ISO 27126:2021

INTERNATIONAL ISO
STANDARD 27126
Second edition
Thermoplastic multi-layer (non-
vulcanized) hoses and hose
assemblies for the transfer of
hydrocarbons, solvents and
chemicals — Specification
Tuyaux et flexibles multicouches (non vulcanisés) thermoplastiques
pour le transfert des hydrocarbures, des solvants et des produits
chimiques — Spécifications
PROOF/ÉPREUVE
Reference number
ISO 27126:2021(E)
©
ISO 2021

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ISO 27126:2021(E)

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© ISO 2021
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Published in Switzerland
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ISO 27126:2021(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3  Terms and definitions . 2
4  Classification . 2
5 Materials and construction . 3
5.1 General . 3
5.2 Internal and external wire . 3
6 Dimensions . 3
6.1 Inside diameters, with tolerances and minimum bend radii . 3
6.2 Tolerance on length . 4
7 Performance requirements of hoses and hose assemblies . 4
7.1 Cover . 4
7.2 Hoses . 4
7.3 End fittings . 5
7.4 Hose assemblies . 5
7.5 Electrical continuity . 6
8 Test frequency . 6
9 Type tests . 6
10 Marking . 7
10.1 Hose marking . 7
10.2 Hose assembly marking . 7
Annex A (informative) Resistance to chemical(s) conveyed . 8
Annex B (normative) Carbon steel wire . 9
Annex C (normative) Galvanized zinc coating .11
Annex D (normative) Method of test for crush recovery .12
Annex E (normative) Method of test for fuel resistance .14
Annex F (normative) Method of test for thermal ageing .15
Annex G (normative) Method of test for flammability .16
Annex H (normative) Sequence of hydrostatic tests .18
Annex I (normative) Method of test for fitting security.19
Annex J (normative) Method of test for leak tightness .20
Annex K (normative) Type and routine tests for hoses and hose assemblies .21
Annex L (informative) Batch tests for hoses and hose assemblies.22
Bibliography .23
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ISO 27126:2021(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 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 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 45, Rubber and rubber products,
Subcommittee SC 1, Rubber and plastics hoses and hose assemblies.
This second edition cancels and replaces the first edition (ISO 27126:2014), which has been technically
revised, based on EN 13765:2018.
The main changes compared to the previous edition are as follows:
— the normative references have been updated and changed (Clause 2);
— lower minimum and/or higher maximum temperature have been added upon agreement with the
manufacturer (Clause 4);
— some austenitic steel wire has been added (Clause 5);
— change in length and twist at proof pressure instead maximum working pressure have been
modified (Clause 7);
— the electrical resistance requirement between end fittings has been modified (Clause 7);
— marking of the hose and assembly has been updated (Clause 10);
— in Annex D, thickness has been replaced by outside diameter (equals to the distance between the
two plates) and tolerances on test force have been added;
— in Annex H, requirements have been added;
— in Annex K and Annex L, tests requirements 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.
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INTERNATIONAL STANDARD ISO 27126:2021(E)
Thermoplastic multi-layer (non-vulcanized) hoses and
hose assemblies for the transfer of hydrocarbons, solvents
and chemicals — Specification
WARNING — Persons using this document should be familiar with normal laboratory practice.
This document does not purport to address all the safety problems, if any, associated with its
use. It is the responsibility of the user to establish appropriate health and safety practices and to
determine the applicability of any other restrictions.
1 Scope
This document specifies requirements for four types of thermoplastic multi-layer (non-vulcanized)
hoses and hose assemblies for carrying hydrocarbons, solvents and chemicals. It specifies bore sizes
from 25 mm to 300 mm, working pressures from 0,4 MPa (4 bar) to 1,4 MPa (14 bar) and working
temperatures from −30 °C to 150 °C, according to type.
Type 1 hoses are suitable for vapour applications. Types 2 to 4 hoses are suitable for liquid applications.
NOTE 1 See Annex A concerning the selection of the material for the inner wall of layers and any polymeric
coating of the internal wire helix related to the chemical(s) to be conveyed by the hoses and/or hose assemblies.
NOTE 2 It is intended that the manufacturer be consulted where a polymeric coated internal wire is being
considered for use with low conductivity hydrocarbons or chemicals.
This document does not apply to hoses and hose assemblies for:
— aircraft refuelling (see ISO 1825);
— fuel dispensing (see ISO 5772);
— oil burners (see ISO 6806);
— liquefied petroleum gas and liquefied natural gas (see ISO 27127);
— fire fighting (see ISO 14557);
— offshore liquefied natural gas (see EN 1474-2);
— refrigeration circuits.
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 209, Aluminium and aluminium alloys — Chemical composition
ISO 1043-1, Plastics — Symbols and abbreviated terms — Part 1: Basic polymers and their special
characteristics
ISO 1402:2021, Rubber and plastics hoses and hose assemblies — Hydrostatic testing
ISO 1817:2015, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids
ISO 2411, Rubber- or plastics-coated fabrics — Determination of coating adhesion
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ISO 27126:2021(E)

ISO 4671, Rubber and plastics hoses and hose assemblies — Methods of measurement of the dimensions of
hoses and the lengths of hose assemblies
ISO 7233:2021, Rubber and plastics hoses and hose assemblies — Determination of resistance to vacuum
ISO 7326:2016, Rubber and plastics hoses — Assessment of ozone resistance under static conditions
ISO 8031:2020, Rubber and plastics hoses and hose assemblies — Determination of electrical resistance
and conductivity
ISO 8330, Rubber and plastics hoses and hose assemblies — Vocabulary
ISO 10619-1, Rubber and plastics hoses and tubing — Measurement of flexibility and stiffness — Part 1:
Bending tests at ambient temperature
ISO 10619-2, Rubber and plastics hoses and tubing — Measurement of flexibility and stiffness — Part 2:
Bending tests at sub-ambient temperatures
ISO 16143-3:2014, Stainless steels for general purposes — Part 3: Wire
EN 590, Automotive fuels — Diesel — Requirements and test methods
EN 10088-3:2014, Stainless steels — Part 3: Technical delivery conditions for semi-finished products, bars,
rods, wire, sections and bright products of corrosion resisting steels for general purposes
3  Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8330 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 https:// www .electropedia .org/
4  Classification
Hoses shall be classified according to working pressure and working temperature range as given in
Table 1.
Table 1 — Pressure and temperature range
Type 1 Type 2 Type 3 Type 4
MPa bar MPa bar MPa bar MPa bar
Maximum working pressure 0,4 4 1,0 10 1,4 14 1,4 14
Proof pressure 0,6 6 1,5 15 2,1 21 2,1 21
Minimum burst pressure 1,6 16 4 40 5,6 56 5,6 56
Vacuum rating 0,05 0,5 0,09 0,9 0,09 0,9 0,09 0,9
Working temperature range (°C) −20 to +60 −30 to +80 −30 to +80 −30 to +150
NOTE  1 bar = 0,1 MPa.
Upon agreement with the manufacturer, lower minimum and/or higher maximum temperature
are allowed depending on the materials used and the compatibility with the fluid conveyed at those
temperatures. Other properties and requirements mentioned in this document shall be met.
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ISO 27126:2021(E)

5 Materials and construction
5.1 General
Hoses shall be constructed as shown in Figure 1 and shall consist of the following:
— an internal wire helix (see 5.2);
— a multi-ply wall of layers of films and fabrics made of thermoplastics that in combination give the
required properties and provide a complete seal (see also Annex A);
— a cover consisting of a fabric with abrasion resistant polymeric coating;
— an external wire helix (see 5.2).
5.2 Internal and external wire
Wire shall be chosen in accordance with its chemical resistance from one of the following materials:
— austenitic stainless steel wire conforming to EN 10088-3:2014, Table 2, numbers 1.4306, 1.4401,
1.4404 or 1.4436 (X3CrNiMo17-13-3) or ISO 16143-3:2014, Table 1: X2CrNi19-11, X5CrNiMo17-12-2,
X2CrNiMo17-12-2;
— carbon steel wire conforming to Annex B and either galvanised in accordance with Annex C
or sheathed in a polymeric material of a minimum wall thickness of 0,5 mm, resistant to liquid
hydrocarbon or liquid chemicals as agreed between purchaser and manufacturer (see Annex A);
— aluminium wire conforming to ISO 209.
Key
1 internal wire
2 film
3 fabric
4 external wire
Figure 1 — Section of a typical thermoplastic multi-layer hose
6 Dimensions
6.1 Inside diameters, with tolerances and minimum bend radii
When measured in accordance with ISO 4671, the value of the inside diameter of the hose shall conform
to Table 2. When tested by the method specified in ISO 10619-1 the value of the minimum bend radius
shall be as given in Table 2. The hose shall show no sign of permanent deformation of the cross-section
i.e. kinking.
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ISO 27126:2021(E)

Table 2 — Dimensions and minimum bend radii
Dimensions in millimetres, except where specified as “inch”
Inside diameter Tolerance Minimum bend radii
 Type 1 Type 2 Type 3 Type 4
mm inch
25 1 ±1 125 125 200 200
32 1.1/4 ±1 150 150 200 200
38 1.1/2 ±1 150 150 200 200
40 1.1/2 ±1 150 150 200 200
50 2 ±1 200 200 225 225
65 2.1/2 ±2 200 200 225 225
75 3 ±2 280 280 300 300
80 3 ±2 300 300 350 350
100 4 ±2 400 400 400 400
125 5 ±2 500 500 500 —
150 6 ±2 575 575 575 —
200 8 ±3 800 800 800 —
250 10 ±3 1 000 1 000 1 000 —
300 12 ±3 1 200 1 200 1 200 —
6.2 Tolerance on length
When tested in accordance with ISO 4671, the tolerance on the measured length of delivered hose
assemblies shall be +2 % to −1 %.
7 Performance requirements of hoses and hose assemblies
7.1 Cover
When tested in accordance with ISO 2411, the adhesion between the fabric used for the outer cover and
its abrasion resistant coating shall be not less than 1,5 kN/m.
7.2 Hoses
When tested in accordance with the methods given in Table 3, the physical properties of the hoses shall
conform to Table 3.
Table 3 — Physical properties of hoses
Property Unit Requirements Method(s)
ISO 1402 with pressure in-
MPa No leakage or other signs of damage at pres-
Proof pressure crease not less than 0,17 MPa/
(bar) sure given in Table 1.
min (1,7 bar/min)
ISO 1402:2021, 8.2 with the
Change in length at proof initial length measured when
% 10
pressure (max.) the hose is pr
...