SAEP-1143- 2008
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Engineering Procedure SAEP-1143
1 July 2008
Radiographic Examination Non-Destructive Testing Standards Committee Members Al-Qadeeb, Fathi Essa, Chairman Al-Subaii, Ghazzay Mohammed, Vice Chairman Al-Gahtani, Moraya Saif Al-Motairy, Motlaq Saleem Carswell, Raymond J. Perez, Jaime Paunlagui Scales, Thomas Edward Wescott, Edward Anthony
Saudi Aramco DeskTop Standards Table of Contents 1 2 3 4 5 6 7 8 9 10 11 12
Scope............................................................. 2 Conflicts and Deviations................................ 2 References.................................................... 2 Precautions for Personnel Safety.................. 4 General Requirements................................... 4 Equipment and Materials............................... 5 Examination................................................... 8 Radiographic Exposure Requirements.......... 9 Radiographic Film Interpretation.................. 15 Film Viewing................................................. 15 Final Interpretation of Radiographs.............. 16 Documentation............................................. 16
Figure 1 - Single Wall Radiographic Techniques............. Figure 2 - Double Wall Radiographic Techniques............ Figure 3 - Identification for Film Marker Locations and Arrows...................................... Appendix I - Acceptance Criteria...................................... Attachment 1 - Radiographic Request / Report Forms....
Previous Issue: 29 May 2002
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Next Planned Update: 1 July 2013 Page 1 of 30
Primary contact: Qadeeb, Fathi Essa on 966-3-8720262 Copyright©Saudi Aramco 2008. All rights reserved.
Document Responsibility: Non-destructive Testing Issue Date: 1 July 2008 Next Planned Update: 1 July 2013
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2
SAEP-1143 Radiographic Examination
Scope 1.1
This Engineering Procedure establishes the minimum requirements for performing radiographic examination conducted in accordance with the requirements of the referenced codes/standards.
1.2
This Engineering Procedure applies to Saudi Aramco NDT personnel and to contract personnel seconded to Saudi Aramco on an In-Kingdom Inspection Contract conducting radiographic examination on behalf of Saudi Aramco.
1.3
This SAEP does not apply to radiography performed by out-of-kingdom vendors.
Conflicts and Deviations 2.1
Any conflicts between this procedure and other Saudi Aramco Engineering Standards (SAES's), Materials System Specifications (SAMSS's), Standard Drawings (SASD's), or industry standards, codes, and forms shall be resolved in writing by the Company or Buyer Representative through the Manager, Inspection Department of Saudi Aramco, Dhahran. Direct all requests to deviate from this procedure in writing to the Company or Buyer Representative, who shall follow internal company procedure SAEP-302 and forward such requests to the Manager, Saudi Aramco Inspection Department.
3
References 3.1
Saudi Aramco References Saudi Aramco Engineering Procedures SAEP-302
Instructions for Obtaining a Waiver of a Mandatory Saudi Aramco Engineering Requirement
SAEP-1140
Qual. and Cert. of Saudi Aramco NDT Personnel
SAEP-1141
Industrial Radiation Safety
SAEP-1142
Qual. of Non-Saudi Aramco NDT Personnel
Saudi Aramco General Instruction GI-0150.003
Ionizing Radiation Protection
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SAEP-1143 Radiographic Examination
Saudi Aramco Engineering Form SA 4719-A-ENG 3.2
Radiography Request/Report Sheet
Industry Codes and Standards American Society of Mechanical Engineers ASME B31.1
Power Piping
ASME B31.3
Process Piping
ASME B31.4
Pipeline Transportation Systems for Liquid Hydrocarbons and other Liquids
ASME B31.8
Gas Transmission & Distribution Piping Systems
ASME B46.1
Surface Texture
ASME SEC I
Rules for Construction of Power Boilers
ASME SEC V
Nondestructive Examination
ASME SEC VIII D1
Boiler and Pressure Vessel Code
ASME SEC IX
Welding and Brazing Qualifications
American Welding Society AWS D1.1
Structural Welding Code - Steel
American Petroleum Institute API STD 650
Welded Steel Tanks for Oil Storage
API STD 1104
Welding of Pipelines and Related Facilities
American Society for Testing & Materials ASTM SE-94
Std. Guide for Radiographic Testing
ASTM E-747
Std. Test Method for Controlling Quality of Radiographic Exam Using Wire Penetrameters
ASTM E-1079
Std. Practice for Calibration of Trans. Densitometers
German Standard DIN 54 109
Image Quality of Radiographs
International Organization for Standardization ISO 1027
Radiographic Image Quality Indicators for NDT Principles and Identification Page 3 of 30
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ISO 5580
SAEP-1143 Radiographic Examination
Industrial Radiographic Illuminators - Min. Requirements
Unless otherwise noted, the referenced codes and standards shall be the latest edition. 4
5
Precautions for Personnel Safety 4.1
The materials and/or equipment used during radiographic examination shall comply with SAEP-1141 and GI-0150.003.
4.2
Protective measures shall be taken by radiographic personnel to insure that no individual is exposed to radiation in excess of the prescribed limits as mandated in SAEP-1141 and GI-0150.003.
4.3
All personnel performing radiography for Saudi Aramco or on Saudi Aramco property or concessionaire areas shall have passed the Radiation Safety examination administered by the Saudi Aramco Loss Prevention Department and be in possession of a current Saudi Aramco Radiographer Permit issued by the Inspection Department prior to commencement of radiography.
General Requirements 5.1
All industrial radiography shall be performed in accordance with this procedure. Where radiographic techniques not covered by this procedure are developed, the technique shall be submitted to a Saudi ARAMCO Inspection Department recognized NDT RT Level III for approval prior to implementation.
5.2
Personnel Qualifications
5.3
5.2.1
Saudi Aramco Personnel performing radiography shall be certified in accordance with SAEP-1140.
5.2.2
Contractor personnel performing radiography shall be certified in accordance with SAEP-1142.
5.2.3
All personnel performing Radiographic Film Interpretation (RTFI) shall be certified to level II and have met the requirements of SAEP-1140 or SAEP-1142 as applicable.
Surface Preparation 5.3.1
The weld ripples or weld surface irregularities on both the inside (where accessible) and outside shall be removed by any suitable process to such a degree that any such irregularities appearing on the
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SAEP-1143 Radiographic Examination
resulting radiographic image do not mask nor are confused with the image of any discontinuity.
5.4
5.3.2
Welds shall be visually examined and found acceptable prior to release for radiography.
5.3.3
If the weld is ground flush, markers, such as arrows or V's, pointing toward the centerline of the weld shall be placed on both sides of the weld approximately 0.6 mm (.25 inch) away from the toe of the weld. At least two sets of arrows or V's shall appear on the film; one set near each end of the interpreted area of the film.
Backscatter Radiation A lead letter "B" with minimum dimensions of 13 mm (0.5 inch) in height and 1.5 mm (0.0625 inch) in thickness shall be attached to the back of each film holder during each exposure to determine if backscatter radiation is exposing the film.
5.5
6
When the time of the examination is not specifically stated in the referenced code or project specification, final radiography for acceptance of the weld/material shall be performed after final post weld heat treatment.
Equipment and Materials 6.1
6.2
Acceptable Radiation Sources X-ray generators
(up to 6 MeV)
Iridium 192 (Ir-192)
(up to 200 Ci)
Cobalt 60 (Co-60)
(up to 100 Ci)
Selenium 75 (Se-75)
(up to 50 Ci)
Film 6.2.1
Radiography shall be conducted with industrial radiographic film. Film shall be either Type I or Type II. Film shall be selected to produce radiographs possessing acceptable sensitivity, density, and contrast. Type I film shall be used for radiography of pipe diameters of 8 inch nominal pipe size (NPS) or less.
6.2.2
Radiographic film can be processed either manually or automatically. Processing shall be done in accordance with procedures written to the requirements of ASTM SE-94, Part III, the chemical manufacturer's recommendations, and time and temperature charts. Variation to the film manufacturer's processing recommendations to compensate for Page 5 of 30
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exposure is not permitted. 6.2.3
6.3
6.4
Unexposed film shall be stored on its side or end and protected from the effects of light, pressure, excessive humidity, damaging fumes, vapors, or penetrating radiation. Expired film shall not be used.
Intensifying Screens 6.3.1
Only lead intensifying screens shall be used.
6.3.2
For radiography using gamma ray sources, the minimum thickness of the front lead screen shall be 0.13 mm (0.005 inch) for Ir-192 and Se75 and 0.25 mm (0.010 inch) for Co-60 or the linear accelerator.
6.3.3
Lead screens which are an integral part of "ready pack" (i.e., Pb contact pack) film are acceptable.
6.3.4
Special techniques involving the use of intensifying screens of materials other than lead may be utilized provided the technique is qualified and the density and penetrameter requirements of this procedure are met. Such special techniques shall require prior written approval by a designated Saudi Aramco NDT RT Level III before employed in production radiography.
Image Quality Indicators (IQI) 6.4.1
DIN type penetrameters described in DIN 54 109, ISO type penetrameters described in ISO 1027, or ASTM type penetrameters described in ASTM SE-747/90 shall be used. Tables 1, 2 and 3 show the standard identification numbers found on the penetrameter packs and the wire sizes found in the DIN type, ISO type and ASTM type typical packs. Table 1 – DIN Wire Type Penetrameter
DIN Pack Designation 1 FE DIN
6 FE DIN
10 FE DIN
3.20 (0.125) 1 1.00 (0.040) 6 0.40 (0.016) 10
2.50 (0.098) 2 0.80 (0.032) 7 0.32 (0.013) 11
Wire Diameter mm (inch) Corresponding Wire Number 2.00 1.60 1.25 (0.078) (0.062) (0.050) 3 4 5 0.63 0.50 0.40 (0.024) (0.020) (0.016) 8 9 10 0.25 0.20 0.16 (0.010) (0.008) (0.006) 12 13 14
1.00 (0.040) 6 0.32 (0.013) 11 0.125 (0.004 15
0.80 (0.032) 7 0.25 (0.010) 12 0.1 (0.004) 16
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Table 2 – ISO Wire Type Penetrameter ISO Pack Designation 1 ISO 7
6 ISO 12
10 ISO 16
3.20 (0.125) 1 1.00 (0.040) 6 0.40 (0.016) 10
2.50 (0.098) 2 0.80 (0.032) 7 0.32 (0.013) 11
Wire Diameter mm (inch) Corresponding Wire Number 2.00 1.60 1.25 (0.078) (0.062) (0.050) 3 4 5 0.63 0.50 0.40 (0.024) (0.020) (0.016) 8 9 10 0.25 0.20 0.16 (0.010) (0.008) (0.006) 12 13 14
1.00 (0.040) 6 0.32 (0.013) 11 0.125 (0.004) 15
0.80 (0.032) 7 0.25 (0.010) 12 0.1 (0.004) 16
Table 3 – ASTM Wire Type Penetrameter ASTM Set Designation A
6.5
Wire Diameter mm (inch) .081 (.0032)
.102 (.004) .127 (.005)
.160 (.0063)
.203 (.008) .254 (.010)
B
.254 (.010) .330 (.013) .406 (.016) .508 (.020) .635 (.025) .813 (.032)
C
.813 (.032)
1.016 (.040)
D
2.54 (.100)
3.2 (.126)
6.4.2
Damaged IQIs shall not be used (e.g., bent wires).
6.4.3
IQIs shall be selected from either the same alloy material group or grade as identified in ASTM SE-747 or from an alloy material group or grade with less radiation absorption than the material being radiographed.
1.27 (.050)
1.6 (.063)
2.03 (.080) 2.54 (.100)
4.06 (.160) 5.08 (.200) 6.35 (.250) 8.13 (.320)
Viewing Facilities 6.5.1
The viewing facilities should provide subdued background lighting of an intensity that will not cause troublesome reflections, shadows, or glare on the radiograph.
6.5.2
Radiographic viewers shall meet the minimum requirements set forth in ISO 5580 and shall provide a variable light source for the essential designated wire to be visible for the specified density range.
6.5.3
Light coming from the outer edges of the radiograph or through low density portions of the radiograph shall not interfere with interpretation. Page 7 of 30
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6.5.4
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SAEP-1143 Radiographic Examination
Densitometers shall be used to measure the density of the film. The densitometer shall be calibrated annually in accordance with ASTM SE-1079. Performance shall be verified before each use with a density film strip traceable to a national standard.
Examination 7.1
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. (See Table 4 for Technique and Exposure Requirements) Table 4 – Technique and Exposure Requirements Nominal Pipe Size 3-½" Or Less Above 3-½"
Technique Elliptical Elliptical Superimposed Contact Panoramic
Type of Exposure and Viewing Dbl. Wall Exp. Dbl. Wall Viewing Dbl. Wall Exp. Sgl. Wall Viewing Dbl. Wall Exp. Dbl. Wall Viewing Dbl. Wall Exp. Sgl. Wall Viewing Sgl. Wall Exp. Sgl. Wall Viewing Sgl. Wall Exp. Sgl. Wall Viewing Sgl. Wall Exp. Sgl. Wall Viewing
Min. Num. of Exposures 2 (0,90) 4 (0,90,180,270) 3 (0,60,l20) 3 (0,120, 240)
Location Figure
1
1A
4 (0,90,180,270)
1B or 1C
4
1A, B, C
2F 2E or F 3G 2D or E
Notes: 1. Techniques other than those described in Table 4 may be used with the approval of the Saudi Aramco Inspection Department, NDT Unit, Dhahran. 2. If the minimum number of exposures, shown above, are not adequate to demonstrate the required coverage, additional exposures shall be made as specified by the certified Saudi Aramco film interpreter.
7.2
Single Wall Exposure - Single Wall Viewing (SWE/SWV) Technique - the radiation passes through only one wall of the weld (material), which is viewed on the radiograph for acceptance. (Figure 1)
7.3
Double Wall Exposure - Single Wall Viewing (DWE/SWV) TechniqueRadiation passes through two walls and only the weld (material) on the film side wall is viewed for acceptance on the radiograph. For full weld coverage of circumferential welds at least 3 exposures taken 120° apart shall be taken. (Figure 2) Page 8 of 30
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7.4
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SAEP-1143 Radiographic Examination
Double Wall Exposure - Double Wall Viewing (DWE/DWV) Technique radiation passes through two walls and both walls are viewed for acceptance on the radiograph. These techniques shall only be used for materials and welds in piping 3.5 inch NPS or less. (Figure 2) 7.4.1
Only a source side penetrameter shall be used for the double wall viewing technique.
7.4.2
For the elliptical DWE/DWV technique the radiation beam shall 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. The elliptical technique requires at least 2 exposures 90° to each other for each weld to be radiographed to achieve complete coverage.
7.4.3
In the superimposed DWE/DWV technique, the source shall be at right angles to the weld and the image of both walls are superimposed. The superimposed technique, as a minimum, requires three (3) exposures taken either 60° or 120° to each other for each weld to be radiographed to achieve complete coverage.
Radiographic Exposure Requirements 8.1
8.2
Selection of Radiation Energy 8.1.1
The voltage for examinations with x-ray tubes shall be selected to insure that the required wire is visible on the radiograph.
8.1.2
Gamma Radiation of Ir-192, Se-75 and Co-60 may be used for any material thickness provided the radiographic technique used demonstrates that the required radiographic sensitivity has been obtained. Use of Co-60 is only permitted when the thickness of the material exceeds the practical limits of Ir-192 or Se-75.
Geometric Unsharpness 8.2.1
Geometrical unsharpness, "Ug", equals source size times thickness divided by the object-to-source distance. Ug = Ft/D
(1)
Ug
= Geometrical Unsharpness
F
= Source size, the maximum projected dimension of the radiating source (or effective focal spot) in the plane
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perpendicular to the distance (D) from the weld or object being radiographed.
8.2.2
D
= Distance from source of radiation to weld or other object being radiographed.
t
= Distance from source side of the object being radiographed to the film.
The minimum source to object distance, D, shall be great enough to insure that geometric unsharpness, Ug, of the radiograph does not exceed the values listed in Table 5. Table 5 – Geometrical Unsharpness Material Thickness, mm (Inches)
8.2.3
Ug Maximum mm (Inch)
Under 50.8 (2 in.)
0.500 (0.020 in.)
50.8 - 76.2 (2 in. through 3 in.)
0.760 (0.030 in.)
Over 76.2 - 101.6 (> 3 in. through 4 in.)
1.010 (0.040 in.)
Greater than 101.6 mm (> 4 in.)
1.780 (0.070 in.)
The following formula should be used to determine the minimum source to object distance, D, necessary to insure that the Ug does not exceed the values listed in Table 5. D = (Ft/Ug) + t
8.3
(2)
Location Markers 8.3.1
Each radiograph shall exhibit location markers which appear as radiographic images on the film. The markers shall be placed on the part being examined and not on the exposure holder/cassette. Figures 1, 2, and 3 indicate the recommended placement of location markers. Location markers shall not intrude into the area of interest. 8.3.1.1
The starting point and the direction of numbering shall be identified adjacent to the weld.
8.3.1.2
Number belt spacing around the circumference of the piping shall not exceed the requirements of Table 6. Number belts shall be in "inch" units of measure unless specifically noted on the report.
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Table 6 – Number Belt Spacing NUMBER SPACING Nominal Pipe Size Over 3½ inches through 8 inches
1 inch (2.5 cm) apart
Over 8 inch through 20 inches
4 inches (10 cm) apart Up to the discretion of of the Film Interpreter or Field Supervisor
Over 20 inches
8.4
Spacing
8.3.2
When using a DWE/DWV technique for pipe or tube welds 3.5 inch NPS or less in diameter, the first exposure shall be identified with a lead letter "A" and the second exposure shall be identified with a lead letter "B" (and "C" for third exposure, superimposed).
8.3.3
Location markers shall be identified on the surface of the specimen being radiographed. Regardless of the technique used, the area of interest of the radiograph shall be accurately traceable to its location on the part until acceptance.
8.3.4
Station or location markers (i.e., numbers) shall be spaced in inches or centimeters, with the unit of measure clearly identified on the RT report.
8.3.5
For pipe or tube welds greater than 3.5 inch NPS, a number belt shall be used. The number belt shall consist of lead numbers between 6 mm (0.25 inch) and 12 mm (0.5 inch) in height.
Film Identification 8.4.1
8.4.2
Each radiograph shall be permanently identified using lead numbers and/or letters. The radiographic identification shall include the following information: •
JO number or BI number
•
Component, vessel, or piping identification
•
Seam or weld identification
•
R1 for Repair, if necessary; R2, etc., if more than one repair. Cutouts shall be identified as a new weld, e.g., NW1, etc.
•
Date of radiography
Radiographs misidentified may be re-identified, with correction tape or equivalent, only when the Saudi Aramco film interpreter or field
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supervisor has determined that it is impractical to re-radiograph. Reidentification of radiographs shall be noted on the inspection report. 8.5
Penetrameter (IQI) Selection 8.5.1
Penetrameters shall be wire type penetrameters and shall be selected to insure that the designated wire required by Table 7 shall be included in the penetrameter pack used. When possible the penetrameter shall be selected to insure that there exists wires both above and below the designated wire.
8.5.2 Welds with Reinforcement - Selection of the penetrameter shall be based on the nominal thickness of the base material plus the estimated weld reinforcement not to exceed the maximum permitted by the referencing code section. Internal protrusion of single bevel welds, backing rings or strips shall not be considered as part of the thickness in penetrameter selection. In general, the following applies:
8.5.3
8.5.2.1
SWE/SWV or DWE/SWV techniques - the required wire size is based on the wall thickness plus one reinforcement where such reinforcement is not ground off.
8.5.2.2
DWE/DWV elliptical technique - the required wire size is based on two wall thickness plus one reinforcement where such reinforcement is not ground off.
8.5.2.3
DWE/DWV superimposed technique - the required wire size is based on two wall thickness plus two reinforcements were such reinforcement is not ground off.
Welds without Reinforcement - the thickness on which the penetrameter is based is the nominal single wall thickness for SWE/SWV and the nominal double wall thickness for DWE/DWV technique.
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Table 7 – IQI Selection Unless otherwise stated in the Scope of Work, penetrameters shall be selected as shown in the following columns. Nominal Material Thickness Source Side Film Side inch
8.6
mm
Wire Number Wire Number
Up to 0.25, incl.
Up to 6, incl
13
14
Over 0.25 through 0.375
6 through 10
12
13
Over 0.375 through 0.50
10 through l2
11
12
Over 0.50 through 0.75
l2 through 18
10
11
Over 0.75 through 1.00
18 through 25
9
10
Over 1.00 through 1.50
25 through 40
8
9
Over 1.50 through 2.00
40 through 50
7
8
Over 2.00 through 2.50
50 through 60
6
7
Over 2.50 through 4.00
60 through 100
5
6
Over 4.00 through 6.00
100 through 150
4
5
Over 6.00 through 8.00
150 through 200
2
4
Over 8.00 through 10.00
200 through 250
1
2
Penetrameter (IQI) Placement 8.6.1
Source side penetrameter(s) shall be used at all times unless placement of the penetrameter(s) on the source side of the object is not possible.
8.6.2
When film side penetrameters are used, the penetrameters shall be in contact with the part being examined. A lead letter "F", as least as high as the penetrameter identification numbers, shall be placed adjacent to or on each penetrameter and shall not interfere with the penetrameter or be in an area of interest.
8.6.3
When configuration or size prevents placing the penetrameter(s) on the part or weld, the penetrameter(s) may be placed on a separate block of radiographically similar material. The block shall be placed as close as possible to the item being examined, and the resulting radiographic density of the block image shall be within the prescribed penetrameter/area of interest density variation tolerances as stated in paragraph 8.4. Refer to an Inspection Department recognized NDT RT Level III for evaluation of radiographically similar material.
8.6.4
The penetrameters shall be placed perpendicular across the weld. ID numbers and, when used, the lead letter "F", shall not be in the area of Page 13 of 30
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interest. Where placement of the penetrameter across the weld or area of interest is not possible refer to the paragraphs above and/or refer to an Inspection Department recognized NDT RT Level III for clarification.
8.7
8.6.5
Penetrameter Location for Materials other than Welds - The penetrameter(s) with the penetrameter identification number(s), and, when used, the lead letter "F", may be placed in the area of interest.
8.6.6
For piping 3.5 inch NPS and less, when using the DWE/SWV technique, only that portion of the weld adjacent to the film, when the penetrameter is placed on the film side of the object, may be viewed for acceptance for the radiographic technique.
Number of Penetrameters 8.7.1
For DWE/SWV or SWE/SWV techniques requiring multiple exposures for complete inspection of the weld, and where the length of the film to be interpreted is greater than 127 mm (5 inches), two penetrameters placed across the weld and perpendicular to the weld length shall be used. One shall be within 25.4 mm (1 inch) of the end of the film length to be interpreted and the other shall be at the center of the film length to be interpreted. When the film length to be interpreted is 127 mm (5 inches) or less, one penetrameter shall be placed across the weld and perpendicular to the weld length at the center of the length to be interpreted.
8.7.2
If more than two penetrameters are used because of density requirements, one shall be placed in the lightest area of interest and the other in the darkest area of interest. The intervening densities on the radiograph shall be considered as having acceptable density.
8.7.3
When a complete circumferential weld is radiographed in a single exposure using a source inside the piping, i.e., panoramic radiography, at least four (4) penetrameters shall be used and placed perpendicular to the weld and spaced equally around the circumference.
8.7.4
When an array of objects in a circle is radiographed, at least one penetrameter shall show on each radiograph.
8.7.5
Where portions of longitudinal welds adjoining the circumferential weld are being examined simultaneously with the circumferential weld, additional penetrameters shall be placed on the longitudinal weld at the ends of the welds being radiographed.
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SAEP-1143 Radiographic Examination
Radiographic Film Interpretation 9.1
All radiographs shall be free from mechanical, chemical, or other blemishes to the extent that they do not mask and are not confused with the image of any discontinuity in the area of interest. Such blemishes include, but are not limited to; fogging, processing defects such as streaks, watermarks, or chemical stains, scratches, finger marks, crimps, dirt, static marks, smudges, or false indications due to defective screens.
9.2
One sheet of film shall be used for each exposure. If an area of interest contains an artifact a second exposure shall be made.
9.3
Radiographic Film Density - For Gamma radiography the minimum density shall be 2.0. For X-radiography, the minimum density shall be no less than 1.8. Radiographic film density through the area of interest or adjacent to the designated wire type penetrameter shall be no greater than 4.0 for radiographs produced by Gamma Rays or X-rays.
9.4
Density Variation 9.4.1
Radiographic density anywhere through the area of interest shall not vary more than -15% and +30% from the measured density next to the designation wire of the penetrameter. If density variation exceeds the permissible -15% and +30% range, additional penetrameters shall be used for each exceptional area or areas and the area of interest reradiographed.
9.4.2
The maximum permissible +30% may be exceeded for penetrameters with shims provided penetrameter sensitivity meets the requirements of this SAEP.
9.5
IQI Sensitivity - Acceptance of the radiograph for sensitivity is based on ability of the radiograph to display the required wire on the penetrameter, viewed across the weld, and the penetrameter identifying numbers and letters. Radiographs not meeting this requirement shall be re-radiographed.
9.6
Back Scatter Radiation - Radiographic film displaying a light image of the letter "B" on a darker background shall be cause for rejection of the radiograph. A dark image of the letter "B" on a lighter background shall be considered acceptable.
Film Viewing 10.1
Film shall be viewed in an area with subdued lighting as required by paragraph 6.5.1. Page 15 of 30
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SAEP-1143 Radiographic Examination
10.2
Personnel interpreting radiographs shall allow 3 minutes in any darkened area for their eyes to adjust if coming into the darkened area from normal room light and at least 5 minutes if coming in from full sunlight.
10.2
Radiographs shall be interpreted only in those areas in which the penetrameter(s) have established that a suitable radiographic technique has been used.
10.3
Composite viewing of double film exposure is not permitted unless approved in writing by an Inspection Department approved NDT RT Level III.
10.4
Each exposed film shall be properly stored to prevent damage to the film.
Final Interpretation of Radiographs 12.1
The radiographs shall be examined and interpreted for film quality and for discontinuities by personnel certified to perform RTFI by Saudi ARAMCO.
12.2
The film interpreter shall record on a review form (Attachment 1) accompanying the radiographs, the type of defects present on each radiograph and the area(s) rejected.
Documentation 12.1
Radiography reports shall be issued using Saudi Aramco form 4719-A-ENG "Radiography Request & Report Sheet" (Attachment 1). As a minimum, the report shall include: 12.1.1
Report number, date, BI or JO number, names and Saudi Aramco badge numbers of the radiographers, and the governing acceptance criteria.
12.1.2
Weld Identification number and orientation of individual films which clearly shows the sequence of exposures, location of weld and component designation.
12.1.3
Radiation source, type, strength, and size.
12.1.4
The radiographic interpreter's full name and Saudi Aramco badge number. Note: Any individual interpreting or reviewing the film shall insure that their identification, meeting the requirement of this paragraph, is recorded on the form. Initials, either on Saudi
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Aramco Form 4719-A-ENG or on the film envelope, are not acceptable.)
12.2
12.3
1 July 2008
12.1.5
Film brand, type, and processing method,
12.1.6
IQI and designated wire.
12.1.7
Legible signature of all personnel interpreting or reviewing the film.
The following information shall either be provided on each film jacket or on the final report noted above. 12.2.1
Shooting sketch showing the geometric arrangement of source, weld, film, penetrameters, shims, and location markers, or technique shooting sketch may be listed from this document.
12.2.2
Exposure time.
12.2.3
Source to weld or object distance.
12.2.4
Effective focal spot of the radiation source.
12.2.5
Calculated geometric unsharpness when required.
12.2.6
Weld thickness.
Final disposition of the radiographs and records shall be in accordance with the following. 12.3.1
Radiographs shall be turned over to the proponent upon completion of the work.
12.3.2
The radiographs may be retained at the proponent's facilities or turned over to Saudi Aramco's Management Records Group. Refer to "Records Management Manual, Part II, Section 2.
Revision Summary Revised the "Next Planned Update". Reaffirmed the contents of the document, and reissued with no other changes.
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Figure 1 – Single Wall Radiographic Techniques IQI Placement Side Source side if accessible, film side if not
Location Marker Placement Either Side
Single Wall
Source Side
Source Side
Single Wall
Source Side
Source Side
Pipe OD
Exposure Technique
Radiographic Viewing
≥ 12"
Single Wall
Single Wall
≥ 12"
Single Wall
Any
Single Wall
End View
Side View
Note: The above sketches are standard techniques. Other exposure arrangements may be made provide the Saudi Aramco Inspection Department, NDT Unit, approves them.
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Figure 2 – Double Wall Radiographic Techniques Pipe OD
Exposure Technique
Any
Double Wall, at least 4 exposures 90° to each other for complete coverage
Any
Double Wall, at least 4 exposures 90° to each other for complete coverage
3-½" or less
Double Wall, at least 2 exposures at 90° to each other for complete coverage
Radiographic Viewing Single Wall
IQI Placement Side Either Side
Location Marker Placement Film Side
Single Wall
Either Side
Film Side
Double Wall: (Ellipse) Read offset source side and film side images
Source Side
Either Side
End View
Side View
Note: The above sketches are standard techniques. Other exposure arrangements may be made with documented Saudi Aramco Inspection Department NDT RT Level III approval.
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Figure 2 (Con't) – Double Wall Radiographic Techniques Pipe OD
Exposure Technique
3-½" or less
Double Wall, at least 3 exposures at 60° or 120° to each other for complete coverage
Radiographic Viewing Double Wall: Read Superimposed source and film side images
End View
Side View
IQI Placement Side Source Side
Location Marker Placement Either Side
Note: The above sketches are standard techniques. Other exposure arrangements may be made with documented Saudi Aramco Inspection Department NDT RT Level III approval.
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Figure 3 – Identification for Film Marker Locations & Arrows
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Appendix I – Acceptance Criteria
The following tables are provided as a guide only. Code or contract governs
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ASME SEC I, Paragraph PW-51, ASME SEC VIII D1, ASME B31.1, Paragraph 136.4.5, API STD 650 Table 1-1 – Maximum Discontinuity Size Allowed ASME SEC I; ASME B31.1
Crack
None
ASME SEC VIII D1, Para. UW-51; API STD 650 None
Lack of Fusion
None
None
None
Incomplete Penetration
None
None
None
Elongated Indications
6.0 mm (¼") for t up to 19.0 mm (¾") inclusive; 1/3t for t from 19.0 mm (¾") to 57.0 mm (2¼") inclusive; 19 mm (¾") for t over 57 mm (2¼")
6.0 mm (¼") for t up to 19.0 mm (¾"); 1/3t for t from 19.0 mm (¾") to 57.0 mm (2¼") inclusive; 19 mm (¾") for t over 57 mm (2¼")
2/3 t where t is the thickness of the weld excluding allowed reinforcement
Defect
Group of Aligned Indications
aggregate length greater than t in a length of 12t, except when the distance between successive indications exceeds 6L where L is the longest indication in the group
aggregate length greater than t in a length of 12t, except when the distance between successive indications exceeds 6L where L is the longest indication in the group
Porosity & Rounded Indications
Refer to Table 2-2 of this Appendix
Refer to Table 2-2 of this Appendix
Tungsten
Refer to Table 2-2 of this Appendix
Refer to Table 2-2 of this Appendix.
Root Concavity
Unacceptable if the density is greater than that of the parent material.
ASME SEC VIII D1, Paragraph UW-52 None
the sum of the longest dimensions of all such indications is < t in a length of 6t & the longest indications are separated by 3L where L is the length of the longest indication. The maximum length of acceptable indication shall be ¾". Any such indication shorter than ¼" shall be acceptable for any plate thickness. Round indications are not a factor unless 100% examination is required. Rounded tungsten inclusions are to be evaluated as rounded indications per UW-51. Elongated and aligned tungsten inclusions are unacceptable.
Rounded Indications shall be judged against the standards set forth in ASME SEC VIII D1, Appendix 4.
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ASME B31.3 The type of weld joints and service conditions shall be considered to determine the method of NDE required. Table 2-1 is to be used with all notes and is included with this SAEP for radiographic film interpretation. Porosity - Refer to Table 1.1 of this appendix.
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Table 2-2 – Acceptance Criteria for Table 2-1 Symbol
Measure
Acceptable Value Limits (Note 6)
A
Extent of imperfection
Zero (no evident imperfection)
B
Depth of incomplete penetration
≤ 0.8 mm (1/32 in.) and ≤ 0.2Tw
Cumulative length of incomplete penetration
≤ 38 mm (1.5 in.) in any 150 mm (6 in.) weld length
Depth of lack of fusion and incomplete penetration Cumulative length of lack of fusion and incomplete penetration [Note (7)] Size and distribution of internal porosity Size and distribution of internal porosity
≤ 0.2Tw
C
D E
F
G
Slag inclusion or elongated indication Individual length Individual width Cumulative length Slag inclusion or elongated indication Individual length Individual width Cumulative length
≤ 38 mm (1.5 in.) in any 150 mm (6 in.) weld length See BPV Code, Section VIII, Division 1, Appendix 4 For Tw ≤ 6.4 mm (¼ in.), limit is same as D For Tw > 6.4 mm (¼ in.), limit is 1.5 X D ≤ Tw/3 ≤ 2.4 mm (3/32 in.) and ≤ Tw/3 ≤ Tw in any 12Tw weld length ≤ 2Tw ≤ 3.2 mm (1/8 in.) and ≤Tw/2 ≤ 4Tw in any 150 mm (6 in.) weld length
H
Depth of undercut
≤ 0.8 mm (1/32 in.) and ≤Tw/4
I
Depth of undercut
≤ 1.6 mm (1/16 in.) and ≤Tw/4 or 0.8 mm (1/32 in.)
J
Surface roughness
< 500 min. Ra per ASME B46.1
K
Depth of root surface concavity
L
Height of reinforcement or internal protrusion [Note (8)] in any plane through the weld shall be within limits of the applicable height value in the tabulation at right. Weld metal shall merge smoothly into the component surfaces.
Total joint thickness, incl. weld reinf., ≥ Tw For Tw mm (in.) Height, mm (in.) ≤ 6.4 (¼) ≤ 1.6 (1/16) > 6.4 (¼), ≤ 12.7 (½) ≤ 3.2 (1/8) > 12.7 (½), ≤ 25.4 (1) ≤ 4.0 (5/32) > 25.4 (1) ≤ 4.8 (3/16)
M
Height of reinforcement or internal protrusion [Note (8)] as describe in L
Limit is 2L
**
Tungsten Inclusions
To be evaluated as rounded indications. Elongated or aligned tungsten inclusions are unacceptable.
Tw = Nominal wall thickness of the thinner of two components joined by a butt weld. Notes: (1)
Criteria given are for required examination. More stringent criteria may be specified in the engineering design. See also paragraphs. 341.5 and 341.5.3 of ASME/ANSI B31.3
(2)
Longitudinal groove weld includes straight and spiral seam. Criteria are not intended to apply to welds made in accordance with a standard listed in Table A-I or Table 326.1 of ASME B31.1.
(3)
Fillet weld includes socket and seal welds, and attachment for slip-on flanges and branch reinforcement.
(4)
Branch connection weld includes pressure containing welds in branches and fabricated laps.
(5)
These imperfections are evaluated only for welds 5 mm (3/16 in.) in nominal thickness.
(6)
Where two limiting values are separated by "and", the lesser of the values determines acceptance. Where two sets of values are separated by "or", the larger value is acceptable.
(7)
Tightly butted unfused root faces are unacceptable.
(8)
For groove welds, height is the lesser of the measurements made from the surfaces of the adjacent components. For fillet welds, height is measured from the theoretical throat, Fig. 328.5.2A, of ASME/ANSI B31.3 internal protrusion does not apply.
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API STD1104, ASME/ANSI B31.4, ASME/ANSI B31.8 Table 3-1 is applicable in determining the size and type of discontinuities when viewing radiographs for final acceptance in accordance with API STD 1104, ASME/ANSI B31.4, Paragraph 434.8.5, and ASME/ANSI B31.8. Table 3-1 – Acceptance Criteria for API STD 1104 Indication/Defect Inadequate Penetration (IP) (without high-low) Inadequate Penetration due to High-Low (IPD)
Incomplete Fusion (IF)
Incomplete Fusion due to Cold Lap (IFD) Internal Concavity (IC)
Burn-Through (BT)
Unacceptable if any of the following conditions exist: 1. Length of an individual indication of IP exceeds 25.4 mm (1.0"). 2. The aggregate length of indications of IP in any continuous 304.8 mm (12") length of weld exceeds 25.4 mm (1.0"). 3. The aggregate length of indications of IP exceeds 8% of the weld length in any weld less than 304.8 mm (12") in length. 1. Length of an individual indication of IPD exceeds 50.8 mm (2.0"). 2. The aggregate length of indications of IP in any continuous 304.8 mm (12") length of weld exceeds 76.2 mm (3.0"). 1. Length of an individual indication of IF exceeds 25.4 mm (1.0"). 2. The aggregate length of indications of IF in any continuous 304.8 mm (12") length of weld exceeds 25.4 mm (1.0"). 3. The aggregate length of indications of IF exceeds 8% of the weld length in any weld less than 304.8 mm (12") in length. 1. Length of an individual indication of IFD exceeds 50.8 mm (2.0"). 2. The aggregate length of indications of IFD in any continuous 304.8 mm (12") length of weld exceeds 50.8 mm (2.0"). 3. The aggregate length of indications of IFD exceeds 8% of the weld length. Any length of IC is acceptable provided the density of the radiographic image of the IC does not exceed that of the thinnest adjacent base metal. For areas that exceed the density of the thinnest adjacent base metal, the criteria for burn through are applicable. Pipe OD ≥ 2-3/8" 1. Maximum dimension exceeds 6.35 mm (¼") and the density of the BT's image exceeds that of the thinnest adjacent base metal 2. Maximum dimension exceeds the thinner of nominal wall thicknesses joined, and the density of the BT's image exceeds that of the thinnest adjacent base metal 3. Sum of maximum dimensions of separate BTs whose image density exceeds that of the thinnest adjacent base metal exceeds 12.7 mm (½") in 304.8 mm (12") of weld or the total weld length, whichever is less.
Pipe OD < 2-3/8" 1. Maximum dimension exceeds 6.35 mm (¼") and the density of the BT's image exceeds that of the thinnest adjacent base metal 2. Maximum dimension exceeds the thinner of nominal wall thicknesses joined, and the density of the BT's image exceeds that of the thinnest adjacent base metal 3. More than one BT of any size is present and the density of more than one of the images exceeds that of the thinnest adjacent base metal.
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Table 3-1 – Acceptance Criteria for API STD 1104 (Cont'd) Indication/Defect
Unacceptable if any of the following conditions exist:
Slag Inclusions Elongated (ESI) Isolated (ISI) Note: ESI indications separated by approx. width of root bead (wagon tracks) to be considered as a single indication unless the width of either > 1/32". In that event, they shall be considered as separate indications.
Pipe OD ≥ 2-3/8" Unacceptable if: 1. ESI length > 2" 2. ESI width > 1/16" 3. Sum of the lengths of ISI > ½" in 12" of weld. 4. Width of ISI > 1/8" 5. > 4 ISI with maximum width of 1/8" in any 12" of weld. 6. Sum of the lengths of ESI & ISI > 8% of weld length.
Porosity - individual / Scattered (P) Note: Size based on maximum dimensions
Unacceptable if: 1. Size of individual pore > 1/8" 2. Size of individual pore > 25% of thinner WT joined 3. Distribution of Porosity exceeds API STD 1104 Porosity Charts.
Porosity - Cluster (CP)
Unacceptable if: 1. CP dia. > ½" 2. Aggregate length of CP > ½" in any continuous 12" of weld 3. An individual pore within a cluster > 1/16" in size.
Porosity - Hollow-Bead (HB)
Unacceptable if: 1. Length of individual HB > ½" 2. Sum of HB lengths > 2" in any continuous 12" of weld 3. Individual HB > ¼" separated by < 2" 4. Sum of HB lengths > 8% weld length.
Cracks (C)
Any size or location of cracks are unacceptable except for shallow crater or star cracks. Shallow crater or star crack length > 5/32" is unacceptable.
Undercutting Adjacent to cover pass (EU) Adjacent to root pass (IU)
Unacceptable if: 1. Any combination EU & IU length > 2" in any continuous 12" of weld. 2. Sum of EU & IU lengths in any combination > 1/6 of weld length.
Tungsten Inclusions
Individual tungsten inclusions are be evaluated as rounded indications (Porosity). Elongated or aligned tungsten inclusions are unacceptable.
Accumulation of Discontinuities Excluding IPD, EU & IU
Unacceptable if: 1. Sum lengths of indications > 2" in any continuous 12" of weld. 2. Sum lengths of indication > 8% of weld length.
Pipe / Fitting Discontinuities
Arc burns, long seam discontinuities and other discontinuities in the pipe or fittings detected by RT shall be recordable.
Pipe OD < 2-3/8" Unacceptable if: 1. ESI > 3 X nominal WT of the thinner thickness joined. 2. ESI width > 1/16" 3. Sum of ISI lengths > 2 X nominal WT of thinner thickness joined and ISI width > ½ nominal WT of thinner thickness joined. 4. Aggregate length of ESI & ISI > 8% of weld length.
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AWS D1.1 Radiographic acceptance criteria for AWS D1.1 is different for Statically Loaded and Dynamically Loaded structures. This SAEP covers only statically loaded structures. For Dynamically loaded structures, refer to the appropriate sections of AWS D1.1. If there is doubt as to the designation of statically or dynamically loaded, refer to the project engineer for determination. The radiographic film interpreter should confirm the loading classification prior to proceeding the interpretation of film. Rejection criteria for statically loaded structures are provided below. Note that to determine the allowable and rejectable size of discontinuities, the use of both the tables and charts are required. Statically Loaded Structures Table 4-1 (AWS D1.1 Paragraph 8.15.3.2) and figure 4-1 together establish the rejection criteria for radiographic indications of statically loaded structures. Discontinuities exceeding the following limitations shall be unacceptable. (E = weld size; T = material thickness) Table 4-1 – Rejection Criteria for Statically Loaded Structures, AWS D1.1 Para 8.15.3.2 Indication
Rejection Criteria
Cracks
None permitted
Elongated Discontinuities
> maximum size of chart 4-1
Clearance between discontinuities
< minimum clearance allowance of fig 4-1
Rounded Discontinuities
Isolated Discontinuity, i.e., a cluster of rounded indications Sum of Individual Discontinuities each being < 3/32" In-Line Discontinuities Tungsten Inclusions
> E/3 or > ¼" for T ≤ 2" > E/3 or > 3/8" for T > 2" Minimum clearance between a rounded discontinuity > 3/32" to an acceptable rounded or elongated discontinuity or to an edge or end of an intersection shall be three (3) times the larger discontinuity. Sum of greatest dimension > maximum size of a single discontinuity permitted in Fig. 4-1. Minimum clearance to another cluster or elongated discontinuity or to an edge or end of an intersecting shall be three (3) times the larger discontinuity. shall not exceed 2E/3 or 3/8" which ever is less in 1" of weld. Sum > E in any length of 6E. Where length of weld is < 6E, permissible sum shall be proportionately less. Individual tungsten inclusions are be evaluated as rounded indications (Porosity). Elongated or aligned tungsten inclusions are unacceptable.
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Figure 4-1 Weld Quality Requirements for Elongated Discontinuities as Determined by Radiography for Statically Loaded Structures (see AWS D1.1 Paragraph 6.15.3.2)
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Attachment 1 – Radiographic Request / Report Forms
Saudi Aramco Form 4719-A-ENG (09/98)
Saudi Aramco Form 4719-A1-ENG (09/98)
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