ASME Section VIII div 2 2010. ASME Boiler and Pressure Vessel Code. Alternative Rules
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2010 SECTION VIII, DIVISION 2
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b) Joints welded with austenitic chromium-nickel steel filler metal or non-air-hardening nickel-chromium-
iron filler metal shall be given a radiographic or ultrasonic spot examination in accordance with the
methods described in paragraphs 7.5.3 and 7.5.4. For lined construction, at least one spot examination
shall include a portion of the liner weld that contacts weld metal in the base plate. One spot examination
shall be completed for every 15 m (50 ft) of weld.
7.4.8.2 Examination of Vessels and Parts
a) Vessels or parts of vessels constructed of clad or weld overlay base material shall have welded joints
examined using the radiographic or ultrasonic methods as required in paragraphs 7.4.1 through 7.4.7.
b) Examination of Base Plates Protected by a Strip Covering – If the base material weld in integral or weld
metal overlay clad or lined construction is protected by a covering strip or sheet of corrosion resistant
material applied over the weld in the base material to complete the cladding or lining, then any
radiographic or ultrasonic examination required by paragraphs 7.4.1 through 7.4.7 may be made on the
completed weld in the base plate before the covering is attached.
c) Examination of Base Plates Protected by an Alloy Weld – The radiographic or ultrasonic examination
required by paragraphs 7.4.1 through 7.4.7 shall be made after the joint, including the corrosion resistant
layer, is complete, except that the radiographic or ultrasonic examination may be made on the weld in
the base material before the alloy cover weld is deposited, provided the following requirements are met.
1) The thickness of the base material at the welded joint is not less than that required by the design
calculation.
2) The corrosion resistant alloy weld deposit is non-air-hardening.
3) The completed alloy weld deposit is examined by liquid penetrant examination in accordance with
paragraph 7.5.7.
7.4.8.3 Inspection and Tests
a) General Requirements - The rules in the following paragraphs apply specifically to the inspection and
testing of vessels that have clad or weld overlay corrosion resistant linings, and shall be used in
conjunction with the general requirements for inspection and testing in Parts 7 and 8, respectively.
b) Tightness of Applied Lining
1) A test for pressure tightness of the applied lining that will be appropriate for the intended service is
recommended, but the details of the test shall be as specified in the Users’ Design Specification.
NOTE: The test should be such as to assure freedom from damage to the load-carrying base
material.
2) Inspection of Vessel Interior after Test for Tightness – Following the hydrostatic pressure test the
interior of the vessel shall be visually examined to determine if there is any seepage of the test fluid
through the joints in the lining.
3) Requirements When Seepage Is Detected – In cases where seepage behind the applied liner is
detected, the vessel shall be heated slowly for a sufficient time to drive out all test fluid from behind
the applied liner without damage to the liner. After the test fluid is driven out, the lining shall be
repaired by welding. The Inspector shall determine if repetition of the radiography, the heat
treatment, or the hydrostatic test of the vessel after lining repairs is required to determine whether
the repair welds may have caused defects that penetrate into the base material.
7.4.9 Examination and Inspection of Tensile Property Enhanced Q and T Vessels
The following paragraphs are applicable only to vessels constructed of ferritic materials, listed in Table 3.A.2,
where the yield and ultimate tensile strength have been enhanced by quenching and tempering.
7.4.9.1 Type No.1 Welded Joint
100% examination per Table 7.3 is required. The examination shall be done after all corrosion resistant alloy
cover welding has been deposited.
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7.4.9.2 Nozzle Attachment Welds
Nozzle attachment welds as provided for in Table 4.2.13 shall be examined using the radiographic or
ultrasonic method in accordance with paragraphs 7.5.3 or 7.5.4 or 7.5.5 (see Table 7.2 and Table 7.3).
Nozzle attachment welds in shells over 50 mm (2 in) in thickness in accordance with Table 4.2.10 shall be
examined by the radiographic or ultrasonic methods in accordance with paragraphs 7.5.3 or 7.5.4, except that
for nozzles having an inside diameter of 50 mm (2 in) or less, the radiographic or ultrasonic examination may
be omitted. The required radiographic examination shall be made after all corrosion resistant alloy cover weld
has been deposited.
7.4.9.3 Weld Examination
a) Except as permitted in paragraph 7.4.9.3.b, all welds, including welds for attaching nonpressure parts to
quenched and tempered steel, shall be examined on all exposed surfaces, after pressure tests, by the
magnetic particle method in accordance with paragraph 7.5.6. A magnetization method shall be used
that will avoid arc strikes. Crack-like flaws are unacceptable and shall be removed or repaired. The
vessel shall be retested in accordance with Part 8 following the repair, and the welds re-examined. For
nozzle attachments shown in Table 4.2.10, Details 1, 2, and 8, the exposed cross section of the vessel
wall at the opening shall be included in the examination.
b) Alternative Use of Liquid Penetrant Method – As an acceptable alternative to magnetic particle
examination or when magnetic particle methods are not feasible because of the nonmagnetic character
of the weld deposits, a liquid penetrant method shall be used, see paragraph 7.5.7. For vessels
constructed of SA-333 Grade 8, SA-334 Grade 8, SA-353, SA-522, SA-553 Types I and II, and SA-645
Grade A material, the surface examination required in Table 7.2 shall be by the liquid penetrant method
either before or after the pressure test. Crack-like flaws are unacceptable and shall be removed or
repaired. The vessel shall be retested in accordance with Part 8 following the repair, and the repair
welds re-examined.
7.4.9.4 Examination of Corrosion Resistant Overlay Weld Metal
Corrosion resistant overlay weld metal shall be examined by a liquid penetrant method in accordance with
paragraph 7.5.7. Crack-like flaws are unacceptable and shall be removed or repaired.
7.4.10 Examination and Inspection of Integrally Forged Vessels
The rules of the following paragraphs apply specifically to the nondestructive examination of integrally forged
vessels.
7.4.10.1 Ultrasonic Examination
a) If the vessel is constructed of SA-372 Grade J, Class 110 material, the completed vessel after heat
treatment shall be examined ultrasonically in accordance with paragraphs 3.3.3 and 3.3.4. The
reference specimen shall have the same nominal thickness, composition, and heat treatment as the
vessel it represents. The angle beam examination shall be calibrated with a notch of a depth equal to
5% of the nominal section thickness, a length of approximately 25 mm (1 in), and a width not greater
than twice its depth.
b) If the vessel is constructed of SA-723 Class 1, Grades 1, 2, and 3, and SA-723 Class 2, Grades 1, 2, and
3 materials, then the completed vessel shall be examined in accordance with paragraph 3.3.4 regardless
of thickness.
c) A vessel is unacceptable if examination results show one or more discontinuities that produce indications
exceeding in amplitude the indication from the calibrated notch. Round bottom surface indications such
as pits, scores, and conditioned areas exceeding the amplitude of the calibrated notch shall be
acceptable if the thickness below the indication is not less than the design wall thickness of the vessel,
and its sides are faired to a ratio of not less than three to one.
7.4.10.2 Examination of Weld Repairs
a) For weld repairs of material containing 0.35% Carbon or less, all weld repairs shall be examined by
radiography, by a magnetic particle method, or by a liquid penetrant method, in accordance with the
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requirements of paragraphs 7.5.3, 7.5.6, or 7.5.7. Weld repairs shall be radiographed when the depth of
weld repair exceeds 10 mm (3/8 in) or one-half the material thickness whichever is less. The
acceptability of the repair welds shall be determined by the acceptance standards set forth in the
applicable paragraph.
b) For weld repairs of material containing more than 0.35% Carbon:
1) The examination of weld repairs in other than quenched and tempered materials shall meet the
requirements of paragraph 7.4.10.2.a, except that radiography shall be required when the depth of
weld repair exceeds 6 mm (1/4 in) or one-half the material thickness whichever is less.
2) Examination of weld repairs in material that is to be or has been liquid quenched and tempered shall
meet the requirements of paragraph 7.4.10.2.a, except that radiography shall be required
regardless of the depth of weld deposit.
7.4.10.3 Inspection of Test Specimens and Witnessing Tests
When test specimens are to be taken under the applicable material specifications, the Inspector at his option
may witness the selection, identifying stamping, and testing of these specimens. Tests and retests shall be
made in accordance with the requirements of the material specification.
7.4.11 Examination and Inspection of Fabricated Layered Vessels
7.4.11.1 The rules of the following paragraphs apply specifically to the nondestructive examination of
pressure vessels and vessel parts that are fabricated using layered construction. The examination
requirements for layered vessel construction are shown in Table 7.4. The rules of paragraphs 7.4.1 through
7.4.7 with Examination Group 1 or 2, whichever is applicable, shall apply for the non-layered parts that are
integral with the layered vessel.
7.4.11.2 Inner Shells and Inner Heads
Category A and B joints in the inner shells of layered shell sections and in the inner heads of layered heads
before application of the layers shall be examined throughout their entire length by the radiographic or
ultrasonic method in accordance with paragraphs 7.5.3 or 7.5.5 (see Table 7.3).
7.4.11.3 Layers – Welded Joints
a) Category A joints in layers 3 mm through 8 mm (1/8 in. through 5/16 in) in thickness welded to the
previous surface shall be examined for 100% of their length by the magnetic particle method in
accordance with paragraph 7.5.6.
b) Category A joints in layers over 8 mm through 16 mm (5/16 in. through 5/8 in) in thickness welded to the
previous surface shall be examined for 100% of their length by the magnetic particle method in
accordance with paragraph 7.5.6. In addition, these joints shall be examined for 10% of their length at
random using the ultrasonic method in accordance with paragraph 7.5.4, except that for the bottom 10%
of the weld thickness the distance amplitude correction curve or reference level may be raised by 6 dB.
The random spot examination shall be performed as specified in paragraph 7.4.11.10.
c) Category A joints in layers over 16 mm through 22 mm (5/8 in. through 7/8 in) in thickness welded to the
previous layer shall be examined for 100% of their length using the ultrasonic method in accordance with
paragraph 7.5.4, except that for the bottom 10% of the weld thickness the distance amplitude correction
curve or reference level may be raised by 6 dB.
d) Category A joints in layers not welded to the previous surface shall be examined before assembly for
100% of their length by radiographic or ultrasonic method in accordance with paragraph 7.5.3, 7.5.4 or
7.5.5 (see Table 7.3).
e) Welds in spirally wound strip construction with a winding (spiral angle) of 75° or less measured from the
vessel axial centerline shall be classified as Category A joints and examined accordingly.
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7.4.11.4 Layers – Step Welded Girth Joints
a) Category B joints in layers 3 mm through 8 mm (1/8 in. through 5/8 in) in thickness shall be examined for
10% of their length by the magnetic particle method (direct current only) in accordance with paragraph
7.5.6. The random spot examination shall be performed as specified in paragraph 7.4.11.10.
b) Category B joints in layers over 8 mm through 16 mm (5/16 in. through 5/8 in) in thickness shall be
examined for 100% of their length by the magnetic particle method (using direct current only) in
accordance with paragraph 7.5.6.
c) Category B joints in layers over 16 mm through 22 mm (5/8 in. through 7/8 in) in thickness shall be
examined for 100% of their length by the magnetic particle method (using direct current only) in
accordance with paragraph 7.5.6. In addition these joints shall be examined for 10% of their length by
the ultrasonic method in accordance with paragraph 7.5.4, except that for the bottom 10% of the weld
thickness the distance amplitude correction curve or reference level may be raised by 6 dB. The random
spot examination shall be performed as specified in paragraph 7.4.11.10.
d) Category B joints in layers over 22 mm (7/8 in) in thickness shall be examined for 100% of their length by
the ultrasonic method in accordance with paragraph 7.5.4, except that for the bottom 10% of the weld
thickness, the distance amplitude correction curve or reference level may be raised by 6 dB.
7.4.11.5 Butt Joints
a) Full thickness welding of solid sections to layered sections. Category A, B, and D joints attaching a solid
section to a layered section of any of the layered thicknesses given in paragraph 7.4.11.2 shall be
examined by the radiographic method for their entire length in accordance with paragraph 7.5.3.
b) It is recognized that layer wash or acceptable gaps (see paragraph 6.8.8.3) may show as indications
difficult to distinguish from slag on the radiograph. Layer wash is defined as the indications resulting
from slight weld penetration at the layer interfaces. Acceptance shall be based on reference to the weld
geometry as shown in Figure 7.1. As an alternative, an angle radiographic technique, as shown in
Figure 7.2, may be used to locate individual gaps in order to determine the acceptability of the indication.
Category A and B joints attaching a layered section to a layered section need not be radiographed after
being fully welded when the Category A hemispherical head and Category B welded joints of the inner
shell or inner head made after application of the layers have been radiographed in accordance with
paragraph 7.5.3.
c) The inner shell or inner head thicknesses need not be radiographed in thicknesses over 22 mm (0.875
in) if the completed joint is radiographed. Weld joints in the inner shell or inner head welded after
application of the layers of the inner shell or inner head weld joints shall be radiographed throughout their
entire length and meet the requirements of paragraph 7.4.11.2.
7.4.11.6 Flat Head and Tubesheet Weld Joints
Category C joints attaching layered shell, or layered heads to flat heads and tubesheets as shown in Figure
4.13.6, shall be examined to the same requirements as specified in paragraph 7.4.11.4 for Category B joints.
7.4.11.7 Nozzle and Communicating Chambers Weld Joints
Category D weld joints in layered shells or layered heads that do not require radiographic examination shall
be examined by the magnetic particle or liquid penetrant method in accordance with paragraph 7.5.6 or 7.5.7.
The partial penetration weld joining liner type nozzle to layer vessel shells or layer heads, as shown in Figure
4.13.9, shall be examined by magnetic particle or liquid penetrant in accordance with paragraph 7.5.6 or
7.5.7.
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7.4.11.8 Welds Attaching Nonpressure Parts and Stiffeners
a) All welds attaching supports, lugs, brackets, stiffeners, and other nonpressure attachments to pressure
parts shall be examined on all exposed surfaces by the magnetic particle or liquid penetrant method in
accordance with paragraph 7.5.6 or 7.5.7.
b) The examination required in paragraph 6.2.4.7 shall be made after postweld heat treatment for
nonpressure parts and stiffeners attached to Material Type 2 parts, see Table 4.2.3.
7.4.11.9 Transition Welds
a) All weld metal buildup in solid wall sections or fillet welds in layered transitions shall be examined over
the full surface of the deposit by either the magnetic particle or liquid penetrant method in accordance
with paragraph 7.5.6 or 7.5.7.
b) When such surface weld metal buildup is used in welded joints that require radiographic examination, the
weld metal buildup shall be included in the examination.
7.4.11.10 Random Spot Examination and Repair of Welds
The random ultrasonic examination of paragraph 7.4.11.3.b and paragraph 7.4.11.4.c, and random magnetic
particle examination of paragraph 7.4.11.4.a shall be performed as follows.
a) The location of the random spot shall be chosen by the Inspector, except that when the Inspector has
been duly notified in advance and cannot be present or otherwise make the selection, the fabricator may
exercise his own judgment in selecting the random spot or spots. The minimum length of a spot shall be
150 mm (6 in).
b) When any random spot examination discloses welding which does not comply with the minimum quality
requirements of paragraph 7.4.11.3.b and paragraphs 7.4.11.4.a and 7.4.11.4.c, two additional spots of
equal length shall be examined in the same weld unit at locations away from the original spot. The
locations of these additional spots shall be determined by the Inspector or fabricator as provided for in
the original spot examination.
c) If either of the two additional spots examined shows welding that does not comply with the minimum
quality requirements of paragraph 7.4.11.3.b and paragraphs 7.4.11.4.a and 7.4.11.4.c the entire unit of
weld represented shall be rejected. The entire rejected weld shall be removed and the joint shall be re-
welded or, at the fabricator's option, the entire unit of weld represented shall be completely examined
and defective welding only need be corrected.
d) Repair welding shall be performed using a qualified procedure and in a manner acceptable to the
Inspector. The re-welded joint or the weld repaired areas shall be random spot examined at one location
in accordance with the requirements of paragraph 7.4.11.3.b and paragraphs 7.4.11.4.a and 7.4.11.4.c.
7.5 Examination Method and Acceptance Criteria
7.5.1 General
Nondestructive Examination (NDE) techniques used in this Division and their associated acceptance criteria
are shown in Table 7.5.
7.5.2 Visual Examination
7.5.2.1 Examination Method
All welds for pressure retaining parts shall be visually examined. Personnel performing visual examinations
shall pass the annual eye test in accordance with paragraph 7.A.2.2.
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7.5.2.2 Acceptance Criteria
Welds that are observed to have indications exceeding the criteria given in Table 7.6 are unacceptable.
Unacceptable indications shall be removed or reduced to an indication of acceptable size. Whenever an
indication is removed by chipping or grinding and subsequent repair by welding is not required, the area shall
be blended into the surrounding surface so as to avoid notches, crevices, or corners. Where welding is
required after removal of indications, the repair shall be done in accordance with paragraph 6.2.7.
7.5.2.3 Examination of Hidden Weld Seams
Weld seams that will be hidden in the final vessel configuration shall be visually examined for workmanship
prior to final assembly, see paragraph 8.2.5.a.3.
7.5.3 Radiographic Examination
7.5.3.1 Examination Method
All welded joints to be radiographed shall be examined and documented in accordance with Article 2 of
Section V except as specified below.
a) A complete set of radiographs and records, as described in T-291 and T-292 of Article 2 of Section V, for
each vessel or vessel part shall be retained by the Manufacturer in accordance with paragraph 2.3.5.
b) Personnel performing and evaluating radiographic examinations required by this Division shall be
qualified and certified in accordance with paragraph 7.3.6.
c) Evaluation of radiographs shall only be performed by RT Level II or III personnel.
d) Demonstration of density and Image Quality Indicator (IQI) image requirements on production or
technique radiographs shall be considered satisfactory evidence of compliance with Article 2 of Section
V.
e) Final acceptance of radiographs shall be based on the ability to see the prescribed hole (IQI) image and
the specified hole or the designated wire of a wire IQI.
7.5.3.2 Acceptance Criteria
Indications shown on the radiographs of welds and characterized as defects are unacceptable under the
conditions listed in this paragraph and shall be repaired as provided in paragraph 6.2.7. Repaired welds shall
be re-examined, either by radiography in accordance with this paragraph or, at the option of the Manufacturer,
ultrasonically in accordance with paragraph 7.5.4 or 7.5.5 and the standards specified in this paragraph.
Should ultrasonic examination be performed, this examination method shall be noted under remarks on the
Manufacturer's Data Report Form.
a) Linear Indications
1) Terminology
Thickness
t – the thickness of the weld excluding any allowable reinforcement. For a butt weld
joining two members having different thicknesses at the weld,
t is the thinner of these two
thicknesses. If a full penetration weld includes a fillet weld, the thickness of the fillet throat shall be
included in the calculation of
t .
2) Acceptance/Rejection Criteria
i) Any crack or zone of incomplete fusion or lack of penetration
ii) Any other linear indication that has a length greater than:
1. 6 mm (1/4 in) for
t less than or equal to 19 mm (3/4 in),
2.
3t for t greater than 19 mm (3/4 in) and less than or equal to 57 mm (2 1/4 in),
3. 19 mm (3/4 in) for
t greater than 57 mm (2 1/4 in).
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iii) Any group of indications in line that has an aggregate length greater than
t in a length of
12t
,
except when the distance between the successive imperfections exceeds
6L , where L is the
length of the longest imperfection in the group;
iv) Internal root weld conditions are acceptable when the density or image brightness change as
indicated in the radiograph is not abrupt. Linear indications on the radiograph at either edge of
such conditions shall be evaluated in accordance with the other sections of this paragraph.
b) Rounded Indications
1) Terminology
i) Rounded Indications – indications with a maximum length of three times the width or less on
the radiograph are defined as rounded indications. These indications may be circular, elliptical,
conical, or irregular in shape and may have tails. When evaluating the size of an indication, the
tail shall be included.
ii) Aligned Indications – a sequence of four or more rounded indications shall be considered to be
aligned when they touch a line parallel to the length of the weld drawn through the center of the
two outer rounded indications.
iii) Thickness
t – the thickness of the weld, excluding any allowable reinforcement. For a butt
weld joining two members having different thicknesses at the weld,
t is the thinner of these
two thicknesses. If a full penetration weld includes a fillet weld, the thickness of the fillet throat
shall be included in the calculation of
t .
2) Acceptance Criteria
i) Rounded Indication Charts – relevant rounded indications characterized as imperfections shall
not exceed those shown in Figures 7.5 through 7.10, which illustrate various types of assorted,
randomly dispersed and clustered rounded indications for different weld thicknesses greater
than 3 mm (1/8 in). The charts for each thickness range represent full-scale 150 mm (6 in)
radiographs, and shall not be enlarged or reduced. The distributions shown are not
necessarily the patterns that may appear on the radiograph, but are typical of the concentration
and size of indications permitted.
ii) Relevant Indications (see Table 7.7 for examples) – only those rounded indications that exceed
the following dimensions shall be considered relevant and compared to the acceptance charts
for disposition.
1.
10t for t less than 3 mm (1/8 in)
2. 0.4 mm (1/64 in) for
t greater than or equal to 3 mm (1/8 in) and less than or equal to 6
mm (1/4 in)
3. 0.8 mm (1/32 in) for
t greater than 6 mm (1/4 in) and less than or equal to 50 mm (2 in)
4. 1.5 mm (1/16 in) for
t greater than 50 mm (2 in)
5. Maximum Size of Rounded Indication – the maximum permissible size of any indication
shall be
4t or 4 mm (5/32 in), whichever is smaller; except that an isolated indication
separated from an adjacent indication by 25 mm (1 in) or more may be
3t , or 6 mm (1/4
in), whichever is less. For
t greater than 50 mm (2 in) the maximum permissible size of
an isolated indication shall be increased to 10 mm (3/8 in).
6. Aligned Rounded Indications – aligned rounded indications are acceptable when the
summation of the diameters of the indications is less than
t in a length of 12t (see
Figure 7.3). The length of groups of aligned rounded indications and the spacing
between the groups shall meet the requirements of Figure 7.4.
7. Clustered Indications – the illustrations for clustered indications show up to four times as
many indications in a local area, as that shown in the illustrations for random indications.
The length of an acceptable cluster shall not exceed the lesser of 25 mm (1 in) or
2t .
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Where more than one cluster is present, the sum of the lengths of the clusters shall not
exceed 25 mm (1 in) in a 150 mm (6 in) length weld.
8. Weld Thickness
t less than 3 mm (1/8 in) – for t less than 3 mm (1/8 in) the maximum
number of rounded indications shall not exceed 12 in a 150 mm (6 in) length of weld. A
proportionally fewer number of indications shall be permitted in welds less than 150 mm
(6 in) in length.
iii) Image Density – density or image brightness within the image of the indication may vary and is
not a criterion for acceptance or rejection.
iv) Spacing – the distance between adjacent rounded indications is not a factor in determining
acceptance or rejection, except as required for isolated indications or groups of aligned
indications.
7.5.4 Ultrasonic Examination
7.5.4.1 All welded joints to be ultrasonically examined shall be examined and documented in accordance
with Article 4 of Section V except as specified below:
a) A complete set of records, as described in T-491 and T-492 of Article 4 of Section V, for each vessel or
vessel part shall be retained by the Manufacturer in accordance with paragraph 2.C.3. In addition, a
record of repaired areas shall be noted as well as the results of the reexamination of the repaired areas.
The Manufacturer shall also maintain a record from uncorrected areas having responses that exceed
50% of the reference level. This record shall locate each area, the response level, the dimensions, the
depth below the surface, and the classification.
b) Personnel performing and evaluating ultrasonic examinations required by this Division shall be qualified
and certified in accordance with paragraph 7.3.6
c) Flaw evaluations shall only be performed by UT Level II or III personnel.
d) Ultrasonic examination shall be performed in accordance with a written procedure certified by the
Manufacturer to be in accordance with the requirements of T-150 of Section V.
7.5.4.2 Acceptance Criteria
These standards shall apply unless other standards are specified for specific applications within this Division.
All imperfections that produce an amplitude greater than 20% of the reference level shall be investigated to
the extent that the operator can determine the shape, identity, and location of all such imperfections and
evaluate them in terms of the acceptance standards given in (a) and (b) below.
a) Imperfections that are interpreted to be cracks, lack of fusion, or incomplete penetration are
unacceptable regardless of length.
b) All other linear type imperfections are unacceptable if the amplitude exceeds the reference level and the
length of the imperfection exceeds the following:
1) 6 mm (1/4 in) for
t less than 19 mm (3/4 in)
2)
3t for t greater than or equal to 19 mm (3/4 in) and less than or equal to 57 mm (2-1/4 in)
3) 19 mm (3/4 in) for
t greater than 57 mm (2-1/4 in)
In the above criteria,
t is the thickness of the weld, excluding any allowable reinforcement (see
paragraph 6.2.4.1.d). For a butt weld joining two members having different thicknesses at the weld,
t is
the thinner of these two thicknesses. If a full penetration weld includes a fillet weld, the thickness of the
throat of the fillet shall be included in
t .
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7.5.5 Ultrasonic Examination Used in Lieu of Radiographic Examination
7.5.5.1 When used in lieu of the radiographic examination requirements of paragraph 7.5.3, ultrasonic
examination shall be performed in accordance with a written procedure conforming to the requirements of
Section V, Article 4, Mandatory Appendix VIII and the following additional requirements. For SAW welds in
2¼Cr-1Mo-V vessels, ultrasonic examination in accordance with this paragraph are required.
NOTE: For SAW welds in 2¼Cr-1Mo-V vessels, the potential exists for fabrication related cracking. Careful
selection of examination techniques, scans, calibrations, and acceptance criteria are necessary to provide the
sensitivity required to detect this cracking.
a) The ultrasonic examination area shall include the volume of the weld, plus 50 mm (2 in) on each side of
the weld for material thickness greater than 200 mm (8 in). For material thickness 200 mm (8 in) or less,
the ultrasonic examination area shall include the volume of the weld, plus the lesser of 25 mm (1 in) or
t
on each side of the weld. Alternatively, examination volume may be reduced to include the actual heat
affected zone (HAZ) plus 6 mm (1/4 in) of base material beyond the heat affected zone on each side of
the weld provided the following requirements are met:
1) The extent of the weld HAZ is measured and documented during the weld qualification process; and
2) The ultrasonic transducer positioning and scanning device is controlled using a reference mark
(paint or low stress stamp adjacent to the weld) to ensure that the actual HAZ plus an additional 6
mm (0.25 in) of base metal is examined.
b) The initial straight beam material examination (T-472 of Section V, Article 4) for reflectors that could
interfere with the angle beam examination shall be performed:
1) Manually,
2) As part of a previous manufacturing process, or
3) During the automatic UT examination provided detection of these reflectors is demonstrated.
c) Personnel performing and evaluating UT examinations shall be qualified and certified in accordance with
paragraph 7.3.6. Only UT Level II or III personnel shall analyze the data or interpret the results.
d) Contractor qualification records of certified personnel shall be approved by the Certificate Holder and
maintained by their employer.
e) In addition, personnel who acquire and analyze UT data shall participate in the qualification of the
procedure per Section V, Article 4 Mandatory Appendix IX.
f) The final data package shall be reviewed by a UT Level III individual. The review shall include:
1) The ultrasonic data record
2) Data interpretations
3) Flaw evaluations/characterizations performed by another qualified Level II or III individual. The data
review may be performed by another individual from the same organization. Alternatively, the
review may be achieved by arranging for a data acquisition and initial interpretation by a Level II
individual qualified in accordance with paragraphs 7.3.6 and Section V, Article 4 Mandatory
Appendix IX, and a final interpretation and evaluation shall be performed by a Level III individual
qualified similarly. The Level III individual shall have been qualified in accordance with paragraph
7.3.6 including a practical examination on flawed specimens.
g) Application of automated ultrasonic examinations shall be noted on the Manufacturer's Data Report, as
well as the extent of its use.
NOTE: Sectional scans (S-scans) with phased arrays may be used for the examination of welds, provided
they are qualified satisfactorily in accordance with paragraph 7.5.5.1.e. S-scans provide a fan beam from a
single emission point, which covers part or all of the weld, depending on transducer size, joint geometry, and
section thickness. While S-scans can demonstrate good detectability from side drilled holes, because they
2010 SECTION VIII, DIVISION 2
7-16
are omni-directional reflectors, the beams can be mis-oriented for planar reflectors (e.g., lack of fusion and
cracks.) This is particularly true for thicker sections, and it is recommended that multiple linear passes with S-
scans be utilized for components greater than 25mm (1 in.) thick. An adequate number of flaws should be
used in the demonstration block to ensure detectability for the entire weld volume.
7.5.5.2 Flaw Sizing
The dimensions of the flaw shall be determined by the rectangle that fully contains the area of the flaw (see
Figures 7.11 through 7.15).
a) The length (l) of the flaw shall be drawn parallel to the inside pressure-retaining surface of the
component.
b) The depth of the flaw shall be drawn normal to the inside pressure retaining surface and shall be
denoted as "a" for a surface flaw or "2a" for a subsurface flaw.
7.5.5.3 Flaw Evaluation and Acceptance Criteria
Flaws shall be evaluated for acceptance using the applicable criteria of Tables 7.8, 7.9 or 7.10, and with the
following additional requirements. Unacceptable flaws shall be repaired and the repaired welds shall be re-
evaluated for acceptance.
a) Surface Flaws – Flaws identified as surface flaws during the UT examination may or may not be surface
connected. Therefore, unless the UT data analysis confirms that the flaw is not surface connected, it
shall be considered surface connected or a flaw open to the surface, and is unacceptable unless surface
examination is performed. If the flaw is surface connected, the requirements above still apply. However,
in no case shall the flaw exceed the acceptance criteria in this Division for the material employed.
Acceptance surface examination techniques are as follows:
1) Magnetic particle examination (MT) in accordance with paragraph 7.5.6,
2) Liquid penetrant examination (PT) in accordance with paragraph 7.5.7,
3) Eddy Current examination (ET) in accordance with paragraph 7.5.8.
b) Multiple Flaws
1) Discontinuous flaws shall be considered a singular planar flaw if the distance between adjacent
flaws is equal to or less than the dimension S as shown in Figure 7.12.
2) Discontinuous flaws that are oriented primarily in parallel planes shall be considered a singular
planar flaw if the distance between the adjacent planes is equal to or less than 13 mm (1/2 in) (see
Figure 7.13).
3) Discontinuous flaws that are coplanar and nonaligned in the through-wall thickness direction of the
component shall be considered a singular planar flaw if the distance between adjacent flaws is
equal to or less than S as shown in Figure 7.14.
4) Discontinuous flaws that are coplanar in the through-wall direction within two parallel planes 13 mm
(1/2 in) apart (i.e., normal to the pressure-retaining surface of the component) are unacceptable if
the additive flaw depth dimension of the flaws exceeds those shown in Figure 7.15.
c) Subsurface Flaws – the flaw length (l) shall not exceed 4t.
7.5.6 Magnetic Particle Examination (MT)
7.5.6.1 All magnetic particle examinations shall be performed and documented in accordance with Article
7 of ASME Section V except as specified below:
a) A complete set of records, as described in T-791 and T-792 of Article 7 of Section V, for each vessel or
vessel part shall be retained by the Manufacturer until the Manufacturer’s Data Report has been signed
by the Inspector.
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