Radiography Testing Procedure
1.0 Scope:
This procedure describes the method and techniques for radiographic examination of butt joints for pressure vessels, process piping and power piping using gamma radiation source (Ir-192).
2.0 Reference:
ASME Sec. V Art- 1,2 & 22 Nondestructive Examination
ASME Sec. VIII, Div. I & 2 Boilers and Pressure Vessel Code
ASME / ANSI B31.1 / B31.3
AWS D1.1
3.0 Surface Preparation:
Materials: Surfaces shall satisfy the requirements of the applicable materials specifications, or referencing code section with additional conditioning, if necessary, by any suitable process to a degree that the resulting radiographic image due to any surface irregularities do not mask or be confused with discontinuities.
Welds: 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 the resulting radiographic image due to any irregularities do not mask or be confused with the image of any discontinuity. The finished surface of all butt-welded joints may be flush with the base material or may have reasonably uniform crowns, with reinforcement not to exceed that specified in the referencing Code section.
4.0 PERSONNEL QUALIFICATION
All personnel involved in radiographic testing, interpretation and evaluation shall be qualified ASNT document SNT-TC-1A, 2020 edition.
The exposure device and related equipments used to achieve the above scope shall be carried out by a team of 2 personnel as a minimum, Radiographer Level-I & Level-II or Assistant and shall be trained by AERB.
5.0 Back Scatter Radiation
A lead symbol “B” with minimum dimensions of 1/2" (13 mm) in height and 1/16" (1.6 mm) in thickness shall be attached to the back of each film holder, during each exposure to determine if back scatter radiation is exposing the film.
6.0 System of Identification:
6.1 A system shall be used to produce permanent identification on the radiograph traceable to the contract, component, and weld or weld seam or part numbers as appropriate.
6.2 In addition, name and the date of radiograph shall be plainly and permanently included on the radiograph. In any case this information shall not obscure the area of interest.
7.0 STAGE AND Extent of Examination:
When the time of the examination is not specifically stated in the referenced code section or project specification, final radiography for acceptance of the weld/material shall be performed after final post weld heat treatment.
The extent of radiographic examination shall be as specified in the NDT requisition prepared as specified by the referencing Code section or customer requirement.
8.0 Equipment & Materials:
8.1 Radiation sources
Acceptable radiation sources for use with this procedure shall be
Iridium – 192 (Ir-192) (upto 50 Ci)
8.2 Film
8.2.1 Radiographs shall be made using industrial radiographic film.
8.2.2 The film manufacturer shall determine and provide the classification of relative speeds of films.
8.2.3 Film brands with manufacturer defined relative speed are permitted for use.
|
Speed of Film |
Agfa |
Fuji |
Kodak |
|
Medium speed |
D – 7 |
IX100 |
AA 400 |
|
Slow speed |
D - 4 |
IX 50 |
MX 125 |
8.3 Processing
8.3.1 Industrial Radiography film developing chemicals as supplied by the following suppliers shall be used for developing the exposed films.
Agfa Gevaert
Premier
Kodak
Photochem
9.0 Intensifying Screens:
Lead Intensifying screens shall only be used when performing radiographic examination. Lead intensifying screens shall be used in direct contact with the films for intensification. The minimum thickness of the front lead screens shall be 0.005" (0.13 mm) for Iridium-192.
10.0 Image Quality Indicator (IQI) Design:
10.0
10.1 IQIs used shall be either the hole type or the wire type. ASME standard hole type IQIs shall consist of those in Table - IA and for wire type in Table - IB
These shall be suitably selected based on thickness of job.
TABLE –IA
Hole – Type IQI Designation, Thickness and Hole Diameters
|
IQI Designation |
IQI Thickness in. |
1 T Hole Diameter in. |
2 T Hole Diameter in. |
4 T 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 -IB
Wire IQI Designation, Wire Diameter, and Wire Identity
|
Set A |
Set B |
||
WireDiameter, in. |
Wire Identity |
WireDiameter, in. |
Wire Identity |
|
0.0032 |
1 |
0.010 |
6 |
|
0.004 |
2 |
0.013 |
7 |
|
0.005 |
3 |
0.016 |
8 |
|
0.0063 |
4 |
0.020 |
9 |
|
0.008 |
5 |
0.025 |
10 |
|
0.010 |
6 |
0.032 |
11 |
|
Set C |
Set D |
||
WireDiameter, in. |
Wire Identity |
WireDiameter, in. |
Wire Identity |
|
0.032 |
11 |
0.100 |
16 |
|
0.040 |
12 |
0.126 |
17 |
|
0.050 |
13 |
0.160 |
18 |
|
0.063 |
14 |
0.200 |
19 |
|
0.080 |
15 |
0.250 |
20 |
|
0.100 |
16 |
0.320 |
21 |
11.0 Facilities for Viewing of Radiographs:
11.1 Viewing facility shall provide subdued back ground lighting of an intensity that will not cause troublesome reflections, shadows or glare on the radiograph.
11.2 Equipments used to view radiographs for interpretation shall provide a variable light source sufficient for the essential IQI hole or designated wire to be visible for the specified density range. The viewing condition shall be such that light from around the outer edge of the radiograph or coming through low density portions of the radiograph does not interfere with interpretation.
12.0 Calibration
12.1 Verification of Source Size
The equipment manufacturers or suppliers publications, such as technical manuals, decay curves or written statements documenting the actual or maximum source size or focal spot shall be acceptable as source size verification.
12.2 Image Quality Indicator
Calibration certificate from the manufacturer or supplier shall be acceptable as verification of dimensions of hole type and wire type IQI.
13.0 Examinations
13.1 Radiographic Techniques
1) Double Wall Single Image technique shall be used for pipe diameter greater than 70.0mm
2) Double Wall Double Image (elliptical) technique shall be used for pipe diameter from 38.1mm (1.5”) up to 70.0mm (3” <OD).
3) Double Wall Double Image (Superimposed) technique for pipe diameter less than 38.1mm. This technique may also be applied to pipe diameter up to 70.0mm where structural appendages restrict application of the elliptical technique or whenever OD/ID ratio is greater than 1.4
4) Single Wall Single Image Panoramic technique shall be used for pipe diameter greater than 500mm. This technique may also be applied to smaller pipe sizes where access is possible and geometric un-sharpness requirement is satisfied.
5) Single Wall Single Image technique shall be used for plate welds.
13.1.1 For Welds with outer diameter less than 3½" (89 mm)
The radiation beam may 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 2 exposures taken at 90 deg. to each other shall be made for each joint.
13.1.1.1 As an alternative, the weld may be radiographed with the radiation beam positioned so that the images of both walls are superimposed. When complete coverage is required, a minimum of 3 exposures taken at either 60 deg. or 120 deg. to each other shall be made for each joint.
13.1.1.2 Additional exposures shall be made if the required radiographic coverage cannot be obtained using the minimum number of exposures indicated in b) or 13.1.3.1 above.
14.0 selection of Radiation Energy
14.1 X - Radiation
14.1.1 For examination of welds X-radiation employing X-ray generating units shall be used, when required by referencing code or contract.
14.1.2 The radiographic techniques shall demonstrate that the required radiographic sensitivity has been obtained.
14.2 Gamma Radiation
14.2.1 Radioactive sources of Ir-192, Co-60 shall be used for radiography. The radiation energy employed for any radiographic technique shall achieve the density and IQI image requirements.
The maximum thickness for the use of radioactive isotopes is primarily dictated by exposure time. The minimum recommended thickness limitation can be reduced when the radiographic techniques used demonstrate that the required radiographic sensitivity has been obtained.
15.0 Direction of Radiation
The direction of the central beam of radiation shall be centered on the area of interest whenever practical.
16.0 Geometric Unsharpness
16.1 Geometric Un sharpness of the radiograph shall be determined in accordance with the formula given below
Ug = Fd/D
F = Source size: the maximum projected dimension of the radiation source in the
Plane perpendicular to the distance D from the weld or object being
radiographed.
d = Distance from source side of weld or object being radiographed to the film
D = Distance from source of radiation to weld or object being radiographed
D and d shall be measured to the approximate centre of the area of interest.
16.2 Geometric Unsharpness of the radiograph shall not exceed the following limits.
|
Material Thickness |
Ug Maximum |
|
Under 2” (50.8 mm) |
0.020" (0.51 mm) |
|
2" through 3” (50.8–76.2 mm) |
0.030" (0.76 mm) |
|
Over 3" through 4” (76.2 –101.6 mm) |
0.040" (1.02 mm) |
|
Greater than 4” (101.6 mm) |
0.070" (1.78 mm) |
Material thickness is the thickness on which the IQI is based.
17.0 Exposure Time:
The exposure time is calculated based by the recommendation of film manufacturer.
18.0 Location Markers:
Location markers which are to appear as radiographic images on the film shall be placed on the part adjacent to the weld. Their location shall be permanently marked on the surface of the part being radiographed, when permitted or on a map in a manner permitting the area of interest on a radiograph to be accurately traceable to its location on the part, for the required retention period of the radiograph.
Evidence shall also be provided on the radiograph that the required coverage of the region being examined has been obtained. Location markers shall be placed as follows
18.1 Single Wall Viewing
a) Source Side Markers: Location markers shall be placed on the source side when radiographing the following
· Flat components or longitudinal joints in cylindrical or conical components.
· Curved or spherical components whose concave side is toward the source and when the source to material distance is less than the inside radius of the component.
· Curved or spherical component whose convex side is towards the source.
b) Film Side Markers: Location marker shall be placed on the film side when radiographing either curved or spherical components whose concave side is toward the source and when the “source to material” distance is greater than the inside radius.
c) Either Side Markers: Location markers may be placed on either source side or film side when radiographing either curved or spherical components whose concave side is toward the source and “source to material” distance equals the inside radius of the component. eg. Panoramic exposures for welds in drums, vessels and pipes.
18.2 Double Wall Viewing:
For double wall viewing, atleast one location marker shall be placed adjacent to the weld (or on the material in the area of interest) for each radiograph.
Mapping the placement of location markers when inaccessibility or other limitations prevent the placement of markers as stipulated above, a dimensional map of the marker placement shall accompany the radiographs to show that full coverage has been obtained.
19.0 IQI SelectioN
19.1 Material
IQIs shall be selected from either the same alloy material group or grade as identified in SE 1025 or from an alloy material groups or grade with less radiation absorption than the material being radiographed. For radiography of steel IQIs made of carbon steel or 300 series stainless steel shall be used.
19.2 Size
The designated hole IQI or essential wire shall be as specified in Table - II. A thinner or thicker hole type substituted for any section thickness listed in Table - II, provided an Equivalent IQI Sensitivity is maintained.
TABLE – II IQI Selection
|
Nominal Single-Wall Material Thickness Range
|
IQI |
||||
|
Source Side |
Film Side |
||||
|
Hole-Type Designation |
Wire-Type Essential Wire |
Hole-Type Designation |
Wire-Type Essential Wire |
||
|
in. |
mm |
|
|
|
|
|
Up to 0.25, incl. |
Up to 6.4, incl. |
12 |
5 |
10 |
4 |
|
Over 0.25 through 0.375 |
Over 6.4 through 9.5 |
15 |
6 |
12 |
5 |
|
Over 0.375 through 0.50 |
Over 9.5 through 12.7 |
17 |
7 |
15 |
6 |
|
Over 0.50 through 0.75 |
Over 12.7 through 19.0 |
20 |
8 |
17 |
7 |
|
Over 0.75 through 1.00 |
Over 19.0 through 25.4 |
25 |
9 |
20 |
8 |
|
Over 1.00 through 1.50 |
Over 25.4 through 38.1 |
30 |
10 |
25 |
9 |
|
Over 1.50 through 2.00 |
Over 38.1through 50.8 |
35 |
11 |
30 |
10 |
|
Over 2.00 through 2.50 |
Over 50.8through 63.5 |
40 |
12 |
35 |
11 |
|
Over 2.50 through 4.00 |
Over 63.5 through 101.6 |
50 |
13 |
40 |
12 |
|
Over 4.00 through 6.00 |
Over 101.6 through 152.4 |
60 |
14 |
50 |
13 |
|
Over 6.00 through 8.00 |
Over 152.4 through 203.2 |
80 |
16 |
60 |
14 |
|
Over 8.00 through 10.00 |
Over 203.2 through 254.0 |
100 |
17 |
80 |
16 |
|
Over 10.00 through 12.00 |
Over 254.0 through 304.8 |
120 |
18 |
100 |
17 |
|
Over 12.00 through 16.00 |
Over 304.8 through 406.4 |
160 |
20 |
120 |
18 |
|
Over 16.00 through 20.00 |
Over 406.4 through 508.0 |
200 |
21 |
160 |
20 |
a) Weld with Reinforcement
The thickness on which the IQI is based is the nominal single wall thickness plus the estimated weld reinforcement not to exceed the maximum permitted by the referencing Code section. Backing rings or strips shall not be considered as part of the thickness in the IQI selection. The actual measurement of the weld reinforcement is not required.
b) Welds without Reinforcement:
The thickness on which the IQI is based is the nominal single wall thickness. Backing rings or strips that shall not be considered as part of the weld thickness in IQI selection.
19.3 Welds Joining Dissimilar Materials or Welds with Dissimilar Filler Metal:
When the weld metal is of an alloy group or grade that has a radiation attenuation that is differing from the base material the IQI material selection shall be based on the weld metal and be in accordance with 19.1. When the density limits in paragraph 21.2.1 can not be met with one IQI and the exceptional density area(s) is at the interface of the weld metal and the base metals, then the material selection for additional IQI shall be based on the base material and be in accordance with 19.1.
20.0 Use of IQIs to Monitor Radiographic Examination:
20.1 Placement of IQIs
a) Source Side IQI
The IQIs shall be placed on the source side of the part being examined except for the condition described in b). When due to part or weld configuration or size it is not feasible to place the IQI on the part or weld, the IQI may be placed on a separate block, called shim. Shims shall be made of the same or radiographically similar materials and may be used to facilitate IQI positioning. There is no restriction on the shim thickness, provided the IQI / area of interest density tolerance requirements of 21.2.2 are met.
The shim shall be placed as close as possible to the part being radiographed.
The shim dimension shall exceed the IQI dimensions such that the outline of at least three sides of the IQI images shall be visible on the radiograph.
b) Film Side IQI
Where inaccessibility prevents hand placing the IQI(s) on the source side, the IQIs shall be placed on the film side in contact with the part being examined. A lead letter ‘F’ shall be placed adjacent to or on the IQI(s) but shall not mask the essential hole where hole type IQIs are used.
c) IQI Location for Welds
Hole IQIs
The IQI(s) shall be placed adjacent to or on the weld. The identification number(s) and when used, the lead letter ‘F’ shall not be in the area of interest, except when geometric configuration makes it impractical.
Wire IQIs
The IQI(s) shall be placed on the weld so that the length of the wire is perpendicular to the length of the weld. The identification numbers and when used, the lead letter ‘F’ shall not be in the area of interest, except when geometric configuration makes it impractical.
d) IQI Location for Materials Other Than Welds
The IQI(s) with the IQI identification number(s) and when used, a lead letter ‘F’ may be placed in the area of interest.
20.2 Number of IQIs
When one or more film holders are used for an exposure, atleast one IQI image shall appear on each radiograph except as outlined in b).
a) Multiple IQIs
If the requirements of 21.2 are met by using more than one IQI, one shall be representative of the lightest area of interest and the other the darkest area of interest, the intervening densities on the radiograph shall be considered as having acceptable density.
b) Special Cases
(i) For cylindrical components where the source is placed on the axis of the components and one or more film holders are used for a single exposure, of a complete circumference atleast three IQIs shall be spaced approximately 120° apart. Where sections of longitudinal welds adjoining the circumferential welds are radiographed simultaneously with the circumferential weld, an additional IQI shall be placed on each longitudinal weld at the end of each section most remote from the junction with the circumferential weld being radiographed.
(ii) For cylindrical components where the source is placed on the axis of the components and four or more film holders are used for a single exposure of a section of the circumference atleast three IQI shall be used. One IQI shall be in the approximate center of the section and one at each end, where the section of the circumference exposed, exceeds 240°, the rules of (i) above apply. Additional film locations may be required to obtain necessary IQI spacing; otherwise atleast one IQI image shall appear on each radiograph.
(iii) For spherical components, where the source is located at the center of the components and one or more film holders are used for a single exposure of a complete circumference, atleast three IQIs shall be spaced approximately 120° apart. For other welds radiographed simultaneously, one additional IQI shall be placed on each other weld.
(iv) For segments of spherical components, where the source is located at the center of the components and four or more film holders are used for an exposure of a circumferential weld, atleast three IQIs shall be used. One IQI shall be in the approximate center and one at each end of the portion exposed, when 240° exceeds, the rules of (iii) above apply.
Additional film locations may be required to obtain necessary IQI spacing. For other welds radio graphed simultaneously one additional IQI shall be placed on each weld.
(v) In order to maintain the continuity of records involving subsequent exposures, all radiographs exhibiting IQIs which qualify the techniques permitted in accordance with a), b) (i), (ii), (iii) & (iv) above shall be retained. When an array of objects in a circle is radio graphed atleast one IQI shall show on each object image.
20.3 Shims Under Hole IQI
For welds with shims under hole type IQI, the radiographic density throughout the area of interest shall be no more than minus 15% from (lighter than) the radiographic density through the IQI.
21.0 Evaluation
21.1 Quality of Radiograph
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 of the object being radiographed. Such blemishes include, but are not limited to:
a) Fogging.
b) Processing defects such as streaks, water marks or chemical stains.
c) Scratches, finger marks, crimps, dirtiness, static marks, smudges or tears.
d) False indication due to defective screens.
21.2 Radiographic Density
21.2.1 Density Limitation
The transmitted film density through the radiographic image of the body of the appropriate hole IQI or adjacent to the designated wire of a wire IQI and the area of interest shall be 1.8 minimum for single film viewing for radiographs made with an X-ray source and 2.0 minimum for radiograph made with gamma ray source. For composite viewing of multiple film exposures, each film of the composite set shall have a minimum density of 1.3. The maximum density shall be 4.0 for either single or composite viewing. A tolerance of 0.05 in density is allowed for variations between densitometer readings.
21.2.2 Density Variation
a) General
If the density of the radiograph anywhere through the area of interest varies by more than minus 15% or plus 30% from the density through the body of the hole type IQI or adjacent to the designated wire of a wire IQI, within the minimum / maximum allowable density ranges specified in 21.2.1 then an additional IQI shall be used for each exceptional area or areas and the radiograph retaken. When calculating the allowable variation in density, the calculation may be rounded to the nearest 0.1 within the range specified in 21.2.1.
b) With Shims
When shims are used the plus 30% density restriction of a) above may be exceeded and the minimum density requirements of 21.2.1 do not apply for the IQI provided the required IQI sensitivity of 22.1 is achieved.
22.0 IQI SENSITIVITY
22.1 Required Sensitivity
Radiography shall be performed with a technique of sufficient sensitivity to display the hole IQI image and the 2T hole, or essential wire of a wire IQI. The radiographs shall also display the identifying numbers and letters. If the designated hole IQI image and 2T hole or essential wire do not show on any film in multiple film technique, but do show in composite film viewing, interpretation shall be permitted only by composite film viewing.
22.2 Equivalent Hole Type Sensitivity.
If a thinner or thicker hole type IQI than listed in Table – II was substituted, an Equivalent IQI Sensitivity as specified in Table – III shall have been maintained as well as all other requirements for radiography having been met.
|
Hole-type Designation 2T Hole |
Equivalent Hole-Type Designations |
|
|
1T Hole |
4T Hole |
|
|
10 |
15 |
5 |
|
12 |
17 |
7 |
|
15 |
20 |
10 |
|
17 |
25 |
12 |
|
20 |
30 |
15 |
|
25 |
35 |
17 |
|
30 |
40 |
20 |
|
35 |
50 |
25 |
|
40 |
60 |
30 |
|
50 |
70 |
35 |
|
60 |
80 |
40 |
|
80 |
120 |
60 |
|
100 |
140 |
70 |
|
120 |
160 |
80 |
|
160 |
240 |
120 |
|
200 |
280 |
140 |
23.0 Excessive Back Scatter
If the image of letter ‘B’ appears on the radiograph as a lighter image on a darker background, the protection from back scatter is insufficient and the radiograph shall be considered unacceptable. A dark image of the letter ‘B’ on a lighter background is not cause for rejection.
24.0 Interpretation:
24.1 Radiographs shall be examined and interpreted by authorized NDT personnel complying with procedure.
24.2 Defects that all exceeding the specification limit are to be repaired and re-radiographed and evaluated as per the original requirements.
25.0 Documentation:
Details of the radiographic examination such as technique, SFD, Screens, Number of Exposure, Sensitivity, Source, Density and IQI etc.,
26.0 Repair & Retest:
Any geometric imperfection that requires rework by surface conditioning (and not by welding) after initial radiography, the affected area shall be blended smooth with adjoining surfaces by grinding to avoid sharp notches, crevices or corners.
The blended area shall be re-radiographed with letters suffixed G1,G2, G3 etc., to the original identification number to denote the number of times the weld has undergone surface conditioning.
When radiographs are taken after repair by welding, letters R1, R2 etc., shall be suffixed to the original identification number, to denote the number of times the weld has undergone repair.
Wherever retake has been performed, letters RT 1, RT 2 shall be suffixed to the original identification number.
26.1 PROCESS CONTROL FAILURE:
If the testing process is found to be failed or not meeting the procedure requirements [e.g., Density, sensitivity or other necessary parameters]. It shall be informed to the customer and the product shall be recalled.
ACTION TAKEN:
The root cause for the process failure is analyzed and retest shall be performed
The process failure shall be informed to concerned responsible person and trained so that it does not recur
ACCEPTANCE CRITERIA
ASME/ANSI B31.1 for power piping and B31.3 for process piping.
|
Defect |
ASME SEC VIII D1, Para.
|
ASME SEC VIII D1, |
|
Crack |
None |
None |
|
Lack of Fusion |
None |
None |
|
Incomplete |
None |
None |
|
Elongated Indications |
6.0 mm (¼") for t up to 1/3t for t from 19.0 mm (¾") to 57.0 mm (2¼") inclusive; 19 mm (¾") for t over |
2/3 t where t is the thickness of the weld excluding allowed reinforcement |
|
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 |
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. |
|
Porosity & Rounded Indications |
Refer ASME SEC VIII D1, Appendix 4.
|
Round indications are not a factor unless 100% examination is required. |
|
Tungsten |
Refer to ASME SEC VIII D1, Appendix 4.
|
Rounded tungsten inclusions are to be evaluated as rounded indications per UW-51. Elongated and aligned tungsten inclusions are unacceptable. |
|
Root Concavity |
Unacceptable if the density is greater than that of the parent material. |
Unacceptable if the density is greater than that of the parent material. |
