ISO 23309:2020 油圧作動油動力システム—組み立てられたシステム—フラッシングによるラインの洗浄方法 | ページ 2

Foreword

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This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 6, Contamination control.

This second edition cancels and replaces the first edition (ISO 23309:2007) which has been technically revised.

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

• identifies the shortfall of the Reynolds formula when it's used in isolation;
• identifies the importance of flushing oil velocity, temperature, and viscosity;
• identifies to the practitioners who perform flushing procedures that if they only consider the Re value the flushing velocity could be much less than the system oil flow within the system and what it will be subjected to in normal service;
• raises awareness and importance of the factors other than the Re valve that affect the effectiveness, efficiency and reliability of any flushing process.

Introduction

In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an enclosed circuit.

The initial cleanliness level of a hydraulic system can affect its performance and useful life. Unless removed, particulate contamination present after manufacturing, assembly, component failure and repair of a system can circulate through the system and cause damage to the system components. To reduce the probability of such damage, the fluid and the internal surfaces of the hydraulic fluid power system needs to be flushed clean to a specified level.

Flushing of lines in a hydraulic system needs to be viewed as one means of removing in-built and residual contamination and should not be the sole method for cleaning such systems unless other methods are impractical.

1 Scope

This document specifies the procedures for flushing particulate contamination from the hydraulic lines and components of hydraulic fluid power systems which is:

• residual in the components after manufacture;
• introduced into the system during the assembly of a new system; or
• introduced into the system after system failure, maintenance or modification of an existing system.

The aim of flushing the system is to quickly remove this contamination to reduce the amount of wear and damage that results if these particles are allowed to circulate around the system.

This document is not applicable to:

• the chemical cleaning and pickling of hydraulic tubes;
• the cleaning of major system components (this is covered in ISO/TR 10949).

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 5598 and the following apply.

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

Bibliography