ISO 8575:2016

INTERNATIONAL ISO
STANDARD 8575
Second edition
2016-11-15
Aerospace — Fluid systems —
Hydraulic system tubing
Série aérospatiale — Systèmes de fluides — Tubes pour systèmes
hydrauliques
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
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ii © ISO 2016 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 1
4.1 General . 1
4.2 Pressure lines . 2
4.2.1 Tubing material . 2
4.2.2 Tube sizes . 2
4.2.3 Qualification . 2
4.3 Suction and return lines . 2
4.3.1 Tubing Material . 2
4.3.2 Tube sizes . 2
Annex A (informative) Aerospace hydraulic tubing materials . 8
Bibliography . 9
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
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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, Part 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, Part 2 (see www.iso.org/directives).
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Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 10, Aerospace fluid systems and components.
This second edition cancels and replaces the first edition (ISO 8575:1990), which has been technically
revised.
iv © ISO 2016 – All rights reserved

Introduction
The purpose of this document is to provide information relating to the sizes and materials of tubing for
use in aerospace hydraulic pressure and return and suction lines.
International Standards use the International System of units (SI); however, large segments of the
aerospace industry make use of other measurement systems as a matter of common working practice.
Although tube sizes were originally defined (and are frequently cited) using non-SI units, all dimensions
used in this document are given in SI units, with inch units also indicated for the convenience of the user.
The decimal sign used in International Standards is the comma (“,”); however, the comma is not used
in common working practice for inch dimensions. Therefore, in common with many other aerospace
standards, the decimal point is used in this document when providing dimensions in inches.
NOTE The use of non-SI units and the decimal point in this document does not constitute general acceptance
of measurement systems other than SI within International Standards.
INTERNATIONAL STANDARD ISO 8575:2016(E)
Aerospace — Fluid systems — Hydraulic system tubing
1 Scope
This document provides information relating to the sizes and materials of tubing for use in aerospace
hydraulic pressure and return and suction lines. For pressure lines, the requirements apply to the
pressure and temperature ranges covered by pressure class D, E and J and temperature type 13 and
type 20 as specified in ISO 6771.
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.
ISO 8574, Aerospace — Hydraulic system tubing — Qualification tests for bent tubes
ISO 6771, Aerospace — Fluid systems and components — Pressure and temperature classifications
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp/
3.1
inch — tubing
tubing diameters and wall thickness in fractional inch increments and based on industry standards
3.2
metric tubing
tubing diameters and wall thickness in SI-metric units
Note 1 to entry: Metric tubing is in compliance with ISO 2964.
4 Requirements
4.1 General
The pipe dimensions quoted are in common use for the stated materials in the different pressure and
temperature classes. Inclusion of a dimension under a pressure and temperature class in this document
does not constitute a guarantee of fitness for purpose in all circumstance. Aircraft Systems designers
should verify each tube assembly application with the appropriate stress authority.
4.2 Pressure lines
...