ISO 14624-5:2023

Space systems - Safety and compatibility of materials - Part 5: Determination of reactivity of system/component materials with aerospace propellants

This document specifies test equipment and techniques used to identify interactions resulting from exposure of a material to an aerospace fluid. It is applicable for determining interactive reactions between propellants and materials used in the design, construction, and operation of propellant storage, transfer, and flight systems.

Systèmes spatiaux — Sécurité et compatibilité des matériaux — Partie 5: Détermination de la réactivité des matériaux des systèmes/composants avec les ergols spatiaux

General Information

• Status: Published
• Publication Date: 31-May-2023
• ICS: 49.025.01 - Materials for aerospace construction in general
• ICS: 49.140 - Space systems and operations
• Technical Committee: ISO/TC 20/SC 14 - Space systems and operations
• Drafting Committee: ISO/TC 20/SC 14/WG 1 - Design engineering and production
• Current Stage: 6060 - International Standard published
• Start Date: 01-Jun-2023
• Due Date: 20-May-2023
• Completion Date: 01-Jun-2023

Relations

• Revises: ISO 14624-5:2006 - Space systems - Safety and compatibility of materials - Part 5: Determination of reactivity of system/component materials with aerospace propellants
• Effective Date: 23-Aug-2014

Overview

ISO 14624-5:2023 - Space systems - Safety and compatibility of materials - Part 5 specifies test equipment and procedures to determine the reactivity of system and component materials with aerospace propellants. It defines screening and immersion tests to identify interactions between propellants (e.g., hydrazines, nitrogen tetroxide) and materials used in propellant storage, transfer and flight systems. The standard provides semi‑qualitative, accelerated methods (not a full substitute for long‑term exposure testing) and includes safety, sample handling and post‑test analysis requirements.

Key topics and technical requirements

• Scope & purpose: Identify material-fluid interactions that render materials or propellants unsuitable for use; applicable to design, construction and operation of propellant systems.
• Screening test: Short exposure at ambient conditions - apply the test fluid dropwise to a small sample (≤ 0.25 g) for 2 hours; check for visible changes.
• Immersion test: Sample fully immersed (~25 ml, sample area (25 ± 10) cm2) for 48 hours at maximum system temperature or 71 °C (whichever is higher) to accelerate reactions.
• Acceptance criteria:
  • No visible change in colour/texture of material or fluid after decontamination and drying.
  • Mass change of sample ≤ ±2 %.
  • Impurity mass in fluid after exposure ≤ twice that after exposure to reference materials (PTFE for non‑metals; ISO 4954 stainless steel for metals).
  • Halide concentrations must not exceed the fluid purity limits in the relevant ISO fluid specifications.
• Test system & instrumentation:
  • Screening: glass beaker.
  • Immersion: matched sample and reference chambers with temperature and pressure monitoring; differential or absolute pressure transducers as appropriate.
  • Recommended analytical tools for post‑test analysis: DSC, GC, GC‑MS, AAS, ICP‑OES/MS, ion chromatography, HPLC.
• Sample preparation & cleaning: Test in intended use form, clean to end‑use specs, remove particulates with filtered N2 (per ISO 15859‑3).
• Safety & laboratory practices: PPE (face shield, gloves, lab coat/apron), fume hood/engineering controls, calibrated instruments, emergency plan for runaway reactions.

Applications and users

ISO 14624-5:2023 is used by:

• Spacecraft materials engineers and propulsion system designers evaluating material compatibility with propellants.
• Test laboratories developing propellant compatibility test programs.
• Safety officers, procurement teams and qualification engineers assessing component suitability for propellant storage, transfer and flight hardware.
• Suppliers validating materials used in propellant lines, valves, seals and tanks.

Practical benefits include early screening of materials, standardized test procedures for comparison and risk reduction in propellant system design and operation.

Related standards

• ISO 14951‑6 & ISO 14951‑7 (hydrazine propellant characteristics - referenced)
• ISO 15859‑3 (fluid sampling and test methods - nitrogen)
• ISO 4954 (stainless steel reference material)

Keywords: ISO 14624-5:2023, propellant compatibility, space systems, material reactivity, immersion test, screening test, hydrazine, nitrogen tetroxide, aerospace propellants.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 14624-5
Second edition
2023-06
Space systems — Safety and
compatibility of materials —
Part 5:
Determination of reactivity of system/
component materials with aerospace
propellants
Systèmes spatiaux — Sécurité et compatibilité des matériaux —
Partie 5: Détermination de la réactivité des matériaux des systèmes/
composants avec les ergols spatiaux
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Fluid transfer, storage and flight systems . 2
4.1 General . 2
4.1.1 Procedure . 2
4.1.2 Safety . 2
4.2 Test criteria . 2
4.2.1 Screening test . . 2
4.2.2 Immersion test . 2
4.2.3 Post-test analysis . 2
4.3 Sample . 3
4.3.1 Receiving inspection . 3
4.3.2 Sample preparation . 3
4.3.3 Sample cleaning . . 3
4.3.4 Sample inspection . 3
4.4 Test system . 3
4.4.1 Screening test . . 3
4.4.2 Immersion test . 3
4.5 Procedure . 4
4.5.1 Before testing . 4
4.5.2 Test . . . 5
4.5.3 Post-test analysis . 5
4.6 Precision . . . 6
4.7 Good laboratory practices . 6
Annex A (informative) Example forms . 7
Bibliography .10
iii
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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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
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Attention is drawn to the possibility that some of the elements of this document may be the subject of
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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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles,
Subcommittee SC 14, Space systems and operations.
This second edition cancels and replaces the first edition (ISO 14624-5:2006), which has been
technically revised.
The main changes are as follows:
— updated sections of Clause 4.
A list of all parts in the ISO 14624 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
This purpose of this document is to identify changes resulting from exposure of a material to an
aerospace fluid that renders either the material or the fluid unsuitable for use.
This document can be used to determine the reactivity of system and component materials with
aerospace fluids.
While this procedure is an excellent quick screen test for long-term propellant compatibility, it is
semi-qualitative, and (if exposures exceed 12 months) long-term tests need to be used to quantify
degradation as a function of time under use conditions.
v
INTERNATIONAL STANDARD ISO 14624-5:2023(E)
Space systems — Safety and compatibility of materials —
Part 5:
Determination of reactivity of system/component
materials with aerospace propellants
1 Scope
This document specifies test equipment and techniques used to identify interactions resulting from
exposure of a material to an aerospace fluid.
It is applicable for determining interactive reactions between propellants and materials used in the
design, construction, and operation of propellant storage, transfer, and flight systems.
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 4954, Steels for cold heading and cold extruding
ISO 15859-3, Space systems — Fluid characteristics, sampling and test methods — Part 3: Nitrogen
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
degradation
adverse physical or chemical change in a substance
3.2
immersion test
test in which the fluid covers the entire sample for the duration of the test
3.3
propellant
fluid, such as hydrazine and monomethylhydrazine, and oxidizer usually used for space projects
3.4
reaction
chemical change in
...