ISO 16438:2021

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 16438
ISO/TC 23/SC 18
Agricultural irrigation equipment —
Secretariat: SII
Thermoplastic collapsible hoses for
Voting begins on:
2021­06­02 irrigation — Specifications and test
methods
Voting terminates on:
2021­07­28
Matériel agricole d'irrigation — Tuyaux écrasables en matières
thermoplastiques pour l'irrigation — Spécifications et méthodes
d'essai
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 16438:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2021

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ISO/FDIS 16438:2021(E)

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© ISO 2021
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ii © ISO 2021 – All rights reserved

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ISO/FDIS 16438:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
5 Material . 2
6 Marking . 3
7 Dimensions . 3
7.1 Inside diameter . 3
7.2 Length . 3
7.3 Spacing of outlet connections . 3
8 Fittings . 3
9 Hydrostatic and hydraulic characteristics . 3
9.1 Proof pressure test . 3
9.2 Deformation under pressure and after relaxation . 4
9.3 Warping . 4
9.4 Head loss . 4
10 Physical characteristics . 4
10.1 Opacity . 4
10.2 UV resistance . 5
Bibliography . 6
© ISO 2021 – All rights reserved iii

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ISO/FDIS 16438:2021(E)

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 non­governmental, 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 23, Tractors and machinery for agriculture
and forestry, Subcommittee SC 18, Irrigation and drainage equipment and systems.
This second edition cancels and replaces the first edition (ISO 16438:2012), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the PVC layflat hoses are excluded from this document;
— some definitions have been updated;
— some changes in pressure tests parameters and procedure have been applied;
— marking the word "irrigation" became optional.
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 2021 – All rights reserved

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ISO/FDIS 16438:2021(E)

Introduction
Thermoplastic collapsible hoses have been introduced to agricultural irrigation projects in recent
years, as headers supplying drip tape systems or as replacement for gated pipes.
Thermoplastic collapsible hoses for irrigation are a special type of hoses. They have a unique
combination of attributes and requirements which must be well specified and controlled, but are not
covered by any other International Standard:
— equal and accurate spacing of multiple water outlet connections along their length;
— low elongation and amo
...