1、Designation: E273 10Standard Practice forUltrasonic Testing of the Weld Zone of Welded Pipe andTubing1This standard is issued under the fixed designation E273; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This practice2describes general ultrasonic testi
3、ng pro-cedures for the detection of discontinuities in the weld andadjacent heat affected zones of welded pipe and tubing byscanning with relative motion between the search unit and pipeor tube. When contact or unfocused immersion search units areemployed, this practice is intended for tubular produ
4、cts havingspecified outside diameters $2 in. ($50 mm) and specifiedwall thicknesses of18 to 1116 in. (3 to 27 mm). When properlyfocused immersion search units are employed, this practicemay also be applied to material of smaller diameter and thinnerwall.NOTE 1When contact or unfocused immersion sear
5、ch units are used,precautions should be exercised when examining pipes or tubes near thelower specified limits. Certain combinations of search unit size, frequency,thinwall thicknesses, and small diameters could cause generation ofunwanted sound waves that may produce erroneous examination results.1
6、.2 All surfaces of material to be examined in accordancewith this practice shall be clean from scale, dirt, burrs, slag,spatter or other conditions that would interfere with theexamination results. The configuration of the weld must besuch that interfering signals are not generated by reflectionsfro
7、m it. Treatment of the inner surface and outer surface weldbeads such as trimming (“scarfing”) or rolling is often requiredto remove protuberances that could result in spurious reflec-tions.1.3 This practice does not establish acceptance criteria, theymust be specified by the using parties.1.4 The v
8、alues stated in inch-pound units are to be regardedas the standard. The SI equivalents are in parentheses and maybe approximate.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish
9、appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E543 Specification for Agencies Performing Nondestruc-tive TestingE1316 Terminology for Nondestructive Examinations2.2 ASNT DocumentsRecommended
10、 Practice SNT-TC-1A Personnel Qualifica-tion and Certification in Nondestructive Testing3. Terminology3.1 DefinitionsFor definitions of terms used in this prac-tice, see Terminology E1316.4. Summary of Practice4.1 A pulsed ultrasonic angle beam shall be propagated inthe wall of the pipe or tube by e
11、ither the surface contact orimmersion method. Fig. 1 illustrates the characteristic obliquesound entry into the pipe wall for both contact and immersionexamination from one search unit.NOTE 2The immersion examination method may include tanks,wheel search units, or bubbler systems.4.2 The weld line s
12、hall be examined from both sides toensure detection of imperfections with a shape or orientationthat produces a preferential direction of reflection.5. Apparatus5.1 The instruments and accessory equipment shall becapable of producing, receiving, amplifying, and displayingelectrical pulses at frequen
13、cies and pulse rates deemed neces-sary by the using parties. They shall be capable of distinguish-ing the reference reflectors described in Section 8 to the extentrequired in the standardization procedure outlined in Section 9.1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-s
14、tructive Testing and is the direct responsibility of Subcommittee E07.06 onUltrasonic Method.Current edition approved June 1, 2010. Published July 2010. Originally approvedin 1965. Last previous edition approved in 2005 as E273 - 01(2005). DOI:10.1520/E0273-10.2For ASME Boiler and Pressure Vessel Co
15、de applications see related PracticeSE-273 in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM
16、 website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 For pulse echo examination systems, the contact orimmersion search units should produce ultrasonic waves thattravel in the pipe or tube wall at a refracted angle of from 35
17、to 70 and perpendicular to the weld seam. For pitch/catch orthrough transmission examination systems, orientation of theentry sound beam other than perpendicular to the weld seammay be required.5.3 CouplantA liquid such as water, oil, glycerin, etc.,capable of conducting ultrasonic vibrations from t
18、he searchunit to the pipe or tube shall be used. Rust inhibitors, softeners,and wetting agents may be added to the couplant. The couplantliquid with all additives should not be detrimental to thesurface condition of the pipe or tubing and should wet thesurface. In examining electric-resistance-welde
19、d pipe, water-soluble oil used in cooling the pipe serves as a satisfactorycouplant.5.4 Distance Amplitude CompensationThe use of elec-tronic methods to compensate for attenuation losses as afunction of ultrasonic metal travel distance may be employed.5.5 Search UnitsThe search unit must be appropri
20、atelysized with respect to width and beam included angle to achievefull wall thickness coverage (2). Where this can not beachieved with a single search unit propagating in a givendirection, two or more search units may be used to scan in eachdirection. The effective beam length of the search units s
21、hall besuch that reliable detection of all reference reflectors isaccomplished without exceeding the “noise” limits of 9.2. Thefocal length of focused search units shall be at least equal to theradius of the material plus a suitable water path so that initialfocus may be on the tube or pipe central
22、axis (1).6. Basis of Application6.1 The following are items that require decision for use ofthis practice:6.1.1 Acceptance criteria,6.1.2 Type, dimension, and number of reference reflectors tobe placed in the reference standard,6.1.3 Standardization of examination sensitivity intervals,6.1.4 Operato
23、r qualifications,6.1.5 Qualification of NDT agency (as defined in PracticeE543), if required. Practice E543 may be used for this agencyqualification.6.1.6 Examination frequency,6.1.7 Pulse repetition rate,6.1.8 Sound beam orientation and number of beams used,6.1.9 Procedure and use of distance ampli
24、tude compensa-tion, and6.1.10 Reporting of examination results.7. Personnel Qualification7.1 Personnel performing the ultrasonic examination shallbe qualified and certified in accordance with ASNT Recom-mended Practice SNT-TC-1A or an equivalent document, toestablish their ability to conduct ultraso
25、nic weld examinations.8. Reference Standards8.1 A reference standard, of sufficient length to allowverification of system standardization, shall be prepared from alength of pipe or tubing of the same nominal diameter and wallthickness, material, surface finish, and acoustical properties asthe materi
26、al to be examined. The pipe or tube selected for thispurpose shall be free of discontinuities or other abnormalconditions that can cause interference with the detection of thereference reflectors. The reference reflectors shall be selectedto ensure uniform coverage of the weld at the sensitivity lev
27、elsprescribed. The reference reflectors most commonly used willconsist of machined notches and drilled holes as described inparagraph 8.2. All upset metal, burrs, etc., adjacent to thereference reflectors, shall be removed.8.1.1 Electric Resistance-Welded, Laser-Welded or Butt-Welded PipeReference r
28、eflectors shall be placed in the centerof weld seam and in a line parallel to it unless permission isobtained from the contracting or using agency to place thereference reflectors elsewhere in the reference standard. Whenlongitudinal notches are used as reference reflectors, they shallbe placed on t
29、he outer and inner surfaces of the referencestandard and be separated by a sufficient distance to ensure thatthe response from one reflector does not interfere with thatfrom the other.NOTE 3If reference reflectors are placed in a location other than thecenterline of the weld seam there is no assuran
30、ce that the beam ispenetrating the weld unless adequate signal response is obtained from thesearch units scanning the reflector from both sides of the weld. The loweramplitude of response from the two directions must be used in determin-ing the rejection threshold level. Positioning of automatic ala
31、rm gatesmust be such as to respond to the signal from the reference reflector, butalso the signals originating from the reflections from discontinuitiesanywhere in the weld seam itself.8.1.2 Fusion-Welded PipeThe reference reflectors shallbe placed in the weld. When longitudinal notches are used asN
32、OTE 1u = 35 through 70.FIG. 1 Angle Projection of Ultrasonic WaveE273 102reference reflectors, they shall be placed in the crown of thefusion-weld bead as shown in Fig. 2(a). In fusion-welded pipecontaining both inside and outside surface weld beads, alongitudinal notch reference reflector shall be
33、placed in theweld-bead crown on both the outside and inside surfaces.8.1.2.1 When drilled holes are employed, they shall bedrilled radially from both the outside and inside surfacesthrough 50 % of the wall thickness at the weld-bead crown orsuch other depth as agreed upon by the user or contractinga
34、gency and separated by some distance that guarantees adistinct and separate response from each one (see Fig. 2(c) andFig. 2(d). By agreement between the purchaser and manufac-turer, a hole drilled radially 100 % through the pipe wall maybe used instead of the 50 % drilled hole (see Fig. 2(e).NOTE 4F
35、ill 50 % deep or through-holes with a waterproof filler suchas bees wax to prevent couplant entry. Otherwise, such entry couldproduce erratic and/or spurious reflections.8.1.2.2 Additional reflectors may be used to produce signalsat reflection times that define weld-zone extremities for thepurpose o
36、f establishing alarm gate timing or other means ofcontrolling the examination area. Holes may be drilled radially100 % through the pipe wall at the weld-zone edges.8.2 The notch dimensions of length, depth, width, and forFig. 3(a) and Fig. 3(b) the included angle a shall be decidedupon by the using
37、party or parties. Fig. 3 illustrates thecommonly accepted notch configurations and the dimensionsto be measured.8.2.1 The notch depth (h) shall be measured from theadjacent surface to its maximum and minimum penetration.Measurements may be made by optical, replicating or me-chanical, or other techni
38、ques. Notch depth is commonlyspecified as a percent of nominal wall thickness with typicalvalues being 10, 1212 , or 20 %. A +0/-10 % tolerance isallowable on notch depths.8.2.2 The notch length (l) is considered to be the dimensionover which the specified depth is maintained.8.2.3 The width (w) of
39、the notch has negligible effect onstandardization and is not a critical dimension.9. Standardization of Examination Sensitivity9.1 Using the reference standard specified in 8.1, the equip-ment shall be adjusted to produce readily distinguished andclearly identifiable indications from both the inner
40、and outerreference reflectors. The relative response to the inner andouter reflectors shall be as near equal as possible. The lesser ofthe two responses shall be used as the acceptance level.NOTE 5Adjustment of water path, adjustment of distance (d)inFig.1 and angulation of the beam are used to achi
41、eve equality. It should benoted however, that detection, or balancing of signals from both outersurface and inner surface notches does not guarantee that examination forradical defects is being achieved throughout the full wall thickness. Toeffect such examination, especially in pipes and tubes with
42、 thicker walls,it is necessary that the beam refraction angle and search unit size (beamincluded angle for focused units) be selected to be compatible with theration of diameter-to-wall-thickness of the material as stated in 5.5 anddescribed in Reference (2).9.2 Instrument sensitivity and scanning s
43、ystem parameters,such as search unit positioning and scanning, speed, shall beadjusted to produce signal levels that are repeatable from allreference indicators within the limits described below. If a stripchart or similar recorder is used, the amplitude stability of alltarget indications shall be w
44、ithin 10 % of full scale height(FSH) for several successive scans of the reference standardunder conditions simulating those that will be used for theactual material examination. Peak “noise” signal amplitudesobserved during scanning over a length of the referencestandard equal to at least twice the
45、 distance between outersurface and inner surface notches, shall not exceed 40 % of theminimum amplitude of the signals from the reference indica-tors. If only an audible or other alarm device is used to indicateFIG. 2 Typical Notch Locations for Fusion Welded PipeFIG. 3 Common Reference ReflectorsE2
46、73 103the presence of rejectable indications, such devices shall beactuated reliably by all reference indicators for several succes-sive scans of the reference standard under conditions simulat-ing those that will be used for the actual material examination.9.3 When weld edge reflectors are used, th
47、e equipment shallbe adjusted to produce clearly identifiable responses from themthat are distinguishable from the reference reflectors used to setrejection limits when the reference standard is scanned in amanner simulating the production examination of the pipe ortubing.9.4 During the standardizati
48、on procedure, the extent ofvariation in the dimension (d) (that is, the amount of weld lineskew with respect to the search units) that can be toleratedwithout exceeding the stability limits of 9.2 shall be deter-mined and provisions made in the scanning system to ensurethat the positions of the sear
49、ch units relative to the weld line aremaintained within that limit.10. Examination Procedure10.1 Move the pipe or tubing past the search unit with theweld in a fixed position with respect to the search unit.Movement of the search unit with respect to a stationary pipeis satisfactory. During examination, maintain distance (d) andangle u in Fig. 1 and the water path for immersion examinationas determined during adjustment of the examination sensitivity.Depending upon the degree of crookedness of the material tobe examined, maintenance of these parameters may req
