ASTM_E_2775_-_11.pdf

Designation:E277511Standard Practice forGuided Wave Testing of Above Ground Steel PipeworkUsing Piezoelectric Effect Transduction1This standard is issued under the fixed designation E2775;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice provides a procedure for the use of guidedwave testing(GWT),also previously known as long rangeultrasonic testing(LRUT)or guided wave ultrasonic testing(GWUT).1.2 GWT utilizes ultrasonic guided waves,sent in the axialdirection of the pipe,to non-destructively test pipes for defectsor other features by detecting changes in the cross-sectionand/or stiffness of the pipe.1.3 GWT is a screening tool.The method does not providea direct measurement of wall thickness or the exact dimensionsof defects/defected area;an estimate of the defect severityhowever can be provided.1.4 This practice is intended for use with tubular carbonsteel or low-alloy steel products having Nominal Pipe size(NPS)2 to 48 corresponding to 60.3 to 1219.2 mm(2.375 to 48in.)outer diameter,and wall thickness between 3.81 and 25.4mm(0.15 and 1 in.).1.5 This practice covers GWT using piezoelectric transduc-tion technology.1.6 This practice only applies to GWT of basic pipeconfiguration.This includes pipes that are straight,constructedof a single pipe size and schedules,fully accessible at the testlocation,jointed by girth welds,supported by simple contactsupports and free of internal,or external coatings,or both;thepipe may be insulated or painted.1.7 This practice provides a general procedure for perform-ing the examination and identifying various aspects of particu-lar importance to ensure valid results,but actual interpretationof the data is excluded.1.8 This practice does not establish an acceptance criterion.Specific acceptance criteria shall be specified in the contractualagreement by the responsible system user or engineering entity.1.9 UnitsThe values stated in SI units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.10 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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E543 Specification for Agencies Performing NondestructiveTestingE1065 Practice for Evaluating Characteristics of UltrasonicSearch UnitsE1316 Terminology for Nondestructive ExaminationsE1324 Guide for Measuring Some Electronic Characteristicsof Ultrasonic Testing Instruments3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 circumferential extentthe length of a pipe feature inthe circumferential direction,usually given as a percentage ofthe pipe circumference.3.1.2 coherent noiseindications caused by real disconti-nuities causing a background noise,which exponentially de-cays with distance.3.1.3 Cross-Sectional Area Change(CSC)the CSC iscalculated assuming that a reflection is purely caused by achange in cross-section.It is given as a percentage of the totalcross-section.However it is commonly used to report therelative amplitude of any signal regardless of its source.3.1.4 Distance Amplitude Correction(DAC)curvea refer-ence curve plotted using reference reflections(for example,weld reflections)at different distances from the test position.1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.10 onSpecialized NDT Methods.Current edition approved July 15,2011.Published July 2011.DOI:10.1520/E2775-11.2For 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 website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 This curve corrects for attenuation and amplitude drops whenestimating the cross-section change from a reflection at acertain distance.3.1.5 Estimated Cross Sectional Loss(ECL)this is some-times used instead of Cross-Sectional Area Change,where thefeature is related to a defect.3.1.6 flexural wavewave propagation mode that producesbending motion in the pipe.3.1.7 Guided Wave(GW)stress waves whose characteris-tics are constrained by the system material,geometry andconfiguration in which the waves are propagating.3.1.8 Guided Wave Testing(GWT)non-destructive testmethod that utilizes guided waves.3.1.9 longitudinal wavewave propagation mode that pro-duces