ISO 12614-1:2021

INTERNATIONAL ISO
STANDARD 12614-1
Second edition
2021-06
Road vehicles — Liquefied natural gas
(LNG) fuel system components —
Part 1:
General requirements and definitions
Véhicules routiers — Équipements pour véhicules utilisant le gaz
naturel liquéfié (GNL) comme combustible —
Partie 1: Exigences générales et définitions
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Construction and assembly . 4
5 Electrical equipment and wiring . 4
6 Instructions . 5
7 Marking . 5
Annex A (informative) Construction and assembly . 6
Bibliography . 8
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 of gaseous fuels.
This second edition cancels and replaces the first edition (ISO 12614-1:2014), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— editorial changes.
A list of all parts in the ISO 12614 series can be found on the ISO website.
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iv © ISO 2021 – All rights reserved

INTERNATIONAL STANDARD ISO 12614-1:2021(E)
Road vehicles — Liquefied natural gas (LNG) fuel system
components —
Part 1:
General requirements and definitions
1 Scope
This document specifies general requirements and definitions of liquefied natural gas fuel system
components, 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 not applicable to the following:
a) fuel containers;
b) stationary gas engines;
c) container mounting hardware;
d) electronic fuel management;
e) fuelling receptacles.
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 to be considered gauge pressures unless otherwise
specified.
1)
This document is based upon a working pressure for natural gas as fuel of 1,6 MPa [16 bar ]. Other
working pressures can be accommodated by adjusting the pressure by the appropriate factor (ratio).
For example, a 2 MPa (20 bar) working pressure system will require pressures to be multiplied by 1,25.
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 6722 (all parts), Road vehicles — 60 V and 600 V single-core cables
ISO 12614 (all parts), Road vehicles — Liquefied natural gas (LNG) fuel system components
ISO 15500 (all parts), Road vehicles — Compressed natural gas (CNG) fuel system components
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
1) 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.
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/
3.1
burst pressure
static pressure which causes failure and consequential fluid loss through the component envelope
Note 1 to entry: It is the highest pressure during a burst test.
3.2
electronic control unit
ECU
device for control of the engine
3.3
fitting
connector used in joining a piping, tubing, or hose system
3.4
flexible fuel line
flexible tubing or hose through which natural gas flows
3.5
fuel content gauge
system that measures the level of the liquid in the fuel tank
3.6
differential pressure fuel content gauge
fuel content gauge (3.5) based on the difference of the pressure at the top and bottom parts of the fuel
tank (the system measures the weight of the liquid)
3.7
capacitance fuel content gauge
device that measures changes in fuel level through indirect or direct capacitive sensing techniques
3.8
gas temperature sensor
device for gas temperature measurement, which is placed downstream of the vaporizer (3.10)
3.9
gas tight housing
device which vents gas leakage to
...