ISO 20766-25:2022

Road vehicles - Liquefied petroleum gas (LPG) fuel system components - Part 25: Gas connections

This document specifies general requirements and definitions of the gas connection component of liquefied petroleum gas fuel, it is intended for use on the types of motor vehicles as defined in ISO 3833. It also provides general design principles and specifies requirements for instructions and marking. 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. It is recognized that miscellaneous components not specifically addressed herein can be examined for compliance with the criteria of any applicable part of the ISO 20766 series, including testing to the appropriate functional tests. All references to pressure in this document are considered gauge pressures unless otherwise specified. 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).

Véhicules routiers — Équipements pour véhicules utilisant le gaz de pétrole liquéfié (GPL) comme combustible — Partie 25: Raccordements gaz

General Information

• Status: Published
• Publication Date: 03-Jan-2022
• ICS: 43.060.40 - Fuel systems
• Technical Committee: ISO/TC 22/SC 41 - Specific aspects for gaseous fuels
• Drafting Committee: ISO/TC 22/SC 41/WG 6 - Fuel system components and refuelling connector for vehicles propelled by Liquefied Petroleum Gas (LPG)
• Current Stage: 6060 - International Standard published
• Start Date: 04-Jan-2022
• Due Date: 13-Mar-2022
• Completion Date: 04-Jan-2022

Overview

ISO 20766-25:2022 - "Road vehicles - Liquefied petroleum gas (LPG) fuel system components - Part 25: Gas connections" defines general requirements, definitions, design principles, marking and testing requirements for LPG gas connections used on road vehicles (as defined in ISO 3833). The standard applies to mono‑fuel, bi‑fuel and dual‑fuel vehicle applications using gaseous fuels in accordance with ISO 9162 and covers components with service pressures in the range 110 kPa to 840 kPa (gauge pressures). It excludes fuel containers, refuelling receptacles, stationary gas engines, container mounting hardware and electronic fuel management.

Key Topics and Requirements

• Scope & Definitions: Applies to vehicle gas connections within the ISO 20766 series; pressure references are gauge pressure unless stated otherwise. Other service pressures may be accommodated by pressure-ratio adjustment.
• Marking: Components must be traceable and marked with manufacturer/agent name or trademark, model/part number, working pressure (or pressure/temperature range), serial number/date code and flow direction (if required). Additional recommended markings include fuel type, electrical ratings, certification symbol and a reference to ISO 20766-25.
• Construction and Materials:
  • No soldered or welded joints except for attaching parts of detachable couplings to tubes.
  • Gas tubes must use corrosion‑compatible fittings; distribute blocks must be corrosion‑resistant.
  • Joints and fittings must not damage tubes and must meet equal or higher burst pressure than the tube.
  • Minimize number of joints; locate joints for inspection; avoid gas‑carrying connections in passenger compartments except in specified sealed housings or protected filling unit sleeves.
• Testing Requirements (referenced to ISO 20766-2 procedures):
  • Hydrostatic strength: test pressure = 2.25 × working pressure.
  • Continued operation: endurance test for 100 000 cycles.
  • Pull-off: tensile separation test along tube axis; acceptance force F calculated as: F = (π × d × P) / 10 where d = internal diameter in mm, P = maximum working pressure in MPa (bar).
  • Other applicable tests: leakage, excess torque, bending moment, corrosion, vibration, material compatibility and temperature cycling.

Applications and Users

ISO 20766-25 is intended for:

• Automotive OEMs designing LPG fuel systems and component suppliers producing gas connections.
• Test laboratories and conformity assessment bodies performing ISO 20766 series tests.
• Certification agencies and regulators establishing safety and type-approval criteria for LPG vehicle components.
• System integrators and installers ensuring correct selection, marking and installation of gas connections to prevent leaks and galvanic corrosion.

Practical uses include product design validation, production quality control, component marking/traceability and type‑approval testing for LPG vehicle fuel system safety.

Related Standards

• ISO 20766-1 (General requirements and definitions)
• ISO 20766-2 (Performance and general test methods)
• ISO 3833 (Vehicle types - terms and definitions)
• ISO 9162 (Specifications for liquefied petroleum gases)

Keywords: ISO 20766-25, LPG gas connections, road vehicles, liquefied petroleum gas, LPG fuel system components, hydrostatic strength, pull-off test, continued operation.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20766-25
First edition
2022-01
Road vehicles — Liquefied petroleum
gas (LPG) fuel system components —
Part 25:
Gas connections
Véhicules routiers — Équipements pour véhicules utilisant le gaz de
pétrole liquéfié (GPL) comme combustible —
Partie 25: Raccordements gaz
Reference number
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
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Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Markings . 2
5 Construction assembly . 2
6 Tests . 3
6.1 Applicability . 3
6.2 Hydrostatic strength . 3
6.3 Continued operation . 3
6.4 Pull-off. 3
Bibliography . 5
iii
Foreword
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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.
A list of all parts in the ISO 20766 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
INTERNATIONAL STANDARD ISO 20766-25:2022(E)
Road vehicles — Liquefied petroleum gas (LPG) fuel system
components —
Part 25:
Gas connections
1 Scope
This document specifies general requirements and definitions of the gas connection component of
liquefied petroleum gas fuel, it is intended for use on the types of motor vehicles as defined in ISO 3833.
...