ISO 15500-17:2021

INTERNATIONAL ISO
STANDARD 15500-17
Third edition
2021-12
Road vehicles — Compressed natural
gas (CNG) fuel system components —
Part 17:
Flexible fuel line
Véhicules routiers — Composants des systèmes de combustible gaz
naturel comprimé (GNC) —
Partie 17: Tuyauterie flexible pour combustible
Reference number
© ISO 2021
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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 Marking . . 2
5 Construction and assembly .2
6 Tests . 3
6.1 Applicability . 3
6.2 Hydrostatic strength . 3
6.3 Continued operation . 4
6.4 Bending . 4
6.5 Pull off . 4
6.6 Electrical conductivity . 5
6.7 Permeability . 5
6.8 Automotive fluid . 5
6.9 Verification of hose cover perforations . 6
6.10 Vibration resistance . . 7
6.10.1 General . 7
6.10.2 Method of test . 7
Bibliography . 8
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
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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).
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 41,
Specific aspects for gaseous fuels.
This third edition cancels and replaces the second edition (ISO 15500-17:2012), which has been
technically revised. It also incorporates the Amendment ISO 15500-17:2012/Amd 1:2016.
The main changes are as follows:
— serial number or data code changed from recommended to mandatory in Clause 4 "Marking";
— addition of requirements in Clause 5 "Construction and assembly";
— addition of the following tests:
— automotive fluids,
— verification of hose cover perforations,
— vibration resistance.
A list of all parts in the ISO 15500 series can be found on the ISO website.
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
For the purposes of this document, all fuel system components in contact with natural gas have
been considered suitable for natural gas as defined in ISO 15403-1. However, it is recognized that
miscellaneous components not specifically covered herein can be examined to meet the criteria of this
document and tested according to the appropriate functional tests.
All references to pressure in this document are considered to be gauge pressures unless otherwise
specified.
1)
This document is based on a service pressure for natural gas used as fuel of 20 MPa [200 bar ] settled
at 15 °C. Other service pressures can be accommodated by adjusting the pressure by the appropriate
factor (ratio). For example, a 25 MPa (250 bar) service pressure system will require pressures to be
multiplied by 1,25.
5 2
1) 1 bar = 0,1 MPa = 10 Pa 1 MPa = 1 N/mm .
v
INTERNATIONAL STANDARD ISO 15500-17:2021(E)
Road vehicles — Compressed natural gas (CNG) fuel system
components —
Part 17:
Flexible fuel line
1 Scope
This document specifies tests and requirements for the flexible fuel line, a compressed natural gas
(CNG) fuel system component in accordance with SAE J517 (100R8 hose) or JIS B 8362 intended for use
on the types of motor vehicles defined in ISO 3833.
This document is applicable to vehicles (mono-fuel, bi-fuel or dual-fuel applications) using natural gas in
accordance with ISO 15403-1. It is not applicable to the following:
a) liquefied natural gas (LNG) fuel system components located upstream of, and including, the
vaporizer;
b) fuel containers;
c) stationary gas engines;
d) container-mounting hardware;
e) electronic fuel management;
f) refuelling receptacles.
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 15500-1, Road vehicles — Compressed natural gas (CNG) fuel system components — Part 1: General
requirements and definitions
ISO 15500-2:2016, Road vehicles — Compressed natural gas (CNG) fuel system components — Part 2:
Performance and general test methods
ISO 15500-19, Road vehicles — Compressed natural gas (CNG) fuel system components — Part 19: Fittings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 15500-1 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 Marking
Marking of the component shall provide sufficient information to allow the following to be traced:
a) the manufacturer’s or agent’s name, trademark or symbol;
b) the model designation (part number);
c) the working pressure or pressure and temperature range;
d) the serial number or date code.
The following additional markings are recommended:
— the direction of flow (when necessary for correct installation);
— the type of fuel;
— electrical ratings;
— the symbol of the certification agency;
— the type approval number;
— a reference to this document.
NOTE This information can be provided by a suitable identification code on at least one part of the component
when it consists of more than one part.
5 Construction and assembly
The flexible fuel line shall comply with the applicable provisions of ISO 15500-1 and ISO 15500-2, and
with the tests specified in Clause 6. Tolerances should follow the specifications of ISO 15500-2.
5.1 The nominal hose diameter shall refer to the finished internal diameter ±0,65 mm for sizes up
to and including 20 mm and ±1,25 mm for sizes over 20 mm. A tapered plug gauge having a taper of
30 mm/m marked to indicate variation of 0,5 mm in diameter or other equivalent means may be used
for measuring inside diameter.
5.2 If an outer hose cover is used, it shall be constructed to minimize or prevent fluid penetration
into the inner plies, braids, or tube. The inner plies, braids, or tube shall be resistant to the effects of
common automotive fluids, as determined by the method of test in 6.8 .
5.3 Hose assemblies shall have end fittings that comply with ISO 15500-19 and that are permanently
attached. Fittings or threaded end connectors shall be faced or otherwise finished externally to provide
a standard wrench flat grip.
5.4 In addition to the instruction in ISO 15500-1:2015, Clause 6, the following shall be included as a
minimum:
a) the hose or hose assembly shall not be kinked, twisted or torqued;
b) contact with foreign objects or substances shall be avoided;
c) the manufacturers specified minimum hose bend radius shall be noted and not be exceeded;
d) the manufacturer shall provide appropriate installation instructions with cautionary notes for leak
testing;
e) the manufacturer shall provide installation instructions that state that the hose assembly shall be
of adequate length for the intended use. Hose assemblies shall not be joined together to achieve the
required length; and
f) the hose assembly shall be inspected prior to installation in accordance with the manufacturer's
instructions. The manufacturer's instructions shall address such items as:
i) soft spots, bulges or blisters in the hose;
ii) excessive abrasion exposing the hose reinforcement;
iii) cuts or cracks in the hose that expose or damage the reinforcement; and
iv) evidence of fitting movement or slippage with respect to the hose.
6 Tests
6.1 Applicability
The tests required to be carried out are indicated in Table 1.
Table 1 — Applicable tests
Test procedure as re- Specific test requirements
Test Applicable
quired by ISO 15500-2 of this document
Hydrostatic strength X X X (see 6.2)
Leakage X X
a
Excess torque resistance X X
Bending moment
Continued operation X X X (see 6.3)
Corrosion resistance X X
Oxy
...