ISO 7509:2015 プラスチック配管システム—ガラス繊維強化熱硬化性プラスチック（GRP）パイプ—持続的な内圧下での故障までの時間の決定 | 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.

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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The committee responsible for this document is ISO/TC 138, Plastics pipes, fittings and valves for the transport of fluids, Subcommittee SC 06, Reinforced plastics pipes and fittings for all applications.

This second edition cancels and replaces the first edition (ISO 7509:2000), which has been technically revised.

Introduction

This International Standard describes a method for determining the long-term resistance to internal pressure of glass-reinforced thermosetting plastics (GRP) pipes.

It is a method which uses the following conditions:

• water as the reference liquid inside the test piece;
• water or air, as the environment outside the test piece.

The method can be used for tests at different temperatures. It should be noted that, for a given temperature, the results obtained can differ depending on the end loading conditions and whether the external environment is water or air.

The method described in this International Standard differs from those in some other similar standards in the following details:

• the failure criteria and the detection of failure;
• the strain in the longitudinal and circumferential directions can be measured during the test;
• the test pressure is maintained constant.

This method can be used to obtain data to establish internal pressure versus time-to-failure relationships at different temperatures. The procedures for establishing the relationships are not within the scope of this International Standard. For such purposes, attention is drawn to ISO 10928.

1 Scope

This International Standard specifies a method for determining the time-to-failure of glass-reinforced thermosetting plastics (GRP) pipes under internal hydrostatic pressure at a specified temperature. The external environment can be air or water.

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.

3 Terms and definitions

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