ISO 11425:2018

INTERNATIONAL ISO
STANDARD 11425
Second edition
2018-11
Rubber hoses and hose assemblies for
automobile power-steering systems —
Specification
Tuyaux et flexibles en caoutchouc pour circuits de direction
assistée — Spécifications
Reference number
©
ISO 2018
© ISO 2018
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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 . 2
4 Types of hose . 2
5 Construction and materials . 2
6 Dimensions and tolerances . 2
7 Performance requirement . 3
7.1 Impulse resistance . 3
7.2 Burst pressure requirement . 3
7.3 Change in length . 3
7.4 Low-temperature flexibility . 3
7.5 Adhesion . 4
7.6 Ozone resistance. 4
7.7 Volumetric expansion. 4
7.8 Contamination . 4
7.9 Corrosion of end fittings . 4
7.10 Proof pressure requirement . 4
7.11 Cold-start requirement (type approval test for type 4 hose assemblies only) . 4
7.11.1 Requirement . 4
7.11.2 Test method . 5
7.12 Low-pressure burst pressure requirement (type 4 hose assemblies only) . 5
8 Marking . 5
Annex A (normative) Method of test for volumetric expansion . 6
Annex B (normative) Method of test for contamination . 8
Annex C (informative) Typical outside-diameter ranges .10
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
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.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 45, Rubber & Rubber Products,
Subcommittee SC 1, Rubber and plastics hoses and hose assemblies
This second edition cancels and replaces the first edition (ISO 11425:1996), of which it constitutes a
minor revision.
The main changes compared to the previous edition are as follows:
— In Clause 2, normative references have been updated.
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 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 11425:2018(E)
Rubber hoses and hose assemblies for automobile power-
steering systems — Specification
WARNING — Attention is drawn to the need to ensure that appropriate precautions are taken to
ensure the safety of personnel carrying out the methods of test specified in this document.
1 Scope
This document specifies requirements for five types of hose and hose assembly used in automobile
power-steering systems, the five types differing in their pressure ratings and volumetric expansion.
They are for use with fluids in the temperature range −40 °C to +135 °C.
This document is based on performance tests. In order to take account of technological developments,
no requirements are included for specific materials, detailed construction or manufacturing methods.
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 1402, Rubber and plastics hoses and hose assemblies — Hydrostatic testing
ISO 2719, Determination of flash point — Pensky-Martens closed cup method
ISO 2909, Petroleum products — Calculation of viscosity index from kinematic viscosity
ISO 2977, Petroleum products and hydrocarbon solvents — Determination of aniline point and mixed
aniline point
ISO 3016, Petroleum products — Determination of pour point
ISO 3819, Laboratory glassware — Beakers
ISO 4671, Rubber and plastics hoses and hose assemblies — Methods of measurement of the dimensions of
hoses and the lengths of hose assemblies
ISO 4788, Laboratory glassware — Graduated measuring cylinders
ISO 4793, Laboratory sintered (fritted) filters — Porosity grading, classification and designation
ISO 6803, Rubber or plastics hoses and hose assemblies — Hydraulic-pressure impulse test without flexing
ISO 7326:2016, Rubber and plastics hoses — Assessment of ozone resistance under static conditions
ISO 8033, Rubber and plastics hoses — Determination of adhesion between components
ISO 8330, Rubber and plastics hoses and hose assemblies — Vocabulary
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 10619-2, Rubber and plastics hoses and tubing — Measurement of flexibility and stiffness — Part 2:
Bending tests at sub-ambient temperatures
ISO/TR 11340:1994, Rubber and rubber products — Hydraulic hose assemblies — External leakage
classification for hydraulic systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8330 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
hose assembly
hose with either permanent or re-usable end fittings attached
4 Types of hose
Hoses shall be one of the following five types:
a) Type 1: low-pressure hydraulic fluid return hoses and hose assemblies.
b) Type 2: medium-pressure low volumetric expansion hoses and hose assemblies.
c) Type 3: medium-pressure medium volumetric expansion hoses and hose assemblies.
d) Type 4: medium-pressure high volumetric expa
...