ISO/TS 22499:2019

Thermoplastic pipes for the conveyance of fluids - Inspection of polyethylene butt fusion joints using phased array ultrasonic testing

This document describes the phased array ultrasonic testing (PAUT) of polyethylene butt fusion (BF) joints, including pipe-to-pipe, pipe-to-fitting and fitting-to-fitting joints, used for the conveyance of fluids. This document provides a test, whereby the presence of imperfections such as voids, inclusions, lack of fusions, misalignment and particulate contamination in the BF joints can be detected. The document is only applicable to polyethylene pipes and fittings without a barrier to ultrasonic waves. This document also provides requirements for procedure qualification and guidance for personnel qualifications, which are essential for the application of this test method. This document also covers the equipment, the preparation and performance of the test, the indication assessment and the reporting for polyethylene BF joints. The assessment of ultrasonic indications and acceptance criteria are not covered in this document. NOTE 1 At the present time, laboratory experiences exist on the use of PAUT for polyethylene BF joints and/or reference blocks of wall thickness between 8 mm to 100 mm[1] to [5]. Recently, field experience on BF joints in PE80 and PE100 materials has been reported[6]. NOTE 2 Round robin testing has shown that PAUT is a viable method for enhancing the integrity assessment of BF joints[7]. NOTE 3 PAUT techniques for cold fusion detection are known to be available. However further research, verification and experience are needed to transfer the technique into an ISO Standard. This document does not provide any information regarding the detection of cold fusions.

Tubes en matières thermoplastiques pour le transport des fluides - Contrôle des assemblages par soudage bout à bout en polyéthylène au moyen de la technique par ultrasons multi-éléments

General Information

• Status: Withdrawn
• Publication Date: 30-Sep-2019
• ICS: 23.040.20 - Plastics pipes
• Technical Committee: ISO/TC 138/SC 5 - General properties of pipes, fittings and valves of plastic materials and their accessories -- Test methods and basic specifications
• Drafting Committee: ISO/TC 138/SC 5/WG 17 - Alternative test methods
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 15-Feb-2024
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO/TS 22499:2024 - Thermoplastic pipes for the conveyance of fluids - Inspection of polyethylene butt fusion joints using phased array ultrasonic testing
• Effective Date: 06-Jun-2022

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 22499
First edition
2019-10
Thermoplastic pipes for the
conveyance of fluids — Inspection of
polyethylene butt fusion joints using
phased array ultrasonic testing
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Information required prior to testing . 3
4.1 Items required for procedure . 3
4.2 Specific information required by the operator before testing . 3
4.3 Written test procedure . 3
5 Personnel qualifications. 3
6 Equipment . 4
6.1 General . 4
6.2 Ultrasonic instrument and display . 4
6.3 Ultrasonic probes . 4
6.4 Scanning mechanisms. 4
6.5 Couplant . 5
7 Range and sensitivity settings . 5
7.1 Settings . 5
7.1.1 General. 5
7.1.2 Range setting — Test volume . 5
7.1.3 Sensitivity setting . 6
7.2 Reference sample . 7
7.2.1 General. 7
7.2.2 Reference block . 7
7.2.3 Reference reflectors . 7
7.3 Checking of the settings . 7
8 Equipment checks . 8
9 Test procedure . 8
9.1 Procedure qualification . 8
9.2 Scan increment . 9
9.3 Component geometry . 9
9.4 Preparation of scanning surfaces . 9
9.5 Component temperature . 9
9.6 Testing . 9
9.7 Data storage . 9
10 Interpretation and analysis of test data . 9
10.1 General . 9
10.2 Assessing the quality of the test data .10
10.3 Identification of relevant indications .10
10.4 Classification of relevant indications .10
10.5 Determination of location and size of indications .10
10.6 Assessment of indications .10
11 Test report .11
Annex A (informative) Example of reference reflectors and reference blocks .13
Annex B (informative) Example procedures for producing imperfections in BF joints .17
Bibliography .21
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves
for the transport of fluids, Subcommittee SC 5, General properties of pipes, fittings and valves of plastic
materials and their accessories — Test methods and basic specifications.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved

TECHNICAL SPECIFICATION ISO/TS 22499:2019(E)
Thermoplastic pipes for the conveyance of fluids —
Inspection of polyethylene butt fusion joints using phased
array ultrasonic testing
1 Scope
This document describes the phased array ultrasonic testing (PAUT) of polyethylene butt fusion (BF)
joints, including pipe-to-pipe, pipe-to-fitting and fitting-to-fitting joints, used for the conveyance of
fluids. This document provides a test, whereby the presence of imperfections such as voids, inclusions,
lack of fusions, misalignment and particulate contamination in the BF joints can be detected. The
document is only applicable to polyethylene pipes and fittings without a barrier to ultrasonic waves.
This document also provides requirements for procedure qualification and guidance for personnel
qualifications, which are essential for the application of this test method.
This document also covers the equipment, the preparation and performance of the test, the indication
assessment and the reporting for polyethylene BF joints. The assessment of ultrasonic indications and
acceptance criteria are not covered in this document.
NOTE 1 At the present time, laboratory experiences exist on the use of PAUT for polyethylene BF joints and/
[1] to [5]
or reference blocks of wall thickness between 8 mm to 100 mm . Recently, field experience on BF joints in
[6]
PE80 and PE100 materials has been reported .
NOTE 2 Round robin testing has shown that PAUT is a viable method for enhancing the integrity assessment
[7]
of BF joints .
NOTE 3 PAUT techniques for cold fusion detection are known to be available. However further research,
verification and experience are needed to transfer the technique into an ISO Standard. This document does not
provide any information regarding the detection of cold fusions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5577, Non-destructive testing — Ultrasonic testing — Vocabulary
ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 13953, Polyethylene (PE) pipes and fittings — Determination of the tensile strength and failure mode of
test pieces from a butt-fused joint
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5577 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
cold fusion
insufficient joint integrity caused by the incomplete intermolecular diffusion of polymer chains for
proper molecular entanglement at the joint interface due to reasons other than contamination, which
does not create any PAUT indication(s) at the joint interface
3.2
inclusion
foreign material trapped in the fusion joint
3.3
lack of fusion
absence of intermolecular diffusion of polymer chains for molecular entanglement at the interface,
resulting in a non-destructive testing indication at the joint interface
3.4
melt fusion zone
MFZ
zone containing the fusion interface and having boundaries on either side of the interface which reflect
the limits of crystalline melting during the BF jointing process
Note 1 to entry: The MFZ is shown in Figure 1.
3.5
misalignment
offset between the axis of the pipes/fittings to be jointed
3.6
particulate contamination
fine particles, e.g. airborne dust, or coarse particles, e.g. sand and grit, that are present at the fusion
interface
3.7
surface imperfection
imperfection on the ID or OD surface of the butt fusion joint
3.8
void
empty space (or air pocket) in a BF joint
3.9
phased array image
one-, two-, or three-dimensional display, constructed from the phased array data
3.10
phased array set-up
probe arrangement defined by probe characteristics (e.g. frequency, probe element size, beam angle,
wave mode), probe position (3.11), and the number of probes
3.11
probe position
point between the front of the wedge (or probe) and the BF centre line
3.12
scan increment
distance between successive data collection points in the direction of scanning
3.13
false call
reporting an imperfection when none exists
2 © ISO 2019 – All rights reserved

4 Information required prior to testing
4.1 Items required for procedure
Information on the following items is required:
— purpose and extent of testing;
— reference sample;
— requirements for getting access to the BF joints, the surface condition of the pipe; and the
temperature range;
— personnel qualifications;
— reporting requirements;
— manufacturing or operation stage of BF joints at which the testing is to be carried out.
4.2 Specific information required by the operator before testing
Before any testing of a fusion joint begins, the operator shall have access to all the information as
specified in 4.1 together with the following additional information:
a) written test procedure;
b) all relevant joint dimensions.
4.3 Written test procedure
For all testing, a written test procedure is required. This test procedure shall include at least the
following information:
a) purpose and extent of testing;
b) reference sample;
c) requirements for access to the BF joints and surface conditions and temperature;
d) personnel qualifications;
e) reporting requirements;
f) equipment requirements and settings (including but not limited to frequency, sampling rate, pitch
between elements and element size);
g) evaluation of indications;
h) environmental and safety issues;
i) documented testing strategy or scan plan.
NOTE The testing strategy gives information on the probe placement, movement, and component coverage
that provides a standardized and repeatable methodology for fusion joint testing. The scan plan gives information
on the volume tested for each BF joint.
5 Personnel qualifications
Personnel performing testing in accordance with this document shall be qualified to an appropriate
level in accordance with ISO 9712 or an equivalent standard in the relevant industrial sector.
In addition to a general knowledge of ultrasonic testing, the operator shall be familiar with and have
practical experience in the use of phased array systems on polyethylene BF joints. Specific theoretical
and practical training and examination of personnel shall be performed on representative polyethylene
BF joints containing natural or artificial reflectors similar to those expected. These training and
examination results shall be documented.
6 Equipment
6.1 General
[8] [9]
For the selection of system components (hardware and software), ISO 13588 and ISO/TS 16829
give useful information.
Ultrasonic equipment used for phased array testing should comply with the requirements of
[10] [11] [12]
ISO 18563-1 , ISO 18563-2 and ISO 18563-3 when applicable.
The complete equipment, i.e. ultrasonic instrument, probe, cables and display monitor, shall be capable
of the repetition of test results.
6.2 Ultrasonic instrument and display
The instrument shall be able to select an appropriate portion of the time base within which A-scans are
digitized. It is recommended that a sampling rate of the A-scan should be at least six times the nominal
probe frequency.
6.3 Ultrasonic probes
Only longitudinal wave mode can be used.
Any type of phased array probe can be used if it satisfies the range and sensitivity setting requirements
of Clause 7 with the phased array equipment.
The most suitable ultrasonic probe frequency should be selected in accordance with the pipe wall
thickness. Table 1 shows the recommended frequencies for each thickness range. However, the optimal
frequency can deviate from these values depending on the attenuation and thickness of the sample to
be tested.
The gap between the test surface and the bottom of the wedge shall not be greater than 0,5 mm.
Table 1 — Selection of probe frequency
Recommended frequency Wall thickness
MHz mm
1,0 to 2,25 60 to 100
2,25 to 4,0 30 to 60
4,0 to 5,0 8 to 30
NOTE In general, higher frequencies provide better resolution and lower frequencies provide better
penetration.
6.4 Scanning mechanisms
To achieve consistency of the images (collected data), guiding mechanisms and scan encoder(s) shall
be used.
4 © ISO 2019 – All rights reserved

6.5 Couplant
In order to generate proper images, a couplant should be used which provides a constant transmission
of ultrasound between the probe and the material. The same couplant used for calibration shall be used
for the testing. Any couplant used should be cleaned off after testing.
7 Range and sensitivity settings
7.1 Settings
7.1.1 General
Setting of range and sensitivity shall be carried out prior to each testing period in accordance with this
document. Any change of the phased array set-up, e.g. probe position and steering parameters, will
require a new setting. The set-up should be optimized on the reference reflectors to give a signal-to-
noise ratio minimum of 6 dB.
7.1.2 Range setting — Test volume
The range in the depth direction shall cover the full joint thickness in the fusion zone.
The range in the axial direction shall cover the MFZ on both sides of the BF centre line. As a general
guidance, for wall thicknesses <100 mm, the test area width is 10 mm or 1/5 of the wall thickness from
either side of the fusion zone, whichever is smaller (see Figure 1).
The range in the circumferential direction shall include the full circumference.
Key
1 outside of joint
2 inside of joint
3 MFZ boundary
4 test area
5 MFZ
6 fusion interface
x width of test area
Figure 1 — Test area
7.1.3 Sensitivity setting
After selection of mode (E-scan, S-scan) the following shall be carried out:
a) sensitivity shall be set for each beam generated by the phased array probe;
1) when a probe with wedge is used, the sensitivity shall be set with the wedge in place,
2) when beam focussing is used, the sensitivity shall be set for each focused beam;
b) use of angle-corrected gain (ACG) or time-corrected gain (TCG) shall be applied to enable the
display of signals for all beam angles and all distances with the same amplitude.
NOTE Different testing techniques of PAUT for BF joints (e.g. fixed angles, E-scans and S-scans at fixed probe
posit
...