ISO 12614-15:2021
(Main)Road vehicles - Liquefied natural gas (LNG) fuel system components - Part 15: Capacitance fuel content gauge
Road vehicles - Liquefied natural gas (LNG) fuel system components - Part 15: Capacitance fuel content gauge
This document specifies tests and requirements for the capacitance fuel content gauge, a liquefied natural gas fuel system component intended for use on the types of motor vehicles defined in ISO 3833.This document is applicable to vehicles using natural gas in accordance with ISO 15403-1 (mono-fuel, bi-fuel, or dual-fuel applications). 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 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. This document is based upon a working pressure for natural gas as a fuel of 1,6 MPa [16 bar1]. Other working pressures can be accommodated by adjusting the pressure by the appropriate factor (ratio). For example, 2 MPa (20 bar) working pressure system will require pressures to be multiplied by 1,25. 1 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1N/mm2.
Véhicules routiers — Équipements pour véhicules utilisant le gaz naturel liquéfié (GNL) comme combustible — Partie 15: Jauge de capacité
General Information
- Status
- Published
- Publication Date
- 03-Jun-2021
- Technical Committee
- ISO/TC 22/SC 41 - Specific aspects for gaseous fuels
- Current Stage
- 6060 - International Standard published
- Start Date
- 04-Jun-2021
- Due Date
- 08-Jan-2022
- Completion Date
- 04-Jun-2021
Relations
- Effective Date
- 23-Apr-2020
Overview - ISO 12614-15:2021 (Capacitance fuel content gauge)
ISO 12614-15:2021 specifies tests and requirements for the capacitance fuel content gauge, a component of liquefied natural gas (LNG) fuel systems for road vehicles (types defined in ISO 3833). It applies to vehicles using natural gas per ISO 15403-1 (mono‑fuel, bi‑fuel, dual‑fuel). The standard covers construction, marking, functional description and a set of applicable tests for the gauge and its electrical interfaces. It excludes fuel containers, stationary gas engines, container mounting hardware, electronic fuel management and refuelling receptacles.
Keywords: ISO 12614-15, LNG fuel system, capacitance fuel content gauge, LNG gauge, road vehicles.
Key topics and technical requirements
Construction and components
- Capacitance transmitter (mounted adjacent to fuel tank), fuel content indicator (dashboard), capacity transmission cables and signal cable.
- The gauge measures capacitance between the tank outer vessel and the inner-vessel sensor cable and converts it to an electrical signal (e.g., 4 mA to 20 mA) compatible with the dashboard indicator.
- The fuel content indicator is an automotive-type gauge calibrated to the transmitter and is not itself tested under this part.
Marking and traceability
- Mandatory markings: manufacturer/agent name or trademark, model designation (part number), and temperature range.
- Recommended: flow direction, fuel type, electrical ratings, certification symbol, type approval number, serial/date code, and reference to ISO 12614-15.
Testing requirements
- Lists applicable functional and durability tests (referencing ISO 12614-2 for methods), including:
- Excess torque resistance, bending moment
- Corrosion resistance, oxygen ageing
- Electrical overvoltages, vibration resistance
- Brass material compatibility
- Insulation resistance: apply 1 000 V d.c. between a connector pin and housing for at least 2 s; minimum allowable resistance 240 kΩ.
- All pressure references are gauge pressures; nominal working pressure is 1.6 MPa (16 bar). Other pressures are accommodated by proportional scaling (e.g., 2 MPa → multiply pressures by 1.25).
- Lists applicable functional and durability tests (referencing ISO 12614-2 for methods), including:
Applications and who uses this standard
- Component manufacturers designing or certifying LNG capacitance gauges
- Vehicle OEMs and integrators specifying LNG fuel-system components
- Testing and certification bodies conducting conformity and safety testing
- Fleet operators and maintenance engineers requiring compliant replacement parts
- Regulatory and type-approval authorities evaluating LNG vehicle systems
Practical benefits: ensures electrical safety, mechanical robustness, interoperability with dashboard indicators, and traceability for LNG vehicle fuel systems.
Related standards
- ISO 12614-1 - General requirements and definitions (LNG fuel system components)
- ISO 12614-2 - Performance and general test methods
- ISO 3833 - Road vehicle types, terms and definitions
- ISO 15403-1 - Natural gas quality for vehicle fuel
For procurement, design or compliance work involving LNG capacitance gauges, reference ISO 12614-15:2021 alongside ISO 12614-1 and ISO 12614-2.
Frequently Asked Questions
ISO 12614-15:2021 is a standard published by the International Organization for Standardization (ISO). Its full title is "Road vehicles - Liquefied natural gas (LNG) fuel system components - Part 15: Capacitance fuel content gauge". This standard covers: This document specifies tests and requirements for the capacitance fuel content gauge, a liquefied natural gas fuel system component intended for use on the types of motor vehicles defined in ISO 3833.This document is applicable to vehicles using natural gas in accordance with ISO 15403-1 (mono-fuel, bi-fuel, or dual-fuel applications). 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 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. This document is based upon a working pressure for natural gas as a fuel of 1,6 MPa [16 bar1]. Other working pressures can be accommodated by adjusting the pressure by the appropriate factor (ratio). For example, 2 MPa (20 bar) working pressure system will require pressures to be multiplied by 1,25. 1 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1N/mm2.
This document specifies tests and requirements for the capacitance fuel content gauge, a liquefied natural gas fuel system component intended for use on the types of motor vehicles defined in ISO 3833.This document is applicable to vehicles using natural gas in accordance with ISO 15403-1 (mono-fuel, bi-fuel, or dual-fuel applications). 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 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. This document is based upon a working pressure for natural gas as a fuel of 1,6 MPa [16 bar1]. Other working pressures can be accommodated by adjusting the pressure by the appropriate factor (ratio). For example, 2 MPa (20 bar) working pressure system will require pressures to be multiplied by 1,25. 1 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1N/mm2.
ISO 12614-15:2021 is classified under the following ICS (International Classification for Standards) categories: 43.060.40 - Fuel systems. The ICS classification helps identify the subject area and facilitates finding related standards.
ISO 12614-15:2021 has the following relationships with other standards: It is inter standard links to ISO 12614-15:2014. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ISO 12614-15:2021 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 12614-15
Second edition
2021-06
Road vehicles — Liquefied natural gas
(LNG) fuel system components —
Part 15:
Capacitance fuel content gauge
Véhicules routiers — Équipements pour véhicules utilisant le gaz
naturel liquéfié (GNL) comme combustible —
Partie 15: Jauge de capacité
Reference number
©
ISO 2021
© ISO 2021
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
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Published in Switzerland
ii © ISO 2021 – All rights reserved
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Marking . 2
5 Construction and assembly . 2
6 Test . 3
6.1 Applicability . 3
6.2 Insulation resistance . 3
Bibliography . 4
Foreword
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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 12614-15:2014), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— editorial changes.
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