ISO 9679:2006

Overview

ISO 9679:2006 - Aerospace - Clamps for fluid systems - Test methods defines standardized test procedures for the qualification and comparison of support and retention devices (clamps, blocks, grommets) used in aerospace fluid systems. It is intended to be cited by parts standards, procurement specifications, or other definition documents and ensures consistent verification of material properties, retention performance, vibration behavior and environmental compatibility.

Key topics and technical requirements

• Scope and test conditions: Tests are for device qualification only (not installation or service techniques). Unless otherwise specified, tests are at room temperature (25 ± 10 °C).
• Material tests
  • Ozone resistance: Non‑metallic materials tested per ISO 1431‑1 with an ozone concentration of 6 × 10‑6 by volume, 80% strain for 6 h at (40 ± 2) °C.
  • Flame resistance: Vertical burn test using a 10 mm burner, 38 mm blue flame (≥ 849 °C). Specimens preconditioned, flame applied 12 s; average burn time ≤ 15 s and dripping burn ≤ 5 s.
  • Insulation: Vulcanized rubber insulation assessed per ISO 2951 where applicable.
  • Ultraviolet resistance: Exterior plastics/elastomers tested per ISO 4892‑3 (fluorescent UV lamps).
  • Titanium compatibility: Clamps mounted on Ti‑3Al‑2.5V tubing, filled with hydraulic fluid, exposed to max service temperature for 12 days at 21 000 kPa (3 000 psi), then 20 days at 70 °C/95% RH; inspect for cracking/pitting (5–10× magnification).
• Tube support assembly tests
  • Preparation: Uses tube sizes 12 mm, 19 mm, 25 mm (Ti‑3Al‑2.5V tubing), specimens preconditioned before testing.
  • Retention test: Axial force measured by forcing tube 25 mm through assembly; no separation/delamination; forces must meet procurement spec.
  • Vibration and transmissibility: Assemblies mounted on vibration table, tubes 737 mm long with 305 mm support spacing and 64 mm overhangs. Simple harmonic sweep 50–500 Hz at 2g (logarithmic sweep, 5 min per cycle). Record resonances, compute transmissibility ratio, then dwell 30 min at worst resonance at 10g.
  • Post‑test inspection: Recheck retention, examine for cracks, wear, material degradation; tube wear allowed ≤ 5% of wall thickness.

Applications and users

ISO 9679:2006 is used by:

• Aerospace OEMs and Tier‑1/Tier‑2 suppliers qualifying clamps, blocks and grommets
• Design and test engineers validating support hardware for hydraulic, fuel, pneumatic and other fluid systems
• Quality, procurement and specification writers referencing consistent acceptance criteria
• Certification bodies and maintenance organizations assessing hardware durability and compatibility

Related standards

• ISO 1431‑1:2004 (ozone resistance)
• ISO 2951 (rubber insulation resistance)
• ISO 4892‑3 (UV exposure)

ISO 9679:2006 provides a practical, repeatable framework for verifying clamp performance and environmental compatibility in aerospace fluid installations, improving safety and supplier consistency.