ISO 7745:2010 油圧作動油の動力—耐火性（FR）作動油—使用の要件とガイドライン | ページ 2

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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, 2.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

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.

ISO 7745 was prepared by Technical Committee ISO/TC 28, Petroleum products and lubricants, Subcommittee SC 4, Classifications and specifications.

This second edition cancels and replaces the first edition (ISO 7745:1989), which has been technically revised.

Introduction

In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an enclosed circuit. The most widely used liquid for hydraulic power systems is mineral oil which has advantages of excellent lubricity, availability in a wide range of viscosities and reasonable cost.

While not readily ignited in bulk, mineral oil is nevertheless flammable, and the high pressures associated with hydraulic systems can lead to a release of fluid which is easily ignited. In circumstances where ignition is likely, such as in a steel mill, or where released fluid cannot be allowed to propagate a fire, as in a coal mine, an alternative, fire-resistant, fluid must be used. Fire-resistance and physical properties such as viscosity and lubricity vary widely among the several types of fluid available. It is important therefore to select a fire-resistant fluid to match its proposed application and the perceived hazards in use.

1 Scope

This International Standard specifies the operational characteristics for the various categories of fire-resistant fluids defined by ISO 6743-4. This International Standard details the factors to be considered when selecting a fluid from these categories for a proposed application.

This International Standard identifies difficulties which might arise from the use of such fluids and indicates how they may be minimized. Appropriate procedures are given for replacing one fluid with another from a different category. Health and safety aspects when handling and disposing of fire-resistant fluids are also covered.

This International Standard does not apply to fire-resistant fluids used in the hydraulic systems of commercial or military aircraft. The appropriate aviation standards are also usually applied where aircraft hydraulic fluids are filled into ground-based systems.

2 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

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