ISO 8625-1:2018

Aerospace — Fluid systems — Vocabulary — Part 1: General terms and definitions related to pressure

ISO 8625-1:2018 defines general terms relating to pressure in fluid systems used in aerospace construction.

Aéronautique et espace — Systèmes de fluides — Vocabulaire — Partie 1: Termes généraux et définitions relatifs à la pression

General Information

• Status: Published
• Publication Date: 18-Mar-2018
• ICS: 01.040.49 - Aircraft and space vehicle engineering (Vocabularies)
• ICS: 49.080 - Aerospace fluid systems and components
• Technical Committee: ISO/TC 20/SC 10 - Aerospace fluid systems and components
• Drafting Committee: ISO/TC 20/SC 10/WG 9 - Hydraulic power and actuation equipment
• Current Stage: 6060 - International Standard published
• Start Date: 19-Mar-2018
• Completion Date: 19-Mar-2018

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 8625-1
Second edition
2018-03
Aerospace — Fluid systems —
Vocabulary —
Part 1:
General terms and definitions related
to pressure
Aéronautique et espace — Systèmes de fluides — Vocabulaire —
Partie 1: Termes généraux et définitions relatifs à la pression
Reference number
ISO 8625-1:2018(E)
ISO 2018
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ISO 8625-1:2018(E)
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© ISO 2018

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ii © ISO 2018 – All rights reserved
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ISO 8625-1:2018(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

Annex A (informative) Graphical presentation of an arbitrary pressure curve ......................................................6

Bibliography ................................................................................................................................................................................................................................ 7

© ISO 2018 – All rights reserved iii
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ISO 8625-1:2018(E)
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, 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).

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 20, Aircraft and space vehicles,

Subcommittee SC 10, Aerospace fluid systems and components.

This second edition cancels and replaces the first edition (ISO 8625-1:1993) which has been technically

revised and includes the following changes:
— Clause 2 “Normative References” has been added;
— Terms and definitions” has been moved from Clause 2 to Clause 3;
— example for a definition at the beginning of Clause 3 has been deleted;
— definitions in Clause 3 have been renumbered accordingly;
— definitions of the following terms have been revised:

— absolute pressure, ambient pressure, atmospheric pressure, burst pressure, control pressure,

dynamic pressure, flushing pressure, idling pressure, maximum pressure, minimum operating

pressure, nominal/system/rated pressure, operating pressure, peak pressure, pressure curve,

pressure drop, pressure impulse, pressure rise, pressure surge, pressure transient, pressure

head, proof pressure, static pressure, suction pressure; and
— the “Alphabetical Index” has been deleted.
A list of all parts in the ISO 8625 series can be found on the ISO website.
iv © ISO 2018 – All rights reserved
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INTERNATIONAL STANDARD ISO 8625-1:2018(E)
Aerospace — Fluid systems — Vocabulary —
Part 1:
General terms and definitions related to pressure
1 Scope

This document defines general terms relating to pressure in fluid systems used in aerospace

construction.
2 Normative references
There are no normative references in this document.
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

NOTE A graphical representation of an arbitrary pressure curve is shown in Annex A.

3.1
absolute pressure

pressure using absolute vacuum as a reference, equal to gauge pressure plus atmospheric pressure

3.2
actual pressure

pressure at a specific location, temperature and time within a system or component

3.3
ambient pressure
pressure on an object caused by its surrounding medium
3.4
atmospheric pressure
absolute pressure of the atmosphere at a specific location and time
3.5
back pressure
pressure acting against the specified direction of operation
3.6
breakout pressure

minimum pressure required to overcome static friction in a component under defined conditions

3.7
burst pressure, actual

pressure at which a component bursts or shows excessive leakage due to structural failure

© ISO 2018 – All rights reserved 1
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ISO 8625-1:2018(E)
3.8
burst pressure, minimum
ultimate pressure, minimum
pressure up to which no burst or rupture of components is allowed
3.9
certification pressure
authorized pressure for official acceptance tests
...