ASTM E3044/E3044M-22

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
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Designation: E3044/E3044M − 16 E3044/E3044M − 22
Standard Practice for
Ultrasonic Testing of Polyethylene Butt Fusion Joints
This standard is issued under the fixed designation E3044/E3044M; 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.
ε NOTE—Subsection 5.2 corrected editorially in September 2016.
1. Scope Scope*
1.1 This standard practice establishes procedures for ultrasonic testing (UT) of butt fusion joints in polyethylene pipe. Although
high density polyethylene (HDPE) and medium density polyethylene (MDPE) materials are most commonly used, the procedures
described may apply to other types of polyethylene.
NOTE 1—The notes in this specificationpractice are for information only and shall not be considered part of this specification.
NOTE 2—This standardpractice references HDPE and MDPE for pipe applications as defined by Specification D3350.
1.2 This standard practice does not address ultrasonic examination of electrofusion joints (coupling joints), socket joints, or
saddles.
1.3 This practice provides two ultrasonic examination procedures. Each has its own merits and requirements for examination and
shall be selected as agreed upon in a contractual document.
1.3.1 Examination Procedure A, Time of Flight Diffraction (TOFD), uses a pair of probes, one transmitting and the other receiving.
The procedure usually, although not necessarily, requires access to both sides of the joint from one surface. Provided that position
encoding is used, the procedure can be conducted by semi-automated or automated means that provide recoded imaging.
1.3.2 Examination Procedure B, Phased Array Ultrasonic Testing (PAUT), uses low velocity refracting wedges or water gaps to
produce angled compression mode pulses. The procedure can be applied where access is limited to one side of the joint from one
surface. Provided that position encoding is used, the procedure can be conducted by semi-automated or automated means that
provide recoded imaging.
1.4 The practice is intended to be used on thicknesses of 9 to 60 mm (0.375[0.375 to 2.4 in.)in.] and diameters 100 mm (4 in.)[4
in.] and greater. Greater and lesser thicknesses and lesser diameters may be tested using this standard practice if the technique can
be demonstrated to provide adequate detection on mockups of the same wall thickness and geometry.
1.5 This practice does not specify acceptance criteria.
1.6 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in
This practice is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.06 on Ultrasonic Method.
Current edition approved Aug. 1, 2016Feb. 1, 2022. Published August 2016February 2022. Originally approved in 2016. Last previous edition approved in 2016 as
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E3044/E3044M – 16 . DOI: 10.1520/E3044_E3044M-16.10.1520/E3044_E3044M-22.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3044/E3044M − 22
each system mayare not benecessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be
used independently of the other. Combiningother, and values from the two systems may result in non-conformance with the
standard.shall not be combined.
1.7 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.8 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.
2. Referenced Documents
2.1 The following documents form a part of this practice to the extent specified herein.
2.2 ASTM Standards:
D3350 Specification for Polyethylene Plastics Pipe and Fittings Materials
E494 Practice for Measuring Ultrasonic Velocity in Materials by Comparative Pulse-Echo Method
E543 Specification for Agencies Performing Nondestructive Testing
E1316 Terminology for Nondestructive Examinations
E2373 Practice for Use of the Ultrasonic Time of Flight Diffraction (TOFD) Technique
E2700 Practice for Contact Ultrasonic Testing of Welds Using Phased Arrays
F2620 Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings
2.3 ASNT Standards:
ASNT Practice SNT-TC-1A Personnel Qualification and Certification in Nondestructive Testing
ANSI/ASNT-CP-189 Standard for Qualification and Certification of Nondestructive Testing Personnel
2.4 Aerospace Industries Association AIA Document:
NAS 410 Certification and Qualification of Nondestructive Testing Personnel
2.5 ISO Standard:
ISO 9712 Non-Destructive Testing—Qualification and Certification of NDT Personnel
3. Terminology
3.1 Definitions—Related terminology is defined in Terminology E1316.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 butt-fusion joint, n—a joint made by holding the prepared squared ends of two pipes or pipe and fitting against a heated plate
per the conditions of a qualified fusion procedure, which allows for the ends to be brought together after forming the proper melt,
and then allowing the joint to cool while maintaining the appropriate applied force. It is recommended that fusion procedures
comply with Practice F2620.
3.2.2 cell classification, n—for polyethylene pipe resin, this is a six digit code and letter describing the primary properties that are
considered important in the manufacture of PE piping, in the heat fusion joining of this material, in defining the long-term
performance capabilities and color/UV stability. The classification categories are defined in Specification D3350.
3.2.3 dimension ratio (DR), n—this is the average outside pipe diameter divided by the minimum wall thickness.
NOTE 3—The wall thickness increases when the DR decreases.
3.2.3.1 Discussion—
The wall thickness increases when the DR decreases.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
Available from Aerospace Industries Association (AIA), 1000 Wilson Blvd., Suite 1700, Arlington, VA 22209, http://www.aia-aerospace.org.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
E3044/E3044M − 22
NOTE 4—Standard Dimension Ratio (SDR) is an ANSI term to describe specific DRs in the series, for example, DR9, DR11, DR17 and others.
3.2.3.2 Discussion—
Standard Dimension Ratio (SDR) is an ANSI term to describe specific DRs in the series, for example, DR9, DR11, DR17, and
others.
3.2.4 high density polyethylene (HDPE), n—a tough, flexible, thermoplastic resin made by polymerizing ethylene, having a
3 3
density range of >0.940 g/cm to 0.955 g/cm per Specification D3350.
3.2.5 material designations, n—a shortened code to identify the pipe materials short-term and long-term properties.
NOTE 5—For polyethylene, the “PE-XXXX” material designation represents the density (first digit), slow crack growth resistance (second digit) and
hydrostatic design stress (HDS, last two digits) where Specification D3350 is the reference.
3.2.5.1 Discussion—
For polyethylene, the “PE-XXXX” material designation represents the density (first digit), slow crack growth resistance (second
digit), and hydrostatic design stress (HDS, last two digits) where Specification D3350 is the reference.
3.2.6 medium density polyethylene (MDPE), n—a tough, flexible, thermoplastic resin made by polymerizing ethylene, having
3 3
density range of >0.926 g/cm to 0.940 g/cm per Specification D3350.
4. Summary of Practice
4.1 This practice provides a general description of the procedures to carry out ultrasonic examination of polyethylene butt fusion
joints in pipeline systems.
4.2 This practice uses sound waves to inspect butt fusion joints of polyethylene pipe in order to identify and size internal fusion
joint flaws with the intent to non-destructively assess overall joint quality.
4.3 Two procedures are described in this practice that have principles common to those found in Practices E2373 and E2700 where
Time of Flight Diffraction and Phased-Array contact testing are described.
4.4 Examination results using this practice may be used in combination with acceptance criteria based on workmanship or fitness
for purpose.
5. Significance and Use
5.1 This practice is intended primarily for the automated or semi-automated ultrasonic examination of butt fusion joints used in
the construction of polyethylene piping systems.
5.2 Polyethylene piping has been used in lieu of steel alloys in the petrochemical, power, water, gas distribution and mining
industries due to its reliability and resistance to corrosion and erosion. Recently, polyethylene pipe has also been used for nuclear
safety-related cooling water applications.
5.3 Two ultrasonic techniques have proven useful to provide examination of fusion joint integrity; Ultrasonic time-of-flight-
diffraction (TOFD) and phased array ultrasonic testing (PAUT). These techniques are often considered complementary but may
be used independently of each other. The choice of the technique used may depend on a variety of parameters including diameter,
thickness, surface access, detection capabilities near surfaces, and quality level required.
5.4 The joining process can be subject to a variety of flaws including, but not limited to: lack of fusion, particulate contamination,
inclusions, and voids.
5.5 Polyethylene material can have a range of acoustic characteristics that make butt joint examination difficult. Acoustic velocity
of the material is similar to that commonly used for ultrasound wedge materials, making it difficult to use these materials to achieve
appropriate refraction of sound at the interface. Polyethylene materials are highly attenuative, which often limits the use of higher
ultrasonic frequencies. It also exhibits a natural high frequency filtering effect. An example of the range of acoustic characteristics
E3044/E3044M − 22
is provided in Table 1. The table notes the wide range of acoustic velocities reported in the literature. This makes it essential that
the reference blocks are made of the same cell classification as that examined. This shall be confirmed by measuring the acoustic
velocity of the pipe being examined. When using PAUT as the examination technique,examined as described in Practice E494the
. The acoustic velocity of the reference block shall be within 650 m/s of the examined pipe material being examined.
5.6 Polyethylene is reported to have a shear velocity of 987 m/s. However, due to extremely high attenuation in shear mode (on
the order of 5 dB/mm (127 dB/inch)[127 dB/inch] at 2 MHz) no practical examinations are carried out using shear mode (6).
5.7 Due to the wide range of applications, joint acceptance criteria for polyethylene pipe are usually project-specific.
5.8 A typical butt fusion joint in polyethylene pipe has a pronounced bead profile similar to that illustrated in Fig. 1 where the
bead is shown on the outer and inner surface of the pipe.
5.9 TOFD, when used on polyethylene, is simplified in that mode-converted signals are virtually eliminated due to the high
attenuation of the shear mode. However, the near surface and far surface dead zones associated with TOFD may be considered
limitations if determined to be excessive for the detection requirements. For applications on relatively thin wall thickness, for
example, < 15 mm [0.6 in.], one-sided TOFD (or the quasi-chord technique) may be considered to help reduce the extent of these
dead zones. See Annex A2 for details on this option.
5.10 PAUT can be used to address the near surface dead zone that occurs with TOFD.
6. Basis of Application
6.1 The following items are subject to contractual agreement between the parties using or referencing this standard.
6.2 Personnel Qualification—If specified in the contractual agreement, personnel performing examinations to this standard shall
be qualified in accordance with a nationally or internationally recognized NDT personnel qualification practice or standard such
as ANSI/ASNT-CP-189, SNT-TC-1A, NAS-410, ISO 9712, or a similar document and certified by the employer or certifying
agency, as applicable. The practice or standard used and its applicable revision shall be identified in the contractual agreement
between the using parties.
6.3 Qualification of Nondestructive Agencies—If specified in the contractual agreement, NDT agencies shall be qualified and
evaluated as described in Specification E543. The applicable edition of Specification E543 shall be specified in the contractual
agreement.
6.4 Procedures and Techniques—The procedures and techniques to be used shall be as specified in the contractual agreement.
A
TABLE 1 Polyethylene Velocity and Attenuation
Compression Mode Attenuation @2 MHz Attenuation @5 MHz
Velocity (m/s) (in./μs) (dB/mm) (dB/in.) (dB/mm) (dB/in.)
2100 to 2670 0.6 to 1.5 1.1 to 2.3
(0.082 to 0.105) (15.2 to 38) (27.9 to 58)
A
TABLE 1 Polyethylene Velocity and Attenuation
Compression Mode Attenuation @2 MHz Attenuation @5 MHz
Velocity (m/s) [in./μs] (dB/mm) [dB/in.] (dB/mm) [dB/in.]
2100 to 2670 0.6 to 1.5 1.1 to 2.3
[0.082 to 0.105] [15.2 to 38] [27.9 to 58]
A
A range of velocity and attenuation values have been noted in the literature (1-9).
The boldface numbers in parentheses refer to the list of references at the end of
this standard.
When testing in an in-service field condition where the pipe cell classification may not be known, the reference block need only consider the material type (if known),
acoustic velocity and shall be within 650 m ⁄s of the pipe being tested.
The boldface numbers in parentheses refer to athe list of references at the end of this standard.
E3044/E3044M − 22
FIG. 1 Typical Bead Profile for Polyethylene Butt Fusion Joint
6.5 Surface Preparation—The pre-examination surface preparation shall be in accordance with paragraph 7.3.11 and 7.5.8 unless
otherwise specified.
6.6 Timing of Examination—The timing of the examination shall be in accordance with Section 8 unless otherwise specified.
6.7 Extent of Examination—The extent of examination shall include the volume of the joint 10 mm ([ ⁄8 in.),in.], as a minimum,
either side of the fusion line unless otherwise specified in the contract.
6.8 Reporting Criteria—Reporting criteria for the examination results shall be in accordance with Section 8 unless otherwise
specified. Since acceptance criteria are not specified in this standard, they shall be specified in the contractual agreement.
6.9 Re-examination of Repaired/Reworked Items—Re-examination of repaired/reworked items is not addressed in this standard
and if required shall be specified in the contractual agreement.
7. Apparatus and Procedures
7.1 Electronic Instruments and Probes:
7.1.1 The type of instrument(s) used for the examinations specified in Section 7 shall conform to the requirements of Practices
E2373 and E2700 as applicable.
7.1.2 Probes used shall produce pulses with two to three cycles with a nominal center frequency in the range of 1 MHz to 5 MHz.
Refracting wedges should be of a low acoustic velocity and low attenuation material so as to produce a positive refraction relative
to the angle of incidence. Water-gap techniques may be suitable to achieve these conditions.
7.1.3 Wedges shall be contoured to match the pipe curvature when the gap between the wedge and pipe exceeds 0.5 mm (0.02
in.).[0.02 in.]. This is typically required when examining pipe with diameters less than 500 mm (20 in.).[20 in.].
7.2 Standardization Blocks and Other Equipment:
7.2.1 Mechanics:
7.2.1.1 Mechanical holders shall be used to ensure that probe spacing is maintained at a fixed distance from the joint centerline.
The mechanical holders shall also ensure that alignment to the intended scan axis on the examination piece is maintained to a
tolerance agreed upon between contracting parties.
7.2.1.2 Probe motion may be achieved using motorized or manual means but in all cases, the mechanical holder for the probes
shall be equipped with a positional encoder that is synchronized with the sampling of A-scans. Data acquisition shall not exceed
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1 mm (0.04 in.)[0.04 in.] per A-scan sample for pipe diameters up to 500 mm (20 in.)[20 in.] and shall not exceed 2 mm (0.08
in.)[0.08 in.] per A-scan sample for pipe diameters greater than 500 mm (20 in.).[20 in.].
7.2.2 Reference Blocks:
7.2.2.1 Ultrasonic reference blocks are used to standardize the ultrasonic equipment. The ultrasonic characteristics of the reference
blocks, such as attenuation, noise level, surface condition, and sound velocity, should be similar to the material to be examined
per A1.3. Standardization verifies that the instrument and search unit are performing as required and establishes a detection level
for discontinuities. The temperature of the reference blocks shall be within 6 10°C (6 20°F)10 °C [6 20 °F] of the surface of the
joined pipe at the time of examination.
NOTE 3—Environmental conditions at the time of examination may result in some areas of the pipe surface being significantly warmer than others (e.g.,
(for example, exposed to sun versus in shade). This may require standardization at different temperatures.
7.2.3 Reference Reflectors:
7.2.3.1 Flat-bottomed holes, (FBH), Side Drilled Holes (SDH) and notches shall be used as reference targets. SDH shall be used
to establish distance amplitude corrections for PAUT applications. Notches and FBH shall be used to establish sensitivity and
resolution capabilities of the system. Other discontinuities (e.g., (for example, areas of dis-bond or lack of fusion, etc.) may be used
in addition to the required targets. Examples of reference block designs are provided in Annex A1.
7.2.3.2 Sufficient reflectors shall be used to allow assessment of volume coverage, extent of dead zones and to establish reference
sensitivity when the lateral wave or backwall is not present.
7.2.4 Examination of Pipe Material:
7.2.4.1 Prior to the butt fusion joining process, the pipe material approximately 25 to 50 mm (1 to 2 in.) 50 mm [1 to 2 in.] on
each side of the joint should be scanned using a 0° compression mode. Possible conditions or imperfections that may be identified
in the pipe material during this examination include:
(1) Material thickness out of tolerance;
(2) Point reflectors such as poor mixing, porosity, carbon black accumulation, segregation, voids and contamination;
(3) Laminations or inclusions.
7.2.4.2 Such findings or any other indications of poor pipe material quality shall be noted and documented.
NOTE 4—Linear discontinuities such as surface gouges may be identified by TOFD or PAUT signals or during visual assessments of the surface condition
for examination.
7.3 Examination Procedure A, Time of Flight Diffraction (TOFD):
7.3.1 When TOFD is selected as the examination procedure for polyethylene butt fusion joints, the general procedures described
in Practice E2373 are applicable. However, modifications to the recommended probes may be needed due to the shorter wavelength
of the compression mode in polyethylene and its relatively high attenuation.
7.3.2 A project-specific examination procedure, detailing the equipment and setup used, shall be submitted and approved as part
of the contractual agreement.
7.3.3 Probe selection for polyethylene butt fusion joints are found in Tables 2 and 3. These are recommendations and may be
modified for specific materials and project requirements.
7.3.4 For thickness ranges in polyethylene pipe over 25 mm (1 in.),[1 in.], the beam divergence from a single element is not likely
to provide sufficient intensity for good detection over the entire thickness. For thickness 25 mm (1 in.)[1 in.] and greater, the
examination piece should be divided into multiple zones. An example of a multi-zone TOFD configuration for 60 mm thick
material is illustrated in Fig. 2. Table 3 indicates the recommended number of TOFD zones without specifying angles. Probe angles
and probe diameter and frequency shall be selected to ensure full volume coverage.
7.3.5 For thicknesses greater than about 60 mm (2.4 in.),[2.4 in.], other probe frequencies and angles may be required to achieve
adequate volume coverage and flaw detection.
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TABLE 2 For Thickness Ranges up to 25 mm (1 in.)
Nominal
Nominal Wall Element Size Recommended
Frequency
Thickness mm (in.) mm (in.) Angles
(MHz)
<12 (0.5) 2 to 5 6 to 9 (0.25 to 0.375) 65 to 70°
12 to <25 (0.5 to 1.4) 1 to 5 6 to 12.5 (0.25 to 0.5) 60 to 70°
TABLE 2 For Thickness Ranges up to 25 mm [1 in.]
Nominal
Nominal Wall Element Size Recommended
Frequency
Thickness mm [in.] mm [in.] Angles
(MHz)
<12 [0.5] 2 to 5 6 to 9 [0.25 to 0.375] 65 to 70°
12 to <25 [0.5 to 1.4] 1 to 5 6 to 12.5 [0.25 to 0.5] 60 to 70°
TABLE 3 For Thickness Ranges over 25 mm up to 60 mm (1 in.
to 2.4 in.)
Nominal
Nominal Wall Element Size Recommended
Frequency
Thickness mm (in.) mm (in.) Zones
(MHz)
25 (1) to 50 (2) 1 to 5 6 to 12.5 (0.25 to 0.5) 2
>50 to 60 (2 to 2.4) 1 to 5 6 to 12.5 (0.25 to 0.5) 3
TABLE 3 For Thickness Ranges over 25 mm up to 60 mm [1 in.
to 2.4 in.]
Nominal
Nominal Wall Element Size Recommended
Frequency
Thickness mm [in.] mm [in.] Zones
(MHz)
25 [1] to 50 [2] 1 to 5 6 to 12.5 [0.25 to 0.5] 2
>50 to 60 [2 to 2.4] 1 to 5 6 to 12.5 [0.25 to 0.5] 3
7.3.6 Technique capabilities shall be demonstrated on suitably designed reference blocks.
7.3.7 TOFD examination sensitivity may be established using either the responses from the diffraction targets or by material grain
noise. When using the diffraction targets, sensitivity shall be at a level such that the signal to noise ratio is not less than 3:1 for
the pipe material.
7.3.8 When the lateral wave is used to establish reference sensitivity, its amplitude shall be set to produce a non-saturating signal
between 40% and 90% of the screen height. Electronic noise in the region prior to the lateral wave shall be at least 6 dB lower
than the material noise after the lateral wave.
7.3.9 Successful standardization of the TOFD channels will produce clearly defined images of the diffraction notches with the
software-calculated depths to their tips within 0.5 mm (0.02 in.)[0.02 in.] of the actual depths.
7.3.10 Where demonstra
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