Overview
ISO 8479:1986 specifies dimensional requirements for aerospace “Q” clamps (centre‑mounted clamps) used in fluid systems. The standard defines maximum and minimum envelope dimensions for clamps mounted with a bolt of nominal diameter 5 mm. It covers clamp types for a wide temperature range and provides the dimensional envelope (table 2) for nominal tube sizes from DN 3.2 up to DN 100. ISO 8479 is a dimensional envelope standard - it is not an interchangeability standard; tolerances and detailed features are defined in part drawings or product‑specific standards.
Key topics and requirements
- Clamp type and mounting: Centre‑mounted “Q” clamps, available as single‑block or multi‑component designs. Multi‑component clamps include a metallic support with a plastomer or elastomer cushion/sheathing.
- Bolt mounting: Dimensions are specified for clamps installed using a bolt with nominal diameter 5 mm.
- Dimensional envelope: Table 2 in the standard lists minimum and maximum dimensions (A, B, D, F, G, H, L) for nominal tube diameters DN 3.2 to DN 100. All dimensions apply with the tube assembled in the tightened clamp.
- Temperature classification: Clamps are classified into six types by intended service temperature ranges (from –55 °C up to +650 °C for type 6). Selection of clamp type should match the operating temperature.
- Usage limits: Clamps larger than DN 50 are not suitable for supporting tubing or hose assemblies; such larger sizes may be repurposed for supporting electrical cables, looms or other equipment.
- Not an interchangeability standard: The standard establishes the envelope and mounting locations; specific tolerances and interchangeability must be established in part standards or manufacturing drawings.
- Reference standard: ISO 6771 (pressure and temperature classifications for aerospace fluid systems) is referenced.
Applications
- Design and specification of clamp components for aircraft fluid systems (hydraulic, fuel, oil lines).
- Development of component drawings and part standards that require a defined dimensional envelope.
- Procurement and quality inspection to verify clamp dimensions and mounting compatibility.
- Routing and support planning for rigid tubing and hose assemblies in aerospace platforms.
- Aerospace design and mechanical engineers
- Aircraft systems integrators and installation technicians
- Manufacturers and suppliers of clamps, tubing supports and cushions
- Quality assurance, procurement and regulatory teams involved in aerospace components
Related standards
- ISO 6771 - Aerospace construction: fluid systems and components - pressure and temperature classifications
Keywords: ISO 8479, “Q” clamps, centre‑mounted clamps, aerospace, fluid systems, clamp dimensions, DN sizes, tubing support, hose assemblies, temperature classification.