ASTM E2775-16(2023)
(Practice)Standard Practice for Guided Wave Testing of Above Ground Steel Pipework Using Piezoelectric Effect Transduction
Standard Practice for Guided Wave Testing of Above Ground Steel Pipework Using Piezoelectric Effect Transduction
SIGNIFICANCE AND USE
5.1 The purpose of this practice is to outline a procedure for using GWT to locate areas in metal pipes in which wall loss has occurred due to corrosion or erosion.
5.2 GWT does not provide a direct measurement of wall thickness, but is sensitive to a combination of the CSC and circumferential extent and axial extent of any metal loss. Based on this information, a classification of the severity can be assigned.
5.3 The GWT method provides a screening tool to quickly identify any discontinuity along the pipe. Where a possible defect is found, follow-up inspection of suspected areas with ultrasonic testing or other NDT methods is normally required to obtain detailed thickness information, nature, and extent of damage.
5.4 GWT also provides some information on the axial length of a discontinuity, provided that the axial length is longer than roughly a quarter of the wavelength of the excitation signal.
5.5 The identification and severity assessment of any possible defects is qualitative only. An interpretation process to differentiate between relevant and non-relevant signals is necessary.
5.6 This practice only covers the application specified in the scope. The GWT method has the capability and can be used for applications where the pipe is insulated, buried, in road crossings, and where access is limited.
5.7 GWT shall be performed by qualified and certified personnel, as specified in the contract or purchase order. Qualifications shall include training specific to the use of the equipment employed, interpretation of the test results and guided wave technology.
5.8 A documented program that includes training, examination and experience for the GWT personnel certification shall be maintained by the supplying party.
SCOPE
1.1 This practice provides a procedure for the use of guided wave testing (GWT), also previously known as long range ultrasonic testing (LRUT) or guided wave ultrasonic testing (GWUT).
1.2 GWT utilizes ultrasonic guided waves, sent in the axial direction of the pipe, to non-destructively test pipes for defects or other features by detecting changes in the cross-section or stiffness of the pipe, or both.
1.3 GWT is a screening tool. The method does not provide a direct measurement of wall thickness or the exact dimensions of defects/defected area; an estimate of the defect severity however can be provided.
1.4 This practice is intended for use with tubular carbon steel or low-alloy steel products having Nominal Pipe size (NPS) 2 to 48 corresponding to 60.3 mm to 1219.2 mm (2.375 in. to 48 in.) outer diameter, and wall thickness between 3.81 mm and 25.4 mm (0.15 in. and 1 in.).
1.5 This practice covers GWT using piezoelectric transduction technology.
1.6 This practice only applies to GWT of basic pipe configuration. This includes pipes that are straight, constructed of a single pipe size and schedules, fully accessible at the test location, jointed by girth welds, supported by simple contact supports and free of internal, or external coatings, or both; the pipe may be insulated or painted.
1.7 This practice provides a general procedure for performing the examination and identifying various aspects of particular importance to ensure valid results, but actual interpretation of the data is excluded.
1.8 This practice does not establish an acceptance criterion. Specific acceptance criteria shall be specified in the contractual agreement by the responsible system user or engineering entity.
1.9 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.10 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and de...
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2775 − 16 (Reapproved 2023)
Standard Practice for
Guided Wave Testing of Above Ground Steel Pipework
Using Piezoelectric Effect Transduction
This standard is issued under the fixed designation E2775; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.9 Units—The values stated in SI units are to be regarded
as standard. The values given in parentheses are mathematical
1.1 This practice provides a procedure for the use of guided
conversions to SI units that are provided for information only
wave testing (GWT), also previously known as long range
and are not considered standard.
ultrasonic testing (LRUT) or guided wave ultrasonic testing
1.10 This standard does not purport to address all of the
(GWUT).
safety concerns, if any, associated with its use. It is the
1.2 GWT utilizes ultrasonic guided waves, sent in the axial
responsibility of the user of this standard to establish appro-
direction of the pipe, to non-destructively test pipes for defects
priate safety, health, and environmental practices and deter-
or other features by detecting changes in the cross-section or
mine the applicability of regulatory limitations prior to use.
stiffness of the pipe, or both.
1.11 This international standard was developed in accor-
1.3 GWT is a screening tool. The method does not provide
dance with internationally recognized principles on standard-
a direct measurement of wall thickness or the exact dimensions
ization established in the Decision on Principles for the
of defects/defected area; an estimate of the defect severity
Development of International Standards, Guides and Recom-
however can be provided.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.4 This practice is intended for use with tubular carbon
steel or low-alloy steel products having Nominal Pipe size
2. Referenced Documents
(NPS) 2 to 48 corresponding to 60.3 mm to 1219.2 mm
2.1 ASTM Standards:
(2.375 in. to 48 in.) outer diameter, and wall thickness between
3.81 mm and 25.4 mm (0.15 in. and 1 in.). E543 Specification for Agencies Performing Nondestructive
Testing
1.5 This practice covers GWT using piezoelectric transduc-
E1065 Practice for Evaluating Characteristics of Ultrasonic
tion technology.
Search Units
1.6 This practice only applies to GWT of basic pipe
E1316 Terminology for Nondestructive Examinations
configuration. This includes pipes that are straight, constructed
E1324 Guide for Measuring Some Electronic Characteristics
of a single pipe size and schedules, fully accessible at the test
of Ultrasonic Testing Instruments
location, jointed by girth welds, supported by simple contact
2.2 Equipment Manufacturer’s User’s Manual
supports and free of internal, or external coatings, or both; the
pipe may be insulated or painted. 3. Terminology
1.7 This practice provides a general procedure for perform-
3.1 Definitions of Terms Specific to This Standard:
ing the examination and identifying various aspects of particu- 3.1.1 circumferential extent—the length of a pipe feature in
lar importance to ensure valid results, but actual interpretation
the circumferential direction, usually given as a percentage of
of the data is excluded. the pipe circumference.
1.8 This practice does not establish an acceptance criterion. 3.1.2 coherent noise—indications caused by real disconti-
nuities causing a background noise, which exponentially de-
Specific acceptance criteria shall be specified in the contractual
agreement by the responsible system user or engineering entity. cays with distance.
3.1.3 Cross-Sectional Area Change (CSC)—the CSC is
calculated assuming that a reflection is purely caused by a
This practice is under the jurisdiction of ASTM Committee E07 on Nonde-
structive Testing and is the direct responsibility of Subcommittee E07.10 on
Specialized NDT Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Dec. 1, 2023. Published January 2024. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2011. last previous edition approved in 2016 as E2775 – 16. Standards volume information, refer to the standard’s Document Summary page on
DOI:10.1520/E2775-16R23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2775 − 16 (2023)
FIG. 1 Typical GWT Results Collected in Normal Environment (Top) and in High Ambient Noise Environment (Bottom). (Both results are
displayed in the logarithmic amplitude scale.)
change in cross-section. It is given as a percentage of the total 3.1.10 incoherent noise—random indications caused by
cross-section. However it is commonly used to report the electrical and ambient signal pollution, giving rise to a constant
relative amplitude of any signal regardless of its source. average noise floor. The terms “ambient noise” and “random
noise” are also used.
3.1.4 Distance Amplitude Correction (DAC) curve—a refer-
ence curve plotted using reference reflections (for example, 3.1.11 pipe feature—pipe components including but not
weld reflections) at different distances from the test position. limited to weld, support, flange, bend and flaw (defect) cause
This curve corrects for attenuation and amplitude drops when reflections of a guided wave due to a change in geometry.
estimating the cross-section change from a reflection at a
3.1.12 reflection amplitude—the amplitude of the reflection
certain distance.
signal typically reported as CSC.
3.1.5 Estimated Cross-Sectional Loss (ECL)—this is some-
3.1.13 reflector orientation—the circumferential position of
times used instead of cross-sectional area change, where the
the feature on the pipe. This is reported as the clock position or
feature is related to a flaw.
degrees with regards to the orientation of the transducer ring.
3.1.6 flexural wave—wave propagation mode that produces
3.1.14 Signal-to-Noise-Ratio (SNR)—Ratio of the amplitude
bending motion in the pipe.
of any signal of interest to the amplitude of the average
3.1.7 Guided Wave (GW)—stress waves whose characteris- background noise, which includes both coherent and non-
tics are constrained by the system material, geometry and coherent types of noise as defined in Fig. 1.
configuration in which the waves are propagating.
3.1.15 torsional wave—wave propagation mode that pro-
3.1.8 Guided Wave Testing (GWT)—non-destructive test duces twisting motion in the pipe.
method that utilizes guided waves.
3.1.16 transducer ring—a ring array of transducers that is
3.1.9 longitudinal wave—wave propagation mode that pro- attached around the circumference of the pipe to generate GW.
duces compressional motion in the pipe. It is also commonly known as the ring.
E2775 − 16 (2023)
3.1.17 wave mode—a particular form of propagating wave defect is found, follow-up inspection of suspected areas with
motion generated into a pipe, such as flexural, torsional, or ultrasonic testing or other NDT methods is normally required
longitudinal. to obtain detailed thickness information, nature, and extent of
damage.
4. Summary of Practice
5.4 GWT also provides some information on the axial
4.1 GWT evaluates the condition of metal pipes to primarily
length of a discontinuity, provided that the axial length is
establish the severity classification of defects by applying GW
longer than roughly a quarter of the wavelength of the
at a typical test frequency of up to 150 kHz, which travels
excitation signal.
along the pipe. Reflections are generated by the change in
5.5 The identification and severity assessment of any pos-
cross-sectional area or stiffness of the pipe, or both.
sible defects is qualitative only. An interpretation process to
4.2 A transducer ring attached around the pipe screens the
differentiate between relevant and non-relevant signals is
pipe in both directions simultaneously. It can evaluate long
necessary.
lengths of pipe, and is especially useful when access to the pipe
5.6 This practice only covers the application specified in the
is limited.
scope. The GWT method has the capability and can be used for
4.3 This examination locates areas of thickness reduction(s)
applications where the pipe is insulated, buried, in road
and provides a severity classification as to the extent of that
crossings, and where access is limited.
damage. The results are used to assess the condition of the
5.7 GWT shall be performed by qualified and certified
pipe, to determine where damaged areas are located and their
personnel, as specified in the contract or purchase order.
circumferential position on the pipe. The information can be
Qualifications shall include training specific to the use of the
used to program and prioritize additional inspection work and
equipment employed, interpretation of the test results and
repairs.
guided wave technology.
4.4 Reflections produced by pipe features that are not
5.8 A documented program that includes training, examina-
associated with areas containing possible defects are consid-
tion and experience for the GWT personnel certification shall
ered as relevant signals. These features can be used for setting
be maintained by the supplying party.
GW system DAC levels and identifying the relative position
and distance of discontinuities and areas containing possible
6. Basis of Application
defects. Examples of these features are: circumferential welds,
elbows, welded supports, vents, drainage, insulation lugs, and
6.1 The following items are subject to contractual agree-
other welded attachments.
ment between the parties using or referencing this standard.
4.5 Other sources of reflection may include changes in
6.2 Personnel Qualifications—Unless otherwise specified in
surface impedance of the pipe. These reflections are normally
the contractual agreement, personnel performing examinations
not relevant, but should be analyzed and classified in an
to this practice shall be qualified in accordance with one of the
interpretation process. Examples of these changes are the
following:
presence of pipe supports and clamps. In the advanced
6.2.1 Personnel performing examinations to this standard
applications, which are not covered by this standard, these
shall be qualified in accordance with SNT-TC-1A and certified
changes may also include various types of external/internal
by the employer or certifying agency, as applicable. Other
coatings or entrance of the pipe to ground or concrete wall.
equivalent qualification documents may be used when speci-
fied in the contract or purchase order. The applicable revision
4.6 Inspection of the pipe section immediately connecting to
shall be the latest unless otherwise specified in the contractual
branch connections, bends or flanges are considered advance
agreement between parties.
applications which are not covered by this standard.
6.2.2 Personnel qualification accredited by the GWT manu-
4.7 False echoes are produced by phenomena such as
facturers.
reverberations, incomplete control of direction, distortion at
6.3 The practice or standard used and its applicable revision
elbows and others. These signals should be analyzed and
classified as false echoes in the interpretation process. shall be identified in the contractual agreement between the
using parties.
5. Significance and Use
6.4 Qualifications of Non-destructive Testing Agencies—
5.1 The purpose of this practice is to outline a procedure for
Unless otherwise specified in the contractual agreement, NDT
using GWT to locate areas in metal pipes in which wall loss
agencies shall be qualified and evaluated as described in
has occurred due to corrosion or erosion.
Specification E543, the applicable edition of Specification
5.2 GWT does not provide a direct measurement of wall E543 shall be specified in the contractual agreement.
thickness, but is sensitive to a combination of the CSC and
6.5 Procedure and Techniques—The procedures and tech-
circumferential extent and axial extent of any metal loss. Based
niques to be utilized shall be specified in the contractual
on this information, a classification of the severity can be
agreement. It should include the scope of the inspection, that is,
assigned.
the overall NDT examination intended to identify and estimate
5.3 The GWT method provides a screening tool to quickly the size of any indications detected by the examination, or
identify any discontinuity along the pipe. Where a possible simply locate and provide a relative severity classification.
E2775 − 16 (2023)
6.6 Surface Preparation—The pre-examination site prepa- 8. Examination Procedure
ration criteria shall be in accordance with 8.3 unless otherwise
8.1 It is important to ensure that the proposed inspection
specified.
falls within the capabilities of the technology and equipment
6.7 Required Interval of Examination—The required inter- and that the using party or parties understand the capabilities
val or the system time in service of the examination shall be and limitations as it applies to their inspection.
specified in the contractual agreement.
8.2 Pre-examination Preparation:
6.8 Extent of the Examination—The extent of the examina-
8.2.1 All test equipment shall have current and valid cali-
tion shall be in accordance with 6.5 above unless otherwise
bration certificates.
specified. The extent should include but is not limited to:
8.2.2 Follow the equipment manufacturer’s recommenda-
6.8.1 The sizes and length(s) of pipes to be inspected.
tions with regard to equipment pre-test verification and check
6.8.2 Limitations of the method in the areas of application.
list. As a minimum this check list should include but is not
limited to:
6.8.3 Drawings of pipe circuits, pipe nomenclature, and
identification of examination locations.
8.2.2.1 Electronics fully operational.
6.8.4 Pipe access method(s).
8.2.2.2 Proper charging of batteries.
6.8.5 Safety requirements.
8.2.2.3 Verification that interconnection cables are in good
condition and functioning correctly.
6.9 Reporting Criteria—The test results of the examination
8.2.2.4 Correct transducer ring size for the intended pipes.
shall be documented in accordance with the contractual agree-
ment. This may include requirements for permanent records of 8.2.2.5 Sufficient transducer module
...
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