ISO 10156:2017 ガスボンベ—ガスとガス混合物—ボンベの出口を選択するための火災の可能性と酸化能力の決定 | ページ 2

3.1 用語と定義

このドキュメントでは、次の用語と定義が適用されます。

ISO と IEC は、次のアドレスで標準化に使用する用語データベースを維持しています。

3.2 アイコン

i	ガス混合物中のithの可燃性ガスのモル分率 (%)
k	ガス混合物中のkのthガスのモル分率 (%)
C i	酸素当量係数
i	ith混合ガス中の可燃性ガス
kは	ガス混合物中のkthの不活性ガス
n	混合ガス中の可燃性ガスの数
p	ガス混合物中の不活性ガスの数
k	窒素に対する不活性ガスの当量係数 (表 1 を参照)
	可燃性ガスの等価含有量
i	可燃性ガスの空気中での可燃性下限
T_	窒素と混合した場合に空気中で可燃性ではない可燃性ガスの最大含有量 (%)
i	酸化成分のモル分率、%
he	ヘリウム
ar	アルゴン
ne	ネオン
kr	クリプトン
セ	キセノン
N 2	窒素
H2	水素
O 2	空気
co2	二酸化炭素
so2	二酸化硫黄
O_	亜酸化窒素
SF6	六フッ化硫黄
CF4	四フッ化炭素
C3F8__	オクタフルオロプロパン
C2HF5_	ペンタフルオロエタン
ch_	メタン

3.3 台

このドキュメントの目的のために、すべてのガスのパーセンテージ (%) は、通常の大気条件下での体積分率 (vol. %) に相当するモル分率 (mol. %) として与えられます。

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

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 ).

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents ).

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html .

This document was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 2, Cylinder fittings.

This fourth edition cancels and replaces the third edition (ISO 10156:2010), which has been technically revised. It also incorporates ISO 10156:2010/Cor 1:2010.

The main changes compared to the previous edition are as follows:

• 4.1, 4.2.5 and 4.4 have been technically revised;
• 4.5 and 4.6 have been added.

Introduction

ISO 5145 specifies the dimensions of different cylinder valve outlets for different compatible gas groups. These compatible gas groups are determined according to practical criteria defined in ISO 14456.

These criteria are based on certain physical, chemical, toxic and corrosive properties of the gases. In particular, the flammability in air and the oxidizing ability are considered in this document.

One of the potential complications that prompted the development of this document is that while there are abundant data in the literature relating to pure gases, differences can be found, depending upon the test methods employed. In the case of gas mixtures, data in the literature are often incomplete or even non-existent.

The initial aim of this document was to eliminate the ambiguities in the case of differences in the literature, and above all, to supplement existing data (mainly in the case of gas mixtures).

Subsequently, this document was used for other purposes than the selection of cylinder valve outlets, such as establishing flammability and oxidizing potential data for the classification and labelling of gases and gas mixtures.

This document is intended to be used under a variety of national regulatory regimes, but has been written so that it is suitable for the application of the UN Model Regulations and the UN-GHS^[9].

1 Scope

This document specifies methods for determining whether or not a gas or gas mixture is flammable in air and whether a gas or gas mixture is more or less oxidizing than air under atmospheric conditions.

This document is intended to be used for the classification of gases and gas mixtures including the selection of gas cylinder valve outlets.

This document does not cover the safe preparation of these mixtures under pressure and at temperatures other than ambient.

2 Normative references

There are no normative references in this document.

3 Terms, definitions, symbols and units

3.2 Symbols

Ai	molar fraction of the ith flammable gas in a gas mixture, in %
Bk	molar fraction of the kth inert gas in a gas mixture, in %
Ci	coefficient of oxygen equivalency
Fi	ith flammable gas in a gas mixture
Ik	kth inert gas in a gas mixture
n	number of flammable gases in a gas mixture
p	number of inert gases in a gas mixture
Kk	coefficient of equivalency of an inert gas relative to nitrogen (see Table 1)
	equivalent content of a flammable gas
Li	lower flammability limit in air of a flammable gas
Tci	maximum content of flammable gas which, when mixed with nitrogen, is not flammable in air, in %
xi	molar fraction of the oxidizing component, in %
he	helium
ar	argon
ne	neon
kr	krypton
Xe	xenon
N2	nitrogen
H2	hydrogen
O2	oxygen
co2	carbon dioxide
so2	sulfur dioxide
N2O	nitrous oxide
SF6	sulfur hexafluoride
CF4	carbon tetrafluoride
C3F8	octafluoropropane
C2HF5	pentafluoroethane
ch4	methane

Bibliography