ISO/FDIS 4070

Polyvinylidene fluoride (PVDF) — Effect of time and temperature on expected strength

This document specifies the minimum values for expected strength as a function of time and temperature in the form of reference lines, for use in calculations on Polysulfone (PSU) injection moulded piping components. This document is applicable for polysulfone (PSU) homopolymer compounds only.

Polyfluorure de vinylidène (PVDF) — Influence du temps et de la température sur la résistance attendue

General Information

• Status: Not Published
• ICS: 83.080.20 - Thermoplastic materials
• 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 - General properties of pipes, fittings and valves of plastic materials and their accessories -- Test methods and basic specifications
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 04-Mar-2025
• Due Date: 04-Mar-2025
• Completion Date: 04-Mar-2025

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/TC 138/SC 5
Polyvinylidene fluoride (PVDF) —
Secretariat: NEN
Effect of time and temperature on
Voting begins on:
expected strength
2025-03-04
Polyfluorure de vinylidène (PVDF) — Influence du temps et de la
Voting terminates on:
température sur la résistance attendue
2025-04-29
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
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
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.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 138/SC 5
Polyvinylidene fluoride (PVDF) —
Secretariat: NEN
Effect of time and temperature on
Voting begins on:
expected strength
Polyfluorure de vinylidène (PVDF) — Influence du temps et de la
Voting terminates on:
température sur la résistance attendue
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.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Basic formulae . 1
5 Expected strength . 2
5.1 Extrapolation limits .2
5.2 Graphical representation .3
5.3 Tabulated values .3
6 Demonstrating conformance . 3
7 Derivation of wall thickness . . 3
Annex A (normative) Demonstrating conformance to the reference lines . 6
Annex B (informative) Derivation of S values . 7
calc,max
Bibliography .10

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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
Introduction
In the early 2000s, manufacturers of plastics and multilayer piping systems for hot and cold-water
installations began to consider the use of alternative plastics materials beside the widely used metallic
materials (e.g. copper alloys or stainless steel) for components and fittings. Before this point, however,
no materials were available which had the high material strengths which are required for fittings and
components.
With the market availability of polyvinylidene fluoride (PVDF), polysulfone (PSU) and polyphenylsulfone
(PPSU), the option for the use of plastics materials, instead of metallic materials, for fittings and components,
as part of plastics and multilayer piping systems, was made possible and products mainly produced by
injection moulding, have been introduced into the market.
In the beginning, the design and the calculation for the dimensions was based on individual ISO 9080
analyses for each individual PVDF/PSU/PPSU compound.
This document has been developed with the intention of aligning the values for the expected strength over
the time (reference lines) for PVDF/PSU/PPSU, in order to simplify and unify all design procedures for which
the expected strength over the time is needed.
The reference lines for polyvinylidene fluoride (PVDF) referred to in this document have been agreed upon
by a group of experts from ISO/TC 138, SC 5 after considering experimental data, and have been accepted
by the relevant ISO technical committees.
At the date of publication of this document, the following International Standards dealing with plastics and
multilayer piping systems for hot and cold water installations have been published:
— ISO 15874 series, Plastics piping systems for hot and cold water installations - Polypropylene (PP)
— ISO 15875 series. Plastics piping systems for hot and cold water installations - Crosslinked
polyethylene (PE-X)
— ISO 15876 series, Plastics piping systems for hot and cold water installations - Polybutene (PB)
— ISO 15877 series, Plastics piping systems for hot and cold water installations - Chlorinated poly(vinyl
chloride) (PVC-C)
— ISO 22391 series, Plastics piping systems for hot and cold water installations - Polyethylene of raised
temperature resistance (PE-RT)
— ISO 21003 series, Multilayer piping systems for hot and cold water installations inside buildings

v
FINAL DRAFT International Standard ISO/FDIS 4070:2025(en)
Polyvinylidene fluoride (PVDF) — Effect of time and
temperature on expected strength
1 Scope
This document specifies the minimum values for expected strength as a function of time and temperature in
the form of reference lines, for use in calculations on polyvinylidene fluoride (PVDF) homopolymer extruded
pipes and injection moulded fittings.
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 1167-1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the
resistance to internal pressure — Part 1: General method
ISO 1167-2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the
resistance to internal pressure — Part 2: Preparation of pipe test pieces
ISO 9080:2012, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
thermoplastics materials in pipe form by extrapolation
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
reference lines
generic description of the minimum long-term hydrostatic strength to be expected from a particular polymer
Note 1 to entry: Reference lines are not intended to be considered as being characteristic of a specific grade or of
material from a specific supplier.
Note 2 to entry: The lines are described by a mathematical equation which permits interpolation and extrapolation in
an unambiguous way within the applicable temperature and time ranges
4 Basic formulae
The reference lines, described by Formulae (1) and (2), are applicable for temperatures between 10 °C and 120 °C.
First branch: log t= A + B /T + C log σ + (D /T) log σ (1)
10 1 1 1 10 1 10
Second branch: log t = A + B /T + C log σ + (D /T) log σ (2)
10 2 2 2 10 2 10
where
t is the time, in hours;
T is the temperature, in Kelvin;
σ is the hoop stress, in Megapascal.
The lower value obtained from Formula (1) or Formula (2), respectively, represents the expected hoop
strength.
First branch:
A = −165,495 8
B = 78 465,65
C = 57,046 7
D = −36 518,7
i.e. log t = –165,495 8 + 78 465,65/T + 57,046 7 log σ – (36 518,7/T) log σ
10 10 10
Second branch:
A = −23,194 26
B = 12 100
C = −0,404 73
D = −1 611,69
i.e. log t = – 23,194 26 + 12 100/T – 0,404 73 log σ – (1 611,69/T) log σ
10 10 10
5 Expected strength
5.1 Extrapolation limits
The extrapolation limits, i.e. time limit for which extrapolation is allowed, are based on an experimentally
determined time at 110 °C and the Arrhenius equation for the temperature dependence, with an activation
energy of 110 kJ/mole (26 kcal/mole). See ISO 9080:2012, 5.2.
NOTE A conservative approach has been taken by basing the analysis on the activation energy for polyolefins,
110 kJ/mol, for hot and cold-water applications. If experimental evidence can be given that other extrapolation time
factors are justified, these can be used instead of the factors given in Table 1 of ISO 9080:2012.
The values given in Table 1 are the minimum required extrapolation time limits for PVDF materials according
to this document.
Table 1 — Minimum extrapolation time limits (based on 1 year testing at 110 °C)
T
...

2024-11-11
ISO/DISFDIS 4070 : 2024(en)
ISO/TC 138/SC 5/WG 5
Secretariat: NEN
Date: 2025-02
Polyvinylidene fluoride (PVDF) — Effect of time and temperature on
expected strength
Polyfluorure de vinylidène (PVDF) — Influence du temps et de la température sur la résistance attendue
FDIS stage
ISO/DISFDIS 4070:2024(E2025(en)
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 on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva.
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO/DISFDIS 4070:20242025(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Basic formulae . 1
5 Expected strength . 2
5.1 Extrapolation limits . 2
5.2 Graphical representation . 3
5.3 Tabulated values . 3
6 Demonstrating conformance . 3
7 Derivation of wall thickness . 3
Annex A (normative) Demonstrating conformance to the reference lines . 8
Annex B (informative) Derivation of S values . 9
calc,max
Bibliography . 12

iii
ISO/DISFDIS 4070:2024(E2025(en)
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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/DISFDIS 4070:20242025(en)
Introduction
In the early 2000s, manufacturers of plastics and multilayer piping systems for hot and cold-water
installations began to consider the use of alternative plastics materials beside the widely used metallic
materials (e.g. copper alloys or stainless steel) for components and fittings. Before this point, however, no
materials were available which had the high material strengths which are required for fittings and
components.
With the market availability of (Polyvinylidenepolyvinylidene fluoride (PVDF), Polysulfonepolysulfone (PSU)
and Polyphenylsulfonepolyphenylsulfone (PPSU), the option for the use of plastics materials, instead of
metallic materials, for fittings and components, as part of plastics and multilayer piping systems, was made
possible and products mainly produced by injection moulding, have been introduced into the market.
In the beginning, the design and the calculation for the dimensions was based on individual ISO 9080 analyses
for each individual PVDF/PSU/PPSU compound.
This document has been developed with the intention of aligning the values for the expected strength over the
time (reference lines) for PVDF/PSU/PPSU, in order to simplify and unify all design procedures for which the
expected strength over the time is needed.
The reference lines for polyvinylidene fluoride (PVDF) referred to in this document have been agreed upon by
a group of experts from 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), after considering experimental data, and have been accepted by the relevant ISO
technical committees.
At the date of publication of this International Standarddocument, the following International Standards
dealing with plastics and multilayer piping systems for hot and cold water installations have been published:
— — ISO 15874 series, Plastics piping systems for hot and cold water installations - Polypropylene (PP)
— — ISO 15875 series. Plastics piping systems for hot and cold water installations - Crosslinked
polyethylene (PE-X)
— — ISO 15876 series, Plastics piping systems for hot and cold water installations - Polybutene (PB)
— — ISO 15877 series, Plastics piping systems for hot and cold water installations - Chlorinated poly(vinyl
chloride) (PVC-C)
— — ISO 22391 series, Plastics piping systems for hot and cold water installations - Polyethylene of raised
temperature resistance (PE-RT)
— — ISO 21003 series, Multilayer piping systems for hot and cold water installations inside buildings
v
ISO/DISFDIS 4070:20242025(en)
Polyvinylidene fluoride (PVDF) — Effect of time and temperature on
expected strength
1 Scope
This document specifies the minimum values for expected strength as a function of time and temperature in
the form of reference lines, for use in calculations on polyvinylidene fluoride (PVDF) homopolymer extruded
pipes and injection moulded fittings.
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 1167--1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the
resistance to internal pressure — Part 1: General method
ISO 1167--2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the
resistance to internal pressure — Part 2: Preparation of pipe test pieces
ISO 9080:2012, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
thermoplastics materials in pipe form by extrapolation
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
3.1 3.1
reference lines
generic description of the minimum long-term hydrostatic strength to be expected from a particular polymer
Note 1 to entry: Reference lines are not intended to be considered as being characteristic of a specific grade or of material
from a specific supplier.
Note 2 to entry: The lines are described by a mathematical equation which permits interpolation and extrapolation in an
unambiguous way within the applicable temperature and time ranges
4 Basic formulae
The reference lines, described by Formulae (1)Formulae (1) and (2)(2),, are applicable for temperatures
between 10 °C and 120 °C.
First branch:    log t log t= A + B /T + C log σlog σ + (D /T) log σlog σ (1)
10 10 1 1 1 10 10 1 10 10
Second branch:  log t log t = A + B /T + C log σlog σ + (D /T) log σlog σ (2)
10 10 2 2 2 10 10 2 10 10
where
ISO/DISFDIS 4070:2024(E2025(en)
t is the time, in hours;
T is the temperature, in Kelvin;
σ is the hoop stress, in Megapascal.
The lower value obtained from Formula (1)Formula (1) or Formula (2)Formula (2),, respectively, represents
the expected hoop strength.
First branch:
A = −165,4958495 8
B = 78 465,65
C = 57,0467046 7
D = −36 518,7
i.e. log t = –165,4958495 8 + 78 465,65/T + 57,0467046 7 log σ – (36 518,7/T) log σ
10 10 10
Second branch:
A = −23,19426194 26
B = 12 100
C = −0,40473404 73
D = −1 611,69
i.e. log10 t = – 23,19426194 26 + 12 100/T – 0,40473404 73 log10 σ – (1 611,69/T) log10 σ
5 Expected strength
5.1 Extrapolation limits
The extrapolation limits, i.e. time limit for which extrapolation is allowed, are based on an experimentally
determined time at 110 °C and the Arrhenius equation for the temperature dependence, with an activation
energy of 110 kJ/mole (26 kcal/mole). See ISO 9080:2012, 5.2.
NOTE A conservative approach has been taken by basing the analysis on the activation energy for polyolefins,
110 kJ/mol, for Hothot and Coldcold-water applications. If experimental evidence can be given that other extrapolation
time factors are justified, these can be used instead of the factors given in Table 1 of ISO 9080:2012.
The values given in Table 1Table 1 are the minimum required extrapolation time limits for PVDF materials
according to this document.
Table 1 — Minimum extrapolation time limits (based on 1 year testing at 110 °C)
Temperature Extrapolation time limit
°C years
a
96 - 100 2,5
91 - 95 4
ISO/DISFDIS 4070:20242025(en)
Temperature Extrapolation time limit
°C years
86 - 90 6
81 - 85 12
76 - 80 18
71 - 75 30
61 - 70 50
≤ 60 100
a
Experimentally determined.
With a testing time other than 1 year at 110 °C, the extrapolation limit shall be calculated using the
extrapolation factors given in ISO 9080:2012, 5.2.
5.2 Graphical representation
Figure 1Figure 1 contains the reference lines for PVDF corresponding to the values of the parameters given in
Clause 4Clause 4 with extrapolation time limits based on testing of 1 year at 120 °C.
5.3 Tabulated values
The calculated hoop strength values to be used for various temperatures and times are given in
Table 2Table 2. These values include no safety factors or design factors. They are based on extrapolated time
limits as given in Table 1Table 1.
6 Demonstrating conformance
To demonstrate conformance to the requirements of this document (reference lines), the procedure given in
Annex AAnnex A shall apply.
7 Derivation of wall thickness
In Annex BAnnex B,, the principles regarding the derivation of minimum wall thicknesses of piping
components relative to the application classes are specified.

ISO/DISFDIS 4070:2024(E2025(en)

ISO/DISFDIS 4070:20242025(en)
Key
Y stress (MPa)
X1 time (h)
X2 time (years)
Figure 1 — Expected strength o
...