ISO 12614-8:2021 道路車両—液化天然ガス（LNG）燃料システムコンポーネント—パート8：過剰流量バルブ | ページ 2

Foreword

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The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, 2 (see www.iso.org/directives ).

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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 12614-8:2014), 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.

1 Scope

This document specifies tests and requirements for the excess flow valve, 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 bar ¹ ). 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.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 12614-1 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

Bibliography