Overview
ISO 12319:2006 - "Aerospace - 'P' (loop style) clamps - Procurement specification" defines procurement and quality-assurance requirements for 'P' (loop style) clamps used in aerospace fluid systems. The standard ensures clamps supplied to maintain the same performance and safety characteristics as those used during original qualification testing, especially where clamp failure could affect flight safety. ISO 12319:2006 covers material, configuration, dimensional and surface requirements, testing, inspection, marking and certification.
Key topics and technical requirements
- Scope and intent: Procurement specification for loop-style clamps used in aerospace fluid installations; ensures consistent quality and safety.
- Qualification and product approval: Manufacturer and product qualification via outside agency procedures; periodic requalification (samples every two years) to retain approval.
- Materials and configuration: Clamp materials and dimensional/mass requirements are defined by the applicable part/definition document; installation and mandrel tolerances are specified.
- Surface and marking: Requirements for workmanship, freedom from burrs and foreign material, surface treatments and identification (standard number, size, manufacturer/trademark).
- Performance tests:
- Vibration and transmissibility: Tested per ISO 9679; clamps must show no sheath/cushion deterioration, cracking or separation and maintain minimum retention.
- Retention (minimum axial force): Fixed clamps - 12 mm: 7.0 kg; 19 mm: 12.0 kg; 25 mm: 16.0 kg. Sliding clamps - between 0.46 kg and 4.5 kg if movement is required.
- Titanium compatibility: No cracking, pitting or abrasion of titanium tubes under test conditions.
- Ozone resistance: Required for elastomer sheathing/cushion (except EPDM); resistant to an ozone volume fraction of 6 × 10^-6 under 80% strain, per ISO 9679.
- Optional tests: Ultraviolet resistance (ISO 4892-3) and electrical insulation (ISO 2951) where required.
- Quality assurance and sampling: Contractual responsibility for inspection lies with the contractor unless specified otherwise; sampling based on ISO 2859-1 with defined AQLs for major/minor defects.
- Documentation: Certified test reports, part drawings (open/closed), cushion manufacturer and full identification required for qualification.
Applications and users
ISO 12319:2006 is used by:
- Aerospace manufacturers and OEMs specifying clamps for fluid systems.
- Component suppliers and contract manufacturers for procurement and qualification.
- Quality/inspection engineers and procurement specialists ensuring conformance.
- Certification/qualification agencies and MRO organizations verifying replacement parts.
Use cases include specification control for fuel, hydraulic and pneumatic line installations where clamp performance is critical to flight safety.
Related standards
- ISO 9679 - Clamps for fluid systems - Test methods (referenced for vibration, retention, titanium compatibility)
- ISO 2859-1 - Sampling procedures for inspection by attributes
- ISO 4892-3 - UV exposure test methods
- ISO 2951 - Insulation resistance for vulcanized rubber
- EN 9100 / EN 9133 - Aerospace quality systems and qualification procedures
Keywords: ISO 12319:2006, 'P' loop style clamps, aerospace clamps, procurement specification, aerospace fluid systems, clamp qualification, vibration transmissibility, retention values, ozone resistance, titanium compatibility.