1. Aws D1.1 Ut Acceptance Criteria
2. Aws D1.1 Weld Acceptance Criteria
3. Aws D1.1 Visual Acceptance Criteria

Liquid penetrant testing acceptance criteria depend on theconstruction code. For example, if a pressure vessel such as a reactor, heatexchanger, drum, process tower subjected to the test, then acceptance criteriacan be found in the ASME Code SectionVIII Div. 1 Appendix 8. If you are doing a penetrant test on steel structure,then you should look for acceptance criteria in the AWS D1.1

Liquid Penetrant Testing Acceptance Criteria Based on ASMEVIII Div 1 Appendix 8

03:26 Feb-21-2017 AWS D1.1 - UT requirements X or XF acceptance criteria. I have a question for AWS D1.1 acceptance criteria. When we find an indication at scanning level using primary procedures selected from tab. 6.7, in case of discontinuity indication located at weld-base metal interface, the scanning requirements X or XF have to be applied.

AWS D1.1 Guide to Qualification of Welders and Welding Procedures. Step during performance qualifications. Specific instruction can be found in Section 4.9 – Methods of Testing and Acceptance Criteria for WPS Qualifications. Radiographic testing uses X-ray or gamma rays to project an image of the weldment onto a radiographic film. For process Piping: Acceptance criteria shall be based on ASME B 31.3 table 341.3.2 A for normal fluid service, with the exception of piping class E. For structural steel: acceptance criteria shall be in accordance with the requirement of AWS D1.1-98 section 6.12.1 for non-tubular structure and section 6.12.3 for tubular joints. AWS D1.8 and Other AWS Standards AWS D1.8 supplements AWS D1.1 Structural Welding Code—Steel 6. D1.8 does not replace D1.1, and except as modified by D1.8, all of D1.1 still applies when D1.8 is specified. See D1.8, clause 1.1. AWS D1.8 is intended to be used on steel structures, where D1.1 applies. D1.8 should not, for example.

The ASME Code Section VIII Div. 1 Mandatory Appendix 8covers the acceptance criteria for Penetrant testing on the weld. Please noteAPI codes for rotating equipment also refer to this code. For instance, if youare performing a liquid penetrant testing on pipe weld to pump casing and youfind an indication, then you need to refer to appendix 8 of the code mentioned above for evaluationsince the API 610 does not directly address the acceptance criteria issue.

As per appendix 8, any indication greater than 1/16 in (1.5mm) shall be considered a relevant indication. You may ignore any indicationthat might be less than this value. It divides the indication into two groupsas follows:

Rounded indications: any relevant indication (it means if itsmajor dimension is greater than 1/16 (1.5 mm) ) shall be considered rejected ifit is greater than 3/16 in (5 mm)

Linear or elongated indication: all elongated indication arerejected regardless of the size. An indication is elongated or linear when itslength is three times of its wide.

As you see, there is more leeway for rounded indication.However, if several rounded indications existed in line and separated by ashort distance, might be considered rejected indications.

Liquid Penetrant Testing Acceptance Criteria for ProcessPiping - ASME B31.3

The acceptance criteria exactly is as the same of ASMESection VIII Div. 1 Appendix 8. The criteria addressed in clause number 344.4.2- Acceptance Criteria

Liquid Penetrant Testing Acceptance Criteria for Casting Usedfor Pressure Vessels and Rotating Equipment

The ASME Code Section VIII Div. 1 Appendix 7 addresses thisissue. The code requires all cracks and hot tears to be rejectedregardless of the size. The rounded indication can be considered rejected ifthe size is greater than 3/16 inch or 5 mm.

The linear indication depends on the thickness if the thickness is lessthan 0.75 inch then any linear indication greater than 1/4 inch will beconsidered unacceptable. If the thickness of the test object is between 0.75and 2.25 inch, then max allowed linear indication is the 1/3 of the thickness.

An indication mightbe rejected based on one code or standard and might be acceptable based anothercode and standard.

The test evaluation and interpretation shall be done byqualified ASNT Level II or Level III liquid penetrant test technicians.

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This article provides you with a sample magnetic particle inspection / Testing procedure. This sample procedure covers AC electromagnetic yoke method. This procedure is a draft magnetic particle testing procedure and you need to modify it to meet your project specification.

1.0 MAGNETIC PARTICLE INSPECTION - SCOPE

1.1 Thisprocedure give the general requirements for carrying out the examination ofwelds in ferric materials using the AC electro magnetic yoke technique.

1.2 Thisprocedure meets the requirements of ASME Section V Article 7 and ASTM E-709-95.

2.0 MAGNETIC PARTICLE INSPECTION -DESCRIPTIONOF METHOD

2.1 Thismethod involves the magnetisation of an area to be examined and the applicationof ferromagnetic particles to the surface. The particles gather at areas of magnetic flux leakage and formindications characteristic of the type of discontinuity detected.

2.2 Maximum sensitivity is achieved when linear discontinuitiesare oriented perpendicular to the lines of flux.

2.3 The AC electromagnetic yoke technique isrestricted to the detection of surface breaking discontinuities.

3.0MAGNETIC PARTICLE INSPECTION - EAUIPMENTAND MATERIALS

3.1 This procedure is intended for use withthe following equipment and consumables or their equivalent.

• MagnafluxY6 AC Yoke
• Portableultra violet light
• MagnafluxWCP-1 White contrast paint
• MagnafluxWCP-2 White contrast paint
• Magnaflux7HE Black Ink
• MagnafluxSKC-NF cleaner
• MagnafluxSKC-S cleaner
• Magnafluxdry powder (red, yellow or grey colour)
• Magnaflux14 HF Fluorescent Ink
• Magnaflux20A Fluorescent Ink concentrate (water based)
• BurmahCastrol magnetic field indicators Type 1 Brass finish.

4.0MAGNETIC PARTICLE INSPECTION -PARTSTO BE EXAMINED

4.1 Welds in ferritic materials, whether in theas welded or dressed condition and the associated heat affected zones andparent material within at least one inch of the weld on both sides of the weld.

5.0 MAGNETIC PARTICLE INSPECTION -SURFACEPREPARATION

5.1 Prior to the test the area to beinspected and at least one inch either side shall be free from any features that may inhibit the test ormask unacceptable discontinuities. Theseinclude but are not limited to, slag, spatter, oil, scale, rough surface andprotective coatings.

5.2 Surface preparation by grinding,machining or other methods may be necessary where surface irregularities couldmask indications of unacceptable discontinuities.

5.3 The temperature of the test surface shallnot exceed 135ºFfor magnetic inks and 600ºF fordry powders. (For dry powders, testsurface be clean and dry).

5.4 For parts to be inspected using magneticinks the area to be inspected may, if necessary, be precleaned with a clothlightly moistened with cleaner.

5.5 Where parts are to be examined usingpowders or fluorescent inks, the surface finish as detailed in 5.1 to 5.4 isadequate.

5.6 When using black magnetic inks thesurface may be given contrast enhancement by applying a thin, even coating ofwhite contrast paint of a type as detailed in Section 3.1.

6.0 MAGNETIC PARTICLE INSPECTION - EQUIPMENT ANDCONSUMABLE CONTROL

6.1 The magnetising force of yokes shall bechecked at least once a year or after any damage and/or repair, Theyoke shall be able to lift a weight of at least 10 pounds at the maximum polespacing that will be used.

6.2 Magnetic powders shall be used on a onceonly, expendable basis. Care shall betaken to avoid possible contamination.

6.3 Magnetic inks are also once only,expendable materials and care shall be taken to thoroughly agitate the inkbefore use.

6.4 Magnetic inks mixed from concentratesshall be subject to a settlement test before use. Settlement time shall be 30 minutes andsettlement volume for the solids shall be as below.

• Fluorescent ink 0.1 - 0.4%
• Nonfluorescent ink 1.2 - 2.4%

6.5 The black light intensity at the examination surface(15 infrom the face of the light lens filter) shall be not be less than 1000 µW/cm2. Any increase in this value to suitclients specific requirements shall be detailed on the technique sheet. The bulb shall be allowed to warm up for atleast 5 minutes before use.

6.6 The black light intensity shallbe checked at least every 8 hours of use in accordance with 6.5 using acalibrated black light meter.

7.0 MAGNETIC PARTICLE INSPECTION - LIGHTING CONDITIONS

7.1 When conducting an examination underwhite lighting conditions, the inspector shall ensure that the level oflighting is adequate at the surface of the part (recommended minimum 100 footcandles or 1000 lux). 50 foot candles(500 lux) lighting may be used if agreed with customer, for field inspections.

7.2 Examinations under ultra violet lightingshould have a background white light level of less than 20 lux and an ultraviolet intensity at the test surface of not less than 1000µW/cm2. Any increase in these values shall bespecified in the technique sheet.

7.3 The inspector shall allow at least 5minutes for dark adaptation before beginning the inspection.

7.4 If the examiner wears glasses or lenses,they shall not be photosensitive.

8.0 MAGNETIC PARTICLE INSPECTION - DIRECTION OFMAGNETISING FIELD

8.1 The magnetising field shall be appliedsequentially in two directions approximately perpendicularto one another.

8.2 The direction of the field may bedetermined by using the Burmah Castrol magnetic field indicator. This will give its strongest indications whenplaced across the flux direction.

8.3 Determinationof field direction shall be carried out for each geometry of weld to be inspected.

9.0MAGNETIC PARTICLE INSPECTION -SEQUENCEOF OPERATIONS

9.1 Thesurface to be inspected shall be prepared as section 5.0.

9.2 Thecontinuous magnetisation technique is to be employed.

9.3 Ensure in all operations that the polefaces remain in maximum contact with the surface.

9.4 Position the poles as described in 8.0and turn on the magnetising field.

9.5 For the wet magnetic particle method,apply the ink onto the area under test and allow to flow over the surface suchas to allow maximum exposure of the magnetic particles to any flux leakagepresent, excess material may be GENTLY blown across the surface to aidinterpretation.

9.6 Dry magnetic powders should be applied insuch a manner that a light, uniform, dust like coating settles on the surfaceof the area under inspection. Excesspower may be GENTLY blown across the surface to aid interpretation and increaseexposure of magnetic particles to any flux leakage present.

9.7 Maintain the magnetising field for atleast two seconds after step 9.5 or 9.6 and inspect immediately.

9.8 Repeat the above sequence atapproximately 90º to the above.

9.9 Repeat the above steps to cover the complete weld area underinspection ensuring an overlap between inspected areas of at least 25% of thepole spacing.

9.10 The area to be inspected shall be limitedto a maximum distance of one fourth of the pole spacing on either side of linejoining the two legs.

9.11 Pole area to be inspected shall be limitedto a maximum distance of one fourth of the pole spacing on either side of linejoining the two legs.

9.12 Pole spacing shall be limited to a maximumvalue equal to or less than that used when conducing the lift test of thestandard weight but shall be not less than 3 inches.

10.0 MAGNETIC PARTICLE INSPECTION - EVALUATIONOF INDICATIONS

10.1 An indication may be the evidence of asurface imperfection. All indicationsneed not be relevant. Relevantindications are those caused by leakage flux. Relevant indications due tounacceptable mechanical discontinuities are to be noted, located and sized.

10.2 Anyindication which is believed to be non relevant shall be re-examined again. Only indications having majordimension of greater than one sixteenth of an inch shall be considered relevant.

10.3 Aliner indication is one having a length greater than its width. A rounded indication is shape witha length equal to or less than three times its width.

10.4 Unacceptableindications shall be removed by chipping or grinding and shall be re-tested if the repaired surface is free ofsharp notches are corners / grinding marks. When a defect appears to be fullyremoved the area can be repaired and re-examined by the same method. Repaired areashall be blended into the surrounding surface so as to avoid sharp notches,crevices or corners.

10.5 Ifrequired the repaired area shall also be re-examined by another suitable NDT method.

11.0 MAGNETIC PARTICLE INSPECTION - ACCEPTANCECRITERIA

The acceptance criteria givenhereunder for relevant indications for various codes shall be used in general. The inspector using this is cautioned thatCode requirements do change, and that in the case of conflict it shall bereferred (in writing) to the appointed NDT Level III or to the Divisional Manager (NDT).

11.1 ANSI/ASME B31.1, Power Piping

11.1.1 Evaluationof Indications

11.1.1.1 Mechanical discontinuities at the surfacewill be indicated by the retention of the examination medium. All indications are not necessarily defectssince certain metallurgical discontinuities and magnetic permeabilityvariations may also produce similar indications which are not relevant to thedetection of unacceptable discontinuities.

11.1.1.2 Any indications which are believed to benon relevant shall be re-examined to verify whether or not actual defects arepresent. Surface conditioning mayprecede the re-examination. Non relevantindications which would mask indications of defects are unacceptable.

11.1.1.3 Relevant indications are those which resultfrom unacceptable mechanical discontinuities. Linear indications are those indications in which the length is morethan three times the width. Roundedindications are indications which are circular or elliptical with the lengthless than three times the width.

11.1.1.4 An indication of a discontinuity may be larger than the discontinuity that causes it; however, thesize of the indication and not the size of the discontinuity is the basis of acceptance or rejection.

11.1.2AcceptanceStandards

Aws D1.1 Ut Acceptance Criteria

Thefollowing relevant indications are unacceptable:

11.1.2.1 Any cracks or linear indications.

11.1.2.2 Rounded indications with dimensions graterthan 3/16 in. (5.0 mm)

11.1.2.3 Four or more rounded indications in a lineseparated by 1/16 in. (2.0 mm) or less, edge to edge.

11.1.2.4 Ten or more rounded indications in any 6sq. in of surface with the major dimension of this area not to exceed 6 in (150mm) with the area taken in the most unfavourable location relative to theindications being evaluated.

11.2ASMEBoiler and Pressure Vessel Code, Sec. VIII Div. 1 Pressure Vessels

11.2.1 Evaluationof Indications

Indicationswill be revealed by retention of magnetic particles. All such indications are not necessarilyimperfections, however, since excessive surface roughness, magneticpermeability variations (such as at the edge of Heat Affected Zones), etc. mayproduce similar indications. Anindication is the evidence of a mechanical imperfection. Only indications whichhave any dimension greater than 1/16 in. shall be considered relevant.

11.2.2AcceptanceStandards

Allsurfaces to be examined shall be free of:

11.2.2.1 Relevant linear indications

11.2.2.2 Relevant rounded indications greater than3/16 in.

11.2.2.3 Four or more relevant rounded indicationsin a line separated by 1/16 in. or less, edge to edge.

Aws D1.1 Weld Acceptance Criteria

11.3AWS D1.1 Structural Welding Code - Steel

Inspections may be performed immediately after the completed welds have cooled to ambient temperature. Magnetic ParticleTesting on welds in ASTM steels A514 and A517 shall be performed no sooner than48 hours after completion of the weld.

Indicationsrevealed by Magnetic Particle Testing shall be evaluated as per applicablecategories as follows:

11.3.1 StaticallyLoaded Structures:

Acceptancecriteria shall be as per 8.15.5 (i.e. 8.15.1) of AWS D1.1 (1992 Edition)

11.3.2 DynamicallyLoaded Structures:

Acceptancecriteria shall be as per 9.25.2 of AWS D1.1 (1992 Edition).

11.3.3 TubularStructures:

Acceptancecriteria shall be as per 10.17.5 (i.e. 10.17.1) of AWS D1.1.

Aws D1.1 Visual Acceptance Criteria

11.4 API Standard 1104 Pipelines and Related Facilities

11.4.1 Classificationof Indication

Anyindication with a maximum dimension of 1/16 in. (1.59 mm) or less shall beclassified as non relevant. Any largerindication believed to be non relevant shall be regarded as relevant untilre-examined by magnetic particle or another non-destructive testing method todetermine whether or not an actual discontinuity exists. The surface may be ground or other wiseconditioned before re-examination. Afteran indication is determined to be non relevant, other non relevant indicationof the same type need not be re-examined.

Relevantindications are those caused by discontinuities. Linear indications are those in which thelength is more than three times the width. Rounded indications are those in which the length is three times thewidth or less.

11.4.2 AcceptanceStandards

Relevantindications shall be unacceptable when any of the following conditions exists:

a. Linear indications evaluated as cratercracks or star cracks exceed 5/32 inch(3.96 mm) in length.

b. Linear indications are evaluated ascracks other than crater cracks or star cracks.

c. Linear indications are evaluated as IFand exceed 1 inch (25.4 mm) in totallength in a continuous 12-inch (304.8 mm) length of weld or 8 percent of the weld length.

d. Roundedindications shall be evaluated as follows:

i) Individual or scatteredporosity (P) shall be unacceptable when anyof the following conditions exists:

• The size of an individual pore exceeds 1/8inch (3.17 mm).
• Thesize of an individual pore exceeds 25 percent of the thinner of the nominal wall thickness joined.
• Thedistribution of scattered porosity exceeds the concentration permittedby the porosity charts supplied by APIfor radiography testing.

ii) Clusterporosity (CP) that occurs in any pass except the finish pass shall comply with the criteria of(i). CP that occurs in the finish pass shall be unacceptablewhen any of the following conditionsexists:

• Thediameter of the cluster exceeds 1/2 inch (12.7 mm).
• The aggregate length of CP in any continuous12 inch (304.8 mm) lengthof weld exceeds 1/2 inch (12.7 mm).
• An individual pore within a cluster exceeds1/16 inch (1.59 mm) in size.

11.5 ANSI/ASMEB31.3, Chemical Plantand Petroleum Refinery Piping

11.5.1 Acceptance Criteria:

11.5.1.1 Any crack or linear indication isunacceptable.

12.0MAGNETIC PARTICLE INSPECTION - PERSONNELQUALIFICATION

12.1 Personnel performing examinations to thisprocedure shall be qualified and certified in accordance with the requirementsof ASNT document SNT-TC-1A (1992 edition) ,ISO 9712 ,PCN or Accepted levelequivalent.

12.2 Only individuals qualified to NDT Level IIor individuals qualified to NDT Level I and working under the supervision of anNDT Level II may perform the examinations in accordance with this procedure.

12.3 Evaluation of test results shall be by NDTLevel II only.

13.0MAGNETIC PARTICLE INSPECTION -POST CLEANING

13.1 The inspection area shall be cleaned afterinspection with solvent (unless otherwise specified) to remove any excessresidues from the inspection process.

14.0MAGNETIC PARTICLE INSPECTION - DEMAGNETISATION

14.1 Demagnetisation shall be carried out wherespecifically requested by the client. The method to be employed shall be subject to agreement with the client.

15.0 MAGNETIC PARTICLE INSPECTION - REPORTING

15.1 A report shall be prepared detailing theresults of the examination.

15.2 The report shall contain sufficientinformation to enable a full assessment of quality and to ensure that anynon-acceptable areas can be accurately located should repair be necessary.

15.3 Any datum’s used shall be unambiguous.

15.4 Any restrictions to test shall be noted.

15.5 A statement of acceptability against theacceptance standard should be made.

16.0MAGNETIC PARTICLE INSPECTION - REFERENCED DOCUMENTS

• ASMESECTION V ARTICLE 7;
• ASMESECTION VIII, Division I
• ANSI/ASMEB31.1
• ANSI/ASME B 31.1
• ANSI/AWSD1.1
• ASTM E 709
• API1104
• SNT-TC-1A of ASNT

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