ISO 4076:2025

International
Standard
ISO 4076
First edition
Polyphenylsulfone (PPSU) —
2025-04
Effect of time and temperature on
expected strength
Polyphénylsulphone (PPSU) — Influence du temps et de la
température sur la résistance attendue
Reference number
© ISO 2025
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Published in Switzerland
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 .2
5.3 Tabulated values .4
6 Demonstrating conformance . 5
7 Derivation of wall thickness . . 5
Annex A (normative) Demonstrating conformance to the reference lines . 6
Annex B (informative) Derivation of S values. 7
calc,max
Bibliography .10

iii
Foreword
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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
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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, no materials
were available which had the high material strengths that are required for fittings and components.
With the market availability of Polyvinylidenefluoride (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 molding have been introduced into the market.
In the beginning, the design and the calculation for the dimensioning 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 polyphenylsulfone (PPSU) 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 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
International Standard ISO 4076:2025(en)
Polyphenylsulfone (PPSU) — 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 polyphenylsulfone (PPSU) 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 — Deter
...