ISO 8575:2024

Overview

ISO 8575:2024 sets out guidelines for the selection of sizes and materials for tubing used in aerospace hydraulic systems. Published by the International Organization for Standardization (ISO), this standard forms part of the Aerospace series, focusing specifically on hydraulic pressure, return, and suction lines within fluid systems. The requirements for pressure lines address the pressure and temperature classes described in ISO 6771, ensuring compatibility and safety across diverse aerospace applications.

The document includes detailed information on permissible tubing dimensions (both in inch and metric units), material properties, and qualification processes, providing essential support for design engineers, manufacturers, and quality assurance professionals in the aerospace sector.

Key Topics

• Tubing Sizes and Materials:

  • Provides standardized dimensions for tubing used in aerospace hydraulic lines, with tables listing approved diameter and wall thickness combinations.
  • Covers materials such as corrosion-resistant steels, titanium alloys, and aluminium alloys, with references to corresponding national and international standards.

• Hydraulic Systems Classification:

  • Aligns tubing requirements with specific pressure classes (D, E, J) and temperature types (Type 13 and Type 20) as outlined in ISO 6771.
  • Differentiates between tubing needed for pressure lines (subjected to higher loads and thermal stresses) and those for suction and return lines.

• Qualification and Verification:

  • Requires tubing to meet specified physical and mechanical properties.
  • Stipulates that qualification testing for tube assemblies must comply with ISO 8574.
  • Encourages system designers to verify tubing choices with relevant stress authorities.

• International Alignment:

  • Cross-references ISO and other global standards to ensure interoperability.
  • Tables include SI and inch units, accommodating regional industry practices.

Applications

• Aerospace Hydraulic Systems:

  • ISO 8575:2024 is essential for designing and maintaining hydraulic circuits in both civil and military aircraft, as well as space vehicles.
  • Used by system designers to select suitable tubing for critical fluid conveyance applications, including landing gear, flight control, and braking systems.

• Manufacturing and Quality Assurance:

  • Manufacturers utilize these requirements to ensure tubing conforms to aerospace industry benchmarks for strength, corrosion resistance, and dimensional accuracy.
  • Quality assurance teams reference the standard for verifying compliance in both new production and maintenance operations.

• Component Procurement:

  • Procurement professionals rely on ISO 8575:2024 to specify tubing that matches international acceptance, reducing risk in materials sourcing and supplier management.

Related Standards

• ISO 8574: Specifies qualification tests for bent tubes in aerospace hydraulic systems, ensuring performance integrity after tube forming.
• ISO 6771: Defines pressure and temperature classes for aerospace fluid systems and components, directly referenced for compatibility in ISO 8575.
• ISO 2964: Establishes metric dimensions for tubing-important for aligning with the metric conversion aspects within ISO 8575.
• Material Standards: The standard references popular specifications for materials, such as AMS 5566 (Stainless Steel), AMS 4941 (Titanium), and EN 2070 (Aluminium).

Practical Value

Adherence to ISO 8575:2024 helps organizations achieve:

• Enhanced safety and reliability in aerospace hydraulic fluid systems.
• Streamlined global supply chain management, minimizing compatibility issues.
• Simplified compliance and certification processes for aerospace components.
• Consistent performance and service life of hydraulic system tubing under demanding aerospace conditions.

A diligent application of ISO 8575:2024 supports optimized system design, efficient manufacturing, and robust quality control, contributing directly to the airworthiness and maintenance efficiency of aerospace vehicles.