Rt Procedure

1

TABLE OF CONTENT

INDEXPAGE

1.0 Scope

2.0 References

3.0 Definition

4.0 Qualification and Personnel

5.0 Radiographic Equipment

6.0 Preparation

7.0 Location & Datum

8.0 Extent of Inspection

9.0 Cassettes

10.0 Screens

11.0 Film

12.0 Geometric Relationship

13.0 Image Quality Indication ( IQI )

14.0 Sensitivity

15.0 Film Density

16.0 Scattered Radiation

17.0 Radiographic Technique

18.0 Film Processing

19.0 Film Identification

20.0 Viewing Condition

21.0 Interpretation of Radiograph

22.0 Radiographic Report

23.0 Safety

24.0 Acceptance Criteria

APPENDIX

Appendix 1 ( Exposure Technique )

Appendix 2 ( Instruction Technique Sheet )

1

1

1

1 & 2

2

2

2

3

3

3

3

4

4, 5, 6, 7, 8

8

8

8 & 9

9 & 10

10 & 11

12

12

12

1213

13

14

15

1.0 SCOPE

This procedure describes the radiographic techniques to be employed by TWI /CIBD-Johor for the radiography inspection of butt welds in accordance with ASME, Article 2,section V.

2.0 REFERENCES

ASME Sec V Article 2

Atomic Energy Licensing Act 1984

Ionizing Radiation Regulation (Licensing) 1986

Ionizing Radiation Regulation (Basic Safety Standard) 1988

Ionizing Radiation Regulation (Transportation) 1989

Qualification of Personnel- PCN/CSWIP/MLVK/ASNT/ACCP

3.0 DEFINITION

CIDB - Construction Industry Development Board

LPTA- Lembaga Perlesenan Tenaga Atom(Atomic Energy Licensing Board)

NDT- Non Destructive Testing

PCN- Personnel Certification in Non Destructive Testing

CSWIP-Certification Scheme in Welding Inspection Personnel

IQI- Image Quality Indicator

MLVK-Majlis Latihan Vokasional Kebangsaan

ASNT-American Society of Non-Destructive Testing

ACCP-ASNT Central Certification Program

1.0 QUALIFICATION OF PERSONNEL

Radiography inspection work shall be carried out by at least one Radiographer and one Assistant Radiographer.Each technician shall be required to hold the following:

a) Radiographer

A valid LPTA Radiographic Operator license and a current Certificate of Proficiency in Radiography Lev II to a nationally recognized scheme.(MLVK)

b) Assistant Radiographer

Registered with LPTA as a Radiation Worker and a current Certificate of Proficiency in Radiography Lev I or II to a nationally recognized scheme.

c) Radiographic Interpreter

A current Certificate of Proficiency in CSWIP/PCN Radiographic Interpreter Lev II or ACCP RT Lev II or Lev III. Alternative qualifications shall only be acceptable with the prior consent of TWI.

5.0RADIOGRAPHIC EQUIPMENTOnly X-ray units to be usedMuller 260kv Macrotank or equivalent.These may be directional or panaromic units,up to 300kv.

6.0 PREPARATION

Radiographic inspection shall only be carried out on weldment which has been visually inspected and any remedial work necessary has to be completed and accepted by TWI.In addition,Radiographer inspects the weld surface for any irregularities that may mask or confuse interpretation of the final radiograp

7.0LOCATION OF DATUM

All welds will be positively marked datum and each portion under examination shall be positively identified by markings along the length of the weld.

This may be achieved by taking measurements around the circumference from an agreed datum or by means of the clock wise method.For pipes,the datum line shall be positioned,as follows:

For horizontal and inclined pipes,the datum is the highest point in the joint when viewed from the lower numbered joint.

For vertical pipes,the datum is taken from north,when the joint is viewed vertically downwards.

In all cases the datum shall be indelibly marked on the welds. A meter band incorporating lead numerals along the weld shall be utilized to allow positive location of any discontinuity.

8.0 EXTENT OF INSPECTION

Coverage of inspection shall be 100% of weld,Heat Affected Zone & parent material adjacent to weld zone.

9.0 CASSETTES

Flexible envelope cassettes shall be used unless specifically stated otherwise.Ensure close Film-To-Screen and Cassette-To-Object contact.

10.0 SCREENS

Lead intensifying screens shall be used. The front and rear screen thickness shall be 0.125mm unless specified by TWI.

Screen shall be examined on a regular basis for dirt or blemishes which may transfer onto the film thus causing spurious indication which may mask out the actual discontinuity or defect.

11.0 FILM

11.1 Type of Flim

Radiographs shall be made using industrial radiographic film and shall be

selected from Table 1 below.

Class Brand Type

I Agfa

Kodak D4

MX

II Agfa

Kodak D7

CX

11.2 Overlap

Radiographs shall have sufficient overlap to ensure that no portion of weld remains unexamined.There shall be a specific lead marker visible on both radiographs in the area of overlap.

12.0 GEOMETRIC RELATIONSHIP

12.1 The geometric unsharpness is calculated as follows: -

Ug = F x OFD

FOD

F = Focal size

OFD = Object To Film Distance

FOD = Focal To Object Distance

12.2 Geometric Unsharpness of the radiograph shall not exceed the following: -

Material Thickness Ug Maximum(Inches)

Below 2 inches 0.020

2-3 inches 0.030

3-4 inches 0.040

Greater than 4 inches 0.070

13.0 IMAGE QUALITY INDICATOR

13.I ASME Type

The IQI provides a guide to the quality of radiograph produced and in strict compliance with ASME V, shall be appropriately choosen from Table 2 below.A DIN54 109 wire type IQI may be used as an alternative to ASME IQI.

a) Source Side Penetrameter(s)

The penetrameter shall be placed on the source side of the part being examined,except in the condition described in 12.1(b)

b) Film Side Penetrameter

Where inaccessibility prevents hand placing the penetrameters on the source side,it shall be placed on the film side in contact with the part being examined. A lead letter F shall be placed at least as high as the penetrameters indentification number in adjacent to or on the penetrameters but shall not mask the hole.

Radiography shall be performed with a technique that will produce a

sufficient sensitivity from the penetrameter image or specified hole, which are essential to assess the quality of a radiograph. Each radiograph shall display its own identification number.

Penetrameter

DesignationPenetrameter

Thickness,in 1T Hole

Diameter,in 2T Hole

Diameter,in 4T Hole

Diameter,in

5 0.005 0.010 0.020 0.040

7 0.0075 0.010 0.020 0.040

10 0.010 0.010 0.020 0.040

12 0.0125 0.0125 0.025 0.050

15

0.015 0.015 0.030 0.060

17 0.0175 0.0175 0.035 0.070

20 0.020 0.020 0.040 0.080

25 0.025 0.025 0.050 0.100

30 0.030 0.030 0.060 0.120

35 0.035 0.035 0.070 0.140

40 0.040 0.040 0.080 0.160

45 0.045 0.045 0.090 0.180

50 0.050 0.050 0.100 0.200

60 0.060 0.060 0.120 0.240

70 0.070 0.070 0.140 0.280

80 0.080 0.080 0.160 0.320

100 0.100 0.100 0.200 0.400

120 0.120 0.120 0.240 0.480

140 0.140 0.140 0.280 0.560

160 0.160 0.160 0.320 0.640

200 0.200 0.200 0.400 ..

240 0.240 0.240 0.480 ..

280 0.280 0.280 0.560 ..

Table 2: ASME Hole Type IQI Designation

13.2 DIN 54109 Wire Type IQI

The IQI provides a guide to the quality of radiographs produced and shall be appropriately chosen from one of the types recommended in DIN 54109(Table 3) as an alternative to ASME penetrameter.

a) Source Side Penetrameter

The penetrameter shall be placed on the source side of the part being

examined,except in the condition described in 13.2 (b).

b) Flim Side Penetrameter

Where inaccessibility prevents hand placing the penetrameter on the source side it shall be placed on the film side in contact with the part being examined.

A lead letter F at least as high as the penetrameter indentification numbers shall be placed adjacent to the penetrameter.

Radiography shall be performed with a technique that will produce a

sufficient sensitivity from the penetrameter image or specified hole, which are essential to assess the quality of a radiograph. Each radiograph shall display its own identification number.

Table 3: DIN54109 Wire Type IQI Designation

Penetrameter Designation Wire TypeWire Diameter,mm

1-7

1

2

3

4

5

6

7 3.200

2.500

2.000

1.600

1.250

1.000

0.800

6-12

6

7

8

9

10

11

12 1.000

0.800

0.630

0.500

0.400

0.320

0.250

10-16

10

11

12

13

14

15

16 0.400

0.320

0.250

0.200

0.160

0.125

0.100

13.2 Number of Penetrameters

For component where one or more film holders are used for an exposure,at least one penetrameter image shall appear on each radiograph except the following:-

a) For piping or tubular component ,where the source is located at the center of the component and one or more film holders are used for a single exposure of complete circumference(Panaromic Technique),at least three penetrameters shall be spaced approximately 120 apart.

b) For piping or tubular component,where the source is placed on the axis of the object(Double- Wall Double- Image Viewing) and four or more film holders are used for a single section of the circumference,at least three penetrameters shall be used.One penetrameter shall be in the approximate center of the section exposed and one at each end.

c) For piping or tubular component where the source is located at the center of the component (Single-Wall Single-Viewing Technique) and four or more film holders are used for an exposure of a circumference weld,at least three penetrameters shall be used.One penetrameter shall be in the approximate center of the section exposed and one at each end.

14.0SENSITIVITY

14.1 The required sensitivity for each radiograph using ASME Hole Type IQI

is 2-2T or better.ASME Hole Type IQI is calculated using the following

formula:-

IQI Sensitivity = (HT/2) x 100%

Thickness of Penetrated Material In Same Region

H = Diameter of The Smallest Hole Visible on Radiograph

T = Thickness of Penetrameter Used

14.2 The required sensitivity for each radiograph using DIN 54109 Type IQI

is 2% or better.DIN54109 Wire Type IQI is calculated using the

following formula:-

IQI Sensitivity = Diameter of Thinnest Visible Wire On Radiograph x 100%

Thickness of Penetrated Material In Same Region

15.0 FILM DENSITY

For radiographs made with an X-Ray tube,film density will be measured in the area of interest and shall be not less than 1.8 and not greater than 3.0.

For radiographs made with Gamma source,film density will be measured in the area of interest and shall be not less than 2.0 and not greater than 3.0.

16.0 SCATTERED RADIATION

Wherever necessary 6mm thick lead sheet shall be placed behind the film cassette to prevent scattered radiation from fogging the film.

The cassette shall have a lead letter Ba minimum of 12.5mm high, fastened to the back and if a light image of the letter B appears on the film, additional

backing sheets are required. A light image of the letter B shall be called rejection of any radiographic film.

17.0 RADIOGRAPHIC TECHNIQUE

Radiographic Inspection techniques shall be carried out in accordance with the current edition of ASME Section V Article 2.

The specific radiographic parameters to be used shall be detailed on the technique sheets attached to this procedure in Appendix 2.

A single wall exposure technique shall be used for radiography whenever practical. When it is not practical to use a single-wall technique, a double wall technique shall be used.

17.1 Single-Wall Technique

In a single-wall technique, the radiation passes through only one wall of the weld(material),which is viewed for acceptance on the radiograph. An adequate number of exposures shall be made to demonstrate that the required coverage has been obtained.

Note: Appendix 1 Figure 1 & 2 illustrate the single-wall exposure setup that may be used.

17.2 Double-Wall Technique

When it is not practical to use a single wall technique, one of the following double wall technique shall be used.

17.2.1 Single-Wall Viewing

For materials and for weld components, a technique will be used in which the radiation passes through the two walls and only the weld (material) on the film sidewall is viewed for acceptance. An adequate number of exposures shall be made to demonstrate that the required coverage has been obtained.

Wherecomplete coverage is required for circumferential welds (material), a minimum of three exposures taken 120 to each other shall be made.

17.2.2 Double-Wall Viewing

For materials and for welds in components 3-1/2 inch or less in nominal outside diameter, a DWDI technique will be used in which the radiation passes through two walls and the weld (material) in both walls is viewed for acceptance on the same radiograph. For double wall viewing only a source side penetrameter shall be used. Care should be exercised to ensure that the required geometric unsharpness requirement is not exceeded,if so then a single wall viewing shall be used.

a) For welds, the radiation beam will be offset from the plane of the weld at an angle sufficient to separate the images of the source side and film side portions of the weld so that there is no overlap of the areas to be interpreted. When complete coverage is required, a minimum of two exposures taken 90 to each other shall be made for each joint.

b) As an alternative, the weld may be required to be radiographed

with the radiation beam positioned so that the images of both

wall are superimposed. When complete coverage is required a

minimum of three exposures taken at 60( or 120( to each other

shall be made for each joint.

c) Additional exposed shall be made if the required radiographic

coverage cannot be obtained using the minimum number of exposures indicated in a) or b) above.

Note: Appendix 1 Figures 3,4 and 5 illustrate the double-wall exposure setups that

that may be used.

18.0 FILM PROCESSING Processing should be carried out using the standard developer and fixer solution, and shall be in accordance with manufacturers recommendations. The performance of the processing will be checked daily using control strips of X-ray film exposed to a known density and processed. From the developed film, a check is taken and any density change is marked on a process control chart. Upper and lower limits are marked on the chart to provide controls against which the plot can be monitored. The results are interpreted and corrective action taken if necessary. The radiographs shall be free from imperfections due to processing or any other defects which would interfere with interpretation.

18.1.2 Developing

Films will be placed in hangers and immersed in developer solution with constant agitation for even development. Developing time shall be in accordance to that recommended by film manufacturer. It shall normally be 5 min. At 20( C or (68(F). If temperature of the developer varies, development time should be adjusted accordingly.

18.1.2 Stop Bath or Rinse

After development is completed, the film shall be immersed in stop bath or rinsed in clean running water to stop the activity of the developer.

18.1.3 Fixing

Fixing shall be done twice the cleaning time but not more than 15 min. in fresh fixer.

18.1.4 Washing

Washing shall be done with constant flow of clean fresh water. Rate of water flow shall be approximately 5 to 6 times the volume of water tank per hour. After washing, the film shall be rinse in bath of Photo flo (wetting agent) for 1 min to minimize the clinging of water droplets on the films.

18.1.5 Drying

The film shall either be left to dry on the drying racks or dried by the drying machine (Agfa Gavaert Structurix dryer).

18.1.6 Chemical Used

Developer Agfa Structurix G 128

Fixer Agfa Structurix G 328

Film and processing chemical shall be used from the same compatible brand.

19.0 FILM IDENTIFICATIONEach film will be identified by the used of lead symbols to indicate the following minimum information: -

a) The job or workpiece

b) The weld number

c) The section of the weld

d) The date of the test

e) The welders identification

20.0 VIEWING CONDITIONS

The radiographs shall be examined in a darkened room. The radiograph viewer shall provide a light source sufficient for the essential IQI wire/hole to be visible for the specific density range. The light from around the outer edges of the radiographs will be masked.

21.0 INTERPRETATION OF RADIOGRAPHS

A calibrated densitometer or calibrated density strip will be kept in close proximity to the viewer and a spot high-density illuminator will be available. All comment with regard to film quality and interpretation will be recorded on the film folder and on the radiographic report form.

The density of density strips and densitometer calibration shall be verified by comparison with a calibrated step wedge film traceable to a national standard. The densitometer shall be calibrated in accordance with paragraph 5 of SE-1079, Calibration of Transmission Densitometer.

22.0 RADIOGRAPHIC REPORT

Written report shall be prepare giving the result of all the tests performed using the TWI/CIDB Radiographic Report Format containing all relevant information in regards to Radiography Inspection.

23.0 SAFETY

All radiographic work will be carried out in accordance with Statutory Safety Requirement and with TWI/ CIDB (Johor) Sdn. Bhd. Radiation Safety Standing Instructions.

All radiography Inspection work shall be in accordance with LPTA ruling and safety requirement.

24.0 ACCEPTANCE CRITERIA

The ruling code for defects evaluation on plate and piping welds shall be in accordance with ASME IX 1999 edition (Article 1 section QW- 191.2.2)

APPENDIX 1

( EXPOSURES TECHNIQUE )

APPENDIX 2

( INSTRUCTION TECHNIQUE SHEETS)

TECHNIQUE SHEET PAGE 1 of 3

RADIOGRAPHIC EXAMINATION OF WELDS

(PLATE) RT-01

1.0 Material: Carbon Steel or Stainless Steel

2.0 Scope: Applicable to butt weld on plate 6 mm thick and above

3.0 Equipment type: Muller 260 kV Macro tank

4.0 Radiation Source: 2.3 mm x 2.3 mm, 260 kV X-ray machine

5.0 Technicians Qualification:

a) Operator hold valid LPTA Operator License PCN/ CSWIP/ACCP RT Lev.

b) Assistance Operator registered with LPTA as with LPTA as Radiation

worker and hold PCN/ CSWIP/ ACCP RT level

c) Interpreter Holds CSWIP / PCN RI Lev. or ACCP RT Lev. /III

6.0 Technique: Single wall single image (SWSI)

7.0 Geometric relationship: Radiation beam at 90 to weld and film

8.0 Focal to Film Distance: 16 inch or greater

9.0 Film type: Agfa D7 or equivalent grain size

10.0 Film coverage: Film will be equidistance spaced plus 50mm overlap between

Adjacent exposure

11.0 Quantity of film: ) 4 x 10 Length of interest 8

) 4 x 15 Length of interest 13

12.0 Intensifying screen: Lead (Pb) 0.125mm front and rear 0.125mm



(PLATE) RT-01

13.0 Exposure: mAmin x FFD2 FFD1 where mAmin is as follows

Thickness mAmin Kv Ma used

6 mm 21 mAmin 140 Kv 4 mA

9 mm 35 mAmin 140 Kv 4 mA

14.0 Film factor: Change of film from Cx to D7

Film Type Cx D7

Film Factor 2.5 3.5

Film Factor D7 X Original exposure Film Factor CX

Original exposure (plate 6mm) = 1.03 min

New exposure = 3.5 X 1.03

2.5

New exposure time = 1min 26 sec

15.0 Image Quality indicator (IQI): Din 62 Fe wire type, shall be placed on the source

side on each center of the diagnostic length of

radiograph

t < 20mm 10-16

20 < t > 50 mm 6-12

t > 50 mm 1-7

16.0 Geometric Unsharpness: Less than 0.5mm



(PLATE) RT-01

17.0 Processing (manual): Developer - Agfa Structurix G 128

Fixer - Agfa Structurix G 328

Stop bath - Agfa

Photo Flo - Agfa

18.0 Sensitivity: 2 % or better

19.0 Density: Not less than 2.0 and not greater than 3.0 through weld metal

20.0 Acceptance Criteria: ASME 1X 1999 edition (Article 1 section Q rev- 1.91.2.2)

FORMULATED BY: ____________________________ DATE: ______________

Shajahaan Prem

ASNT / ACCP Lev. 115270

APPROVED BY: _____________________________ DATE: ______________

QUALITY ASSURANCE MANAGER



(PIPE above 2- DWSI) RT-02


2.0 Scope: Applicable to butt weld on pipe OD above 2, 7 mm thick and above

3.0 Equipment type: Muller 260 KV Macro tank

4.0 Radiation Source: 2.3 mm x 2.3 mm 260 kV X-ray machine


b) Operator hold valid LPTA Operator License PCN/ CSWIP/ACCP RT Lev.



c) Interpreter Holds CSWIP / PCN RI Lev. or ASNT RT Lev.

6.0 Technique: Double wall single image (DWSI)

7.0 Geometric relationship: Radiations beam offset just outsides weld toe

8.0 Focal to Film Distance: Outside diameter (OD) + distance from focal spot (x)


10.0 Number of exposure: 3 taken of 120 to each other

11.0 Film coverage: Film will be equidistance spaced plus 50mm overlap between

adjacent exposure

12.0 Quantity of film: ) 4 x 10 OD x 3.14 for each exposure

24

) 4 x 15 OD x 3.14 for each exposure

39





14.0 Exposure: mAminX FFD2 FFD1 where Ma-min is as follows

Thickness Ma - min Kv Ma used

7.1 mm 35 mAmin 160 Kv 4 mA

10.97 mm 40 mAmin 180 Kv 4 mA


Film Type Cx D7

Film Factor 2.5 3.5


Original exposure (7.1 mm) = 1.72 min

New exposure = 3.5 x 1.72

2.5

New exposure time = 2 min 24 sec



2.5

New exposure time = 2 min 45 sec




16.0 Image Quality indicator (IQI)

One to three films in single exposure

Din 62 Fe wire type, one on each center of the diagnostic length of radiograph

Four or more film in single exposure

Din 62 Fe wire type, one at center of each section exposed and one at each end.

t < 20mm 10-16

20 < t > 50 mm 6-12

t > 50 mm 1-7




Stop bath - Agfa

Photo Flo - Agfa



21.0 Acceptance Criteria: ASME 1X 199 edition (Article 1 section Q rev- 1.91.2.2) TECHNIQUE SHEET PAGE 4.of 4




Shajahaan Prem


APPROVED BY: _____________________________ DATE: ______________




(PIPE 2 & below- DWDI) RT-03


2.0 Scope: Applicable to butt weld on pipe OD below 2, 5.5 mm thick and above

3.0 Equipment type: Muller 260 KV Macro tank

4.0 Radiation Source: 2.3 mm x 2.3 mm 260 kV X-ray machine


c) Operator hold valid LPTA Operator License PCN/ CSWIP/ACCP RT Lev.



c) Interpreter Holds CSWIP / PCN RI Lev. or ASNT RT Lev.

6.0 Technique: Double wall double image (DWDI)

7.0 Geometric relationship: Radiations beam offset, of local to film distance

approximately 4.

8.0 Focal to Film Distance: 16 or greater


10.0 Number of exposure: 2 taken at 90 to each other

11.0 Quantity of film: One (1) for each exposure





13.0 Exposure: mAminX FFD2 FFD1 where Ma-min is as follows

Thickness Ma - min Kv Ma used

5.5 mm 60 mAmin 140 Kv 4 mA


Film Type Cx D7

Film Factor 2.5 3.5




2.5

New exposure time = 4.14 min




15.0 Image Quality indicator (IQI):

One to three films in single exposure

Din 62 Fe wire type, one on each center of the diagnostic length of radiograph

Four or more film in single exposure

Din 62 Fe wire type, one at center of each section exposed and one at each end.

t < 20mm 10-16

20 < t > 50 mm 6-12

t > 50 mm 1-7




Stop bath - Agfa

Photo Flo - Agfa



20.0 Acceptance Criteria: ASME 1X 199 edition (Article 1 section Q rev- 1.91.2.2)





Shajahaan Prem


APPROVED BY: _____________________________ DATE: ______________


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Rt Procedure