ISO 20766-18:2019

INTERNATIONAL ISO
STANDARD 20766-18
First edition
2019-10
Road vehicles — Liquefied petroleum
gas (LPG) fuel systems components —
Part 18:
Hose
Véhicules routiers — Équipements pour véhicules utilisant le gaz de
pétrole liquéfié (GPL) comme combustible —
Partie 18: Tuyauterie
Reference number
©
ISO 2019
© ISO 2019
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Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Markings . 2
5 Construction and assembly . 2
5.1 General specifications . 2
5.2 Rubber hose construction . 3
5.3 Synthetic hose construction . 3
5.4 Couplings for rubber hoses . 3
5.5 Couplings for synthetic hoses . 4
5.6 Assembly of hose and couplings . 4
6 Tests . 4
6.1 Applicability . 4
6.2 Hydrostatic strength . 5
6.3 Low temperature. 5
6.4 High temperature. 5
6.5 Tensile strength and elongation . 5
6.6 Permeability . 6
6.7 Bending test . 6
6.7.1 Bending test for rubber hoses . 6
6.7.2 Bending test for synthetic hoses . 7
6.8 Impulse test . 8
6.9 Gas-tightness . 9
Bibliography .10
Foreword
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 41,
Specific aspects for gaseous fuels.
A list of all parts in the ISO 20766 series can be found on the ISO website.
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iv © ISO 2019 – All rights reserved

INTERNATIONAL STANDARD ISO 20766-18:2019(E)
Road vehicles — Liquefied petroleum gas (LPG) fuel
systems components —
Part 18:
Hose
1 Scope
This document specifies general information regarding the hose component of liquefied petroleum gas
fuel, intended for use on the types of motor vehicles as defined in ISO 3833. It provides general design
principles and specifies requirements for instructions and marking. It also specifies test requirements
for the hose.
This document is applicable to vehicles (mono-fuel, bi-fuel or dual-fuel applications) using gaseous fuels
in accordance with ISO 9162. It is not applicable to the following:
a) fuel containers;
b) stationary gas engines;
c) container mounting hardware;
d) electronic fuel management;
e) refuelling receptacles.
Fully metal bendable hoses are excluded from this document.
NOTE 1 It is recognized that miscellaneous components not specifically addressed herein can be examined
for compliance with the criteria of any applicable part of ISO 20766, including testing to the appropriate
functional tests.
NOTE 2 All references to pressure in this document are considered gauge pressures unless otherwise
specified.
NOTE 3 This document applies to devices which have a service pressure in the range of 110 kPa (Butane rich
at 20 °C) and 840 kPa (Propane at 20 °C), hereinafter referred to in this document. Other service pressures can
be accommodated by adjusting the pressure by the appropriate factor (ratio).
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 37, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
ISO 527-2, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and
extrusion plastics
ISO 1307:2006, Rubber and plastics hoses — Hose sizes, minimum and maximum inside diameters, and
tolerances on cut-to-length hoses
ISO 1436, Rubber hoses and hose assemblies — Wire-braid-reinforced hydraulic types for oil-based or
water-based fluids — Specification
ISO 4080, Rubber and plastics hoses and hose assemblies — Determination of permeability to gas
ISO 20766-1, Road vehicles — Liquefied petroleum gas (LPG) fuel systems components — Part 1: General
requirements and definitions
ISO 20766-2, Road vehicles — Liquefied petroleum gas (LPG) fuel systems components — Part 2:
Performance and general test methods
DIN 7643, Compression couplings — Hollow screws for ring-type banjos
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 20766-1 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 http:// www .electropedia .org/
4 Markings
Every hose shall bear, at intervals of not greater than 0,5 m, the following clearly legible and indelible
identification markings consisting of characters, figures or symbols.
a) the manufacturer’s or agent’s name, trademark or symbol;
b) the model designation (part number);
c) the working pressure and temperature range;
d) the year and month of fabrication;
e) the size and type-marking.
The following additional markings are recommended:
— the direction of flow (when necessary for correct installation);
— the type of fuel;
— the electrical ratings (if applicable);
— the symbol of the certification agency;
— the type approval number;
— the serial number or date code;
— a reference to this document.
NOTE Every coupling bears the trade name or mark of the assembling manufacturer.
5 Construction and assembly
5.1 General specifications
5.1.1 The hose shall be so designed as to withstand maximum operating pressure as applicable.
2 © ISO 2019 – All rights reserved

5.1.2 The hose shall be so designed as to withstand temperatures between the minimum operating
temperature and the maximum operating temperature.
5.1.3 The inside diameter of the hose shall be in compliance with of ISO 1307:2006, Table 1.
5.2 Rubber hose construction
5.2.1 The hose shall embody a smooth-bore tube and a cover of suitable synthetic material, reinforced
with one or more interlayer(s).
5.2.2 The reinforcing interlayer(s) shall be protected by a cover against corrosion. If for the reinforcing
interlayer(s) corrosion-resistant material is used (i.e. stainless steel) a cover is not required.
5.2.3 The lining and cover shall be smooth and free from pores, holes and strange elements. An
intentionally provided puncture in the cover shall not be considered as an imperfection.
5.2.4 The cover shall be intentionally perforated to avoid the forming of bubbles.
5.2.5 When the cover is punctured, and the interlayer is made of a non-corrosion resistant material,
the interlayer shall be protected against corrosion.
5.3 Synthetic hose construction
5.3.1 The synthetic hose shall embody a thermoplastic tube and a cover of suitable thermoplastic
material, oil and weatherproof, reinforced with one or more synthetic interlayer(s). If for the reinforcing
interlayer(s) a corrosion-resistant material is used (i.e. stainless-steel) a cover is not required.
5.3.2 The lining and the cover shall be free from pores, holes and strange elements. An intentionally
provided puncture in the cover shall not be considered as an imperfection.
5.3.3 If the synthetic hose is made out of one material and/or one layer it shall comply with all testing
listed in Table 1 for both liner and cover.
5.4 Couplings for rubber hoses
5.4.1 The couplings shall be made from steel or brass and the surface shall be corrosion resistant.
5.4.2 The coupling burst pressure in mounted position shall never be less than the tube or hose burst
pressure. The coup
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