IEC TR 63431:2025
(Main)Optical fibre cables - Microduct technology - Guidance
Optical fibre cables - Microduct technology - Guidance
IEC TR 63431:2025 which is a Technical report, document identifies issues which can be considered when adopting microduct technology for the provision of optical communications networks. It supplements the microduct sections of IEC 60794‑5 series of publications and refers to products and practices in current use. This documents also describes design types, colour codes, repairs, and environmental expectations, including guidance to standards and methods of installation.
General Information
Standards Content (Sample)
IEC TR 63431 ®
Edition 1.0 2025-09
TECHNICAL
REPORT
Optical fibre cables - Microduct technology - Guidance
ICS 33.180.01 ISBN 978-2-8327-0710-4
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CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, and abbreviated terms . 6
3.1 Terms and definitions. 6
3.2 Abbreviated terms . 7
4 Microduct types . 8
4.1 Outdoor . 8
4.2 Indoor . 8
5 Microduct assemblies . 9
5.1 General . 9
5.2 Single thick-walled . 9
5.3 Bundled thick-walled . 9
5.4 Over-sheathed unprotected microducts . 10
6 Microduct sizes – individual products . 10
7 Microduct colouring and identification . 12
8 The use of microducts . 13
8.1 General . 13
8.2 Pushing application . 13
8.3 Blowing application . 14
8.4 Pulling application . 14
8.5 Surface mounted application . 14
9 Microduct properties . 15
9.1 General . 15
9.2 Burst pressure . 15
9.3 Microduct tensile properties . 15
9.4 Temperature performances . 15
9.5 Post shrinkage due to installation tension and relaxation . 15
9.6 Post shrinkage purely due to temperature change . 16
9.6.1 Fibre bundle or small cables . 16
9.6.2 Mini cables and blown cables . 16
9.7 Microduct testing . 16
9.7.1 Installation performance . 16
9.7.2 Long term pressure testing . 17
9.8 Packaging and delivery . 17
9.9 Microduct storage . 18
9.10 Microduct repair . 18
Annex A (informative) Associated documents . 22
Annex B (informative) Associated documents . 23
Bibliography . 24
Figure 1 – Single thick-walled duct . 9
Figure 2 – Bundled thick-walled duct . 9
Figure 3 – Non circular or flat formed bundles . 9
Figure 4 – Over-sheathed unprotected microduct . 10
Figure 5 – Tight protected . 10
Figure 6 – Loose protected . 10
Figure 7 – Example of above ground (aerial) microduct . 14
Figure 8 – Installation simulation test rig . 17
Figure 9 – Detailed alternative scenarios . 19
Figure 10 – Example of gel wrap repair kit . 21
Table 1 – Unprotected microduct dimensions . 11
Table 2 – Protected microduct dimensions (using the same methodology as Table 1) . 12
Table 3 – Identification colours (RAL) . 12
Table 4 – IEC 60757 colour table . 13
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Optical fibre cables - Microduct technology - Guidance
FOREWORD
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IEC TR 63431 has been prepared by subcommittee 86A: Fibre and cables, of IEC technical
committee 86A: Fibre optics. It is a Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
86A/2609/DTR 86A/2620/RVDTR
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Report is English.
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specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
INTRODUCTION
Microduct technology concerns the installation of optical fibre or copper transmission members
into small 'microducts' wh
...
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