ISO 161-1:2018

INTERNATIONAL ISO
STANDARD 161-1
Fourth edition
2018-01
Thermoplastics pipes for the
conveyance of fluids — Nominal
outside diameters and nominal
pressures —
Part 1:
Metric series
Tubes en matières thermoplastiques pour le transport des fluides —
Diamètres extérieurs nominaux et pressions nominales —
Partie 1: Série métrique
Reference number
©
ISO 2018
© ISO 2018, Published in Switzerland
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Nominal outside diameter, d . 3
n
5 Nominal pressure rating (PN). 4
6 Minimum required strength (MRS) . 4
Bibliography . 5
Foreword
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electrotechnical standardization.
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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).
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URL: 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.
This fourth edition cancels and replaces the third edition (ISO 161-1:1996), which has been technically
revised.
The significant changes are:
— Nominal diameters are extended up to 3 000 mm;
— Nominal pressure PN 25 bar is added;
— Nominal pressure PN 6 shall be designed using 6,3 bar; designation based on 6,0 bar is deleted;
— MRS values up to 20 are based on R 10 increments. MRS values above 20 are based on R 20 increments;
— Definitions are updated to follow modern plastics piping terminology.
A list of all the parts in the ISO 161 series, can be found on the ISO website.
iv © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 161-1:2018(E)
Thermoplastics pipes for the conveyance of fluids —
Nominal outside diameters and nominal pressures —
Part 1:
Metric series
1 Scope
This document specifies the nominal outside diameters for metric thermoplastics pipes for the
conveyance of fluids in pressure and non-pressure applications. It also specifies nominal pressure
ratings and minimum required strengths for pressure applications.
It is applicable to smooth thermoplastics pipes of constant circular cross-section along the whole length
of the pipe, whatever their method of manufacture or material of construction.
It is not applicable to pipes designated according to the nominal inside diameter DN/ID.
This document is a basis for standards writers for the sele
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