de las discontinuidades, está en función de la altura de estas. Para lograr apropiadamente realizar este tipo de evaluaciones, es requerido emplear tecnologías con alta probabilidad de detección y precisión en el dimensionamiento, inspectores competentes en las técnicas y procedimientos calificados empleando soldaduras con discontinuidades.

•  Si logramos implementar estas metodologías en nuestros proyectos, estaremos contribuyendo en el cuidado al medio ambiente y la reducción del riesgo.

Datos del Autor

Carlos Enrique Suárez Navas ASNT NDT Level III, AUT DI CSWIP / ISO 9712/EN473

RESUMEN

•  Ingeniero Mecánico con 15 años de experiencia en Ensayos No Destructivos. •  Certificado como ASNT Nivel III en los ensayos de Ultrasonido (UT), Radiografía (RT), Inspección Visual (VT),

Líquidos Penetrantes (PT) y Partículas Magnéticas (MT). •  Certificado en AUT Phased Array Data Interpreter bajo el esquema CSWIP ISO 9712 y EN473 •  Entrenamiento y experiencia en las siguientes tecnologías de AUT y SAUT:

o  ASME CODE COMPLIANT (Eclipse Scientific) o  AUT Olympus Pipewizard o  Advance Phased Array Inspection and Analysis / TOFD Inspection and Analysis o  AGR TD Focus Scan/Handyscan (Phased array On-line, Off-Line Utilities and Data Analysis)

Ha participado en el desarrollo de trabajos empleando tecnologías limpias como AUT y SAUT en proyectos realizados en Perú, Bolivia y Colombia.

Actualmente Director Técnico y Gerente en Integrity & NDT Solutions SAS

Carlos Enrique Suárez Navas ASNT NDT Level III Integrity & NDT Solutions SAS Colombia. Tel. 1-3814946 ext. 101 Cel: 314-2985211 México: Tel. 5541708349 Peru: Tel. 1-7201685, Chile: Tel. 229381208 Email: [email protected] www.integrity-ndt.com

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