ISO 12614-1:2014

INTERNATIONAL ISO
STANDARD 12614-1
First edition
2014-07-01
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 2014
© ISO 2014
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ii © ISO 2014 – 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
Foreword
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The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 25, Vehicles
using gaseous fuels.
ISO 12614 consists of the following parts, under the general title Road vehicles — Liquefied natural gas
(LNG) fuel system components:
— Part 1: General requirements and definitions
— Part 2: Performance and general test methods
— Part 3: Check valve
— Part 4: Manual valve
— Part 5: Tank pressure gauge
— Part 6: Overpressure regulator
— Part 7: Pressure relief valve
— Part 8: Excess flow valve
— Part 9: Gas-tight housing and ventilation hose
— Part 10: Rigid fuel line in stainless steel
— Part 11: Fittings
— Part 12: Rigid fuel line in material other than stainless steel
— Part 13: Pressure control regulator
— Part 14: Differential pressure fuel content gauge
— Part 15: Capacitance fuel content gauge
iv © ISO 2014 – All rights reserved

— Part 16: Heat exchanger - vaporizer
— Part 17: Natural gas detector
— Part 18: Gas temperature sensor
INTERNATIONAL STANDARD ISO 12614-1:2014(E)
Road vehicles — Liquefied natural gas (LNG) fuel system
components —
Part 1:
General requirements and definitions
1 Scope
This part of ISO 12614 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 part of ISO 12614 is not applicable to the following:
a) fuel containers;
b) stationary gas engines;
c) container mounting hardware;
d) electronic fuel management;
e) fuelling receptacles.
NOTE 1 It is recognized that miscellaneous components, not specifically covered herein can be examined to
meet the criteria of this part of ISO 12614 and tested according to the appropriate functional tests.
NOTE 2 All references to pressure in this part of ISO 12614 are to be considered gauge pressures unless
otherwise specified.
1)
NOTE 3 This part of ISO 12614 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, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 3833:1977, Road vehicles — Types — Terms and definitions
ISO 6722 (all parts), Road vehicles — 60 V and 600 V single-core cables
ISO 15500:2012, 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.
3.1
burst pressure
pressure which causes failure and consequential fluid loss through the component envelope
1) 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm .
3.2
electronic control unit
ECU
device for control of the engine — it is not in the scope of ISO 12614
3.3
filter
component that is intended to remove contaminants from the gas stream
3.4
fitting
connector used in joining a piping, tubing, or hose system
3.5
flexible fuel line
flexible tubing or hose through which natural gas flows
3.6
fuel content gauge
device that shows the liquid fuel level in the fuel tank
3.7
differential pressure fuel content gauge
fuel content gauge 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)
3.8
capacitance fuel content gauge
fuel content gauge based on the relationship between the mass and electrical capacitance of natural gas
3.9
gas-air mixer
device for mixing the gaseous fuel and intake air for the engine
3.10
gas flow adjuster
gas flow restricting device, installed downstream of a pressure regulator, control
...