Document No Rev. ACCEPTANCE STANDARD FORASME Section IX examination.(QW-191.1.2.2) – Welder and...

Document No Rev. ACCEPTANCE STANDARD FOR RADIOGRAPHICALLY DETERMINED

INDICATIONS IN WELDS ACCORDING TO ASME VIII DIVISION 1 AND ASME IX.

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NON DESTRUCTIVE TEST PLUS di 13 Confidential, Property of NDT PLUS

NDT PLUS Viale Lombardia, 60

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INDEX 1. SUBJECT 2. APPLICABILITY 3. DEFINITIONS 4. REFERENCE DOCUMENTS 5. GENERAL REQUIREMENTS 6. EVALUATION APPENDIX A APPENDIX B



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1. SUBJECT

1.1. This procedure describes the method used to evaluate the weld defects shown by radiographic examination when acceptability according to ASME section VIII division 1 UW-51 or UW-52 and ASME section IX is re-quired.

2. APPLICABILITY

2.1. This procedure is applicable to :

2.1.1. Full penetration butt welds between equal or different thicknesses

2.1.2. Full penetration groove welds.

3. DEFINITIONS

3.1. Thickness "t" :

3.1.1. The thickness of the weld excluding any allowable reinforcement. For a butt weld joining two members having different thicknesses at the weld, t is the thinner of these two thicknesses.

3.1.2. If a groove weld includes a fillet weld, the thickness of the throat of the fillet shall be included in t (see figure 1).

3.2. Rounded indications = indications with a maximum length of 3 times the width. The indications may be circular, elliptical, conical or irregular in shape and may have tails. When evaluating the size of an indication the tail shall be included. The indication may be from any imperfection in the weld, such as porosity, slag or tungsten.

3.3. Isolated rounded indications = Rounded indications separated from an adjacent indication by 1 in. or more.

3.4. Linear indications = indications with a length greater than 3 times the width.

3.5. Aggregate length of the indications in a group = The sum of the dimensions of the indications.

3.6. Dimension of an indication - The maximum dimension of the indication (rounded or elongated)

4. REFERENCE DOCUMENTS

4.1. This procedure satisfies the requirements of the following documents :

• ASME Sect. V – Ed. 2015 : Art. 2 • ASME Sect. VIII Div. 1 Ed. 2015 : Paragraphs UW 51, UW 52 and Appendix 4. • ASME Sect. IX Ed. 2015 : Paragraph QW-191.1.2.2

5. GENERAL REQUIREMENTS

5.1. Before evaluation every film shall be examined for its quality as far as concerns fogging, processing defects, scratches, false indications, density, sensitivity and so on.

5.2. The requirements of T-274.2 of Article 2 of Section V (Ug requirements) are to be used only as a guide. Final acceptance of radiographs shall be based on the ability to see the prescribed penetrameter image and the specified hole or the designated wire of a wire penetrameter.

6. EVALUATION

6.1. Full examination (UW-51) - Indications shown on the welds examined by full radiography and character-ized as imperfections are unacceptable under the following conditions and shall be repaired :

6.1.1. Any type of crack, or zone of incomplete fusion or penetration.

6.1.2. Any other elongated indication on the radiograph which has a length like in the following table.

WELD THICKNESS

(mm) LENGTH

(mm) WELD THICKNESS

(in.) LENGTH

(in.)

t 19 > 6 t 3/4 > 1/4

19 < t 57 > t/3 3/4 < t 2 1/4 > t/3

57 < t > 19 2 1/4 < t > 3/4



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6.1.3. Any group of aligned indications in line that have an aggregate length greater than t in a length of 12t, except when the distance between the successive imperfections exceeds 6L where L is the length of the longest imperfection in the group.

6.1.4. Rounded indications in excess of that specified by the acceptance standard given in Appendix A.

6.2. Spot examination (UW-52) - indications shown on the welds examined by spot radiography and character-ized as imperfections are unacceptable under the following conditions and shall be repaired :

6.2.1. Welds in which the radiograph shows any type of crack, or zone of incomplete fusion or penetration shall be unacceptable.

6.2.2. Welds in which the radiograph shows slag inclusion or cavities shall be unacceptable if the length of any such imperfection is greater than 2/3 t where t is the thickness defined in 3.1.

6.2.3. Multiple aligned indications meeting these acceptance criteria are acceptable when the sum of their longest dimensions indications does not exceed t within a length of 6t (or proportionally for radio-graphs shorter than 6t), and when the longest length L for each indication is separated by a distance not less than 3L from adjacent indications.

6.2.4. Rounded indications are not a factor in the acceptability of welds not required to be fully radi-ographed.

6.3. ASME Section IX examination.(QW-191.1.2.2) – Welder and welding operator performance tests by radi-ography of welds in test assemblies shall be judged unacceptable when the radiograph exhibits any imper-fections in excess of the limits specified below

6.3.1. Linear Indications

a) Any type of crack or zone of incomplete fusion or penetration

b) Any elongated slag inclusion which has a length greater than :

• 3 mm for t up to 10 mm, inclusive • 1/3 t for t over 10 mm to 57 mm, inclusive • 19 mm for t over (57 mm)

c) Any group of slag inclusions in line that have an aggregate length greater than t in a length of 12t , except when the distance between the successive imperfections exceeds 6L where L is the length of the longest imperfection in the group

6.3.2. Rounded Indications

a) The maximum permissible dimension for rounded indications shall be 20% of t or 3 mm, whichever is smaller.

b) For welds in material less than 3 mm in thickness, the maximum number of acceptable rounded in-dications shall not exceed 12 in a 150 mm length of weld. A proportionately fewer number of rounded indications shall be permitted in welds less than 150 mm in length.

c) For welds in material 3 mm or greater in thickness, the charts in Figure B1 represent the maximum acceptable types of rounded indications illustrated in typically clustered, assorted, and randomly dispersed configurations. Rounded indications less than 0.8 mm in maximum diameter shall not be considered in the radiographic acceptance tests of welders and welding operators in these ranges of material thicknesses.



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Sketch (b) = t = tn+tc

Sketch (d) = t = t+tc FIGURE 1



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APPENDIX A

Rounded indications charts acceptance standard for radiographically determined rounded indications in welds

1. APPLICABILITY

1.1. These standards are applicable to ferritic, austenitic and nonferrous materials

2. TERMINOLOGY

2.1. Rounded Indications - Indications with a maximum length of three times the width or less on the radio-graph are defined as rounded indications. These indications may be circular, elliptical, conical, or irregular in shape and may have tails. When evaluating the size of an indication, the tail shall be included. The indica-tion may be from any imperfection in the weld, such as porosity, slag, or tungsten.

2.2. Aligned Indications - A sequence of four or more rounded indications shall be considered to be aligned when they touch a line parallel to the length of the weld drawn through the center of the two outer rounded indications.

2.3. Thickness t - Is the thickness of the weld, excluding any allowable reinforcement. For a butt weld joining two members having different thicknesses at the weld, t is the thinner of these two thicknesses. If a full pen-etration weld includes a fillet weld, the thickness of the throat of the fillet shall be included in t.

3. ACCEPTANCE CRITERIA

3.1. Image Density - Density within the image of the indication may vary and is not a criterion for acceptance or rejection.

3.2. Relevant indications - (see TABLE A1 for example). Only those rounded indications which exceed the fol-lowing dimensions shall be considered relevant.

TABLE A-1. MINIMUM RELEVANT DIMENSIONS

THICKNESS SIZE OF ROUNDED INDICATIONS

THICKNESS SIZE OF ROUNDED INDICATIONS

(mm) (mm) (in.) (in.) t < 3 t/10 t < 1/8 t/10

3 t 6 0.4 1/8 t 1/4 1/64

6 < t 50 0.8 1/4 < t 2 1/32

50 < t 1.6 2 < t 1/16

3.3. Maximum size of rounded indications. (See TABLE A1 for example) The maximum permissible size of any indication is listed in the following table

TABLE A-2 MAXIMUM ALLOWED DIMENSIONS

THICKNESS MAX. SIZE OF ROUNDED INDICATION

THICKNESS MAX. SIZE OF ROUNDED INDICATION

RANDOM ISOLATED RANDOM ISOLATED

(mm) (mm) (mm) (in.) (in.) (in.)

t 16 t/4 t/3 t 5/8 t/4 t/3

16 < t 18 4 t/3 5/8 < t 3/4 5/32 t/3

18 < t 50 4 6 3/4 <t 2 5/32 1/4

50< t 4 10 2 < t 5/32 3/8

3.4. Aligned rounded indications. Aligned rounded indications are acceptable when the summation of the diam-

eters of the indications is less than t in a length of 12t. (See Fig. A1).

3.4.1. The length of groups of aligned rounded indications and the spacing between the groups shall meet the requirement of Fig. A2.



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3.4.2. Spacing. The distance between adjacent rounded indications is not a factor in determining acceptance or rejection, except as required for isolated indications or groups of aligned indications.

3.5. Rounded indication charts. - The rounded indications characterized as imperfections shall not exceed that shown in the charts. The charts in Fig. A3 through Fig. A8 illustrate various types of assorted, randomly dis-persed and clustered rounded indications for different weld thicknesses greater than 3 mm ( 1/8 in ). These charts represent the maximum acceptable concentration limits for rounded indications while the maximum dimensions shall satisfy the limits in table A-2. The charts for each thickness range represent full-scale 150 mm (6 in) radiographs, and shall not be enlarged or reduced. The distributions shown are not necessarily the patterns that may appear on the radiograph, but are typical of the concentration and size of indication permitted.

3.5.1. Weld thickness t less than 3.2 mm (1/8 in). - For t less than 3 mm (1/8 in), the maximum number of rounded indications shall not exceed 12 in a 150 mm (6 in) in. length of weld. A proportionally fewer number of indications shall be permitted in welds less than 150 mm (6 in) in length.

3.5.2. Clustered indications. - The illustrations for clustered indications show up to four times as many indica-tions in a local area, as that shown in the illustrations for random indications. The length of an accepta-ble cluster shall not exceed the lesser of 25 mm (1 in) or 2t. Where more than one cluster is present, the sum of the lengths of the cluster shall not exceed 25 mm (1 in) in a 150 (6 in) length weld.

4. WELDS EXAMINED BY SPOT RADIOGRAPHY

4.1. Rounded indications are not a factor in the acceptability of these welds

TABLE A3 (EXAMPLES)

MAXIMUM SIZE OF ACCEPTABLE ROUNDED INDICATIONS

THICKNESS t RANDOM ISOLATED MAXIMUM SIZE OF NON RELEVANT

INDICATION

mm in. mm in. mm in. mm in.

less than 3 less than 1/8

1/4 t 1/4 t 1/3 t 1/3 t 1/10 t 1/10 t

3 1/8 0.79 0.031 1.07 0.042 0.38 0.015

5 3/16 1.19 0.047 1.60 0.063 0.38 0.015

6 1/4 1.60 0.063 2.11 0.083 0.38 0.015

8 5/16 1.98 0.078 2.64 0.104 0.79 0.031

10 3/8 2.31 0.091 3.18 0.125 0.79 0.031

11 7/16 2.77 0.109 3.71 0.146 0.79 0.031

13 1/2 3.18 0.125 4.27 0.168 0.79 0.031

14 9/16 3.61 0.142 4.78 0.188 0.79 0.031

16 5/8 3.96 0.156 5.33 0.210 0.79 0.031

17 11/16 3.96 0.156 5.84 0.230 0.79 0.031

19 to 50 3/4 to 2 3.96 0.156 6.35 0250 0.79 0.031

over 50 over 2 3.96 0.156 9.53 0.375 1.60 0.063



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(150 mm)

(150

mm)

A-2



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(150 mm)

(150 mm)

A-2



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(150 mm)



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A-2

(150 mm)



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APPENDIX B

FIGURE B1

Document No Rev. ACCEPTANCE STANDARD FORASME Section IX examination.(QW-191.1.2.2) – Welder and...

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