Overview
ISO 22436:2018 - titled Aerospace series - Pipe coupling 8°30′ - Thread end - Geometric configuration - defines the geometric characteristics of the thread end for 8°30′ pipe couplings used in aerospace fluid systems. The standard applies to couplings rated for nominal pressure up to 28 000 kPa and establishes dimensional, form and surface requirements to ensure interchangeability, sealing performance and manufacturing consistency.
Key topics
- Scope & units: All dimensions are specified in millimetres and apply to aerospace pipe couplings with 8°30′ mating geometry.
- Forms and configuration: Detailed geometric definitions are provided for Form B and Forms C to L. Figures 1–10 and Tables 1–2 in the standard supply the dimensioning and tolerance data for each form.
- Dimensions & tolerances: Dimensional requirements and tolerances are given for thread interfaces and sealing faces; these tolerances apply before lubrication.
- Surface roughness: Surface finish requirements for threads and sealing faces are specified (see Figures 1–10). The O‑ring sealing groove shall not contain any radial tool marks, ensuring reliable seal seating.
- Lubrication: Threads and sealing faces are to be lubricated in accordance with EN 2491 (molybdenum disulphide dry lubricants) as referenced.
- Thread series: References to MJ threads (per ISO 5855‑3) and nut tolerance guidance (ISO 8788) are included where applicable.
- Designation: The standard includes rules for designation of the thread-end configuration to support procurement and documentation.
Applications
- Aerospace component designers specifying pipe fittings and couplings for hydraulic and pneumatic systems.
- Manufacturers and CNC programmers producing couplings and fittings to consistent geometric and surface standards.
- Quality engineers and inspectors verifying acceptance criteria, dimensions and surface finishes.
- Maintenance and procurement teams ensuring replacement parts and suppliers conform to the correct ISO 22436:2018 configuration and pressure rating.
- Optimal for use where high-pressure aerospace fluid integrity and interchangeability are required.
Related standards
- EN 2491 - Molybdenum disulphide dry lubricants - coating methods (lubrication requirement).
- ISO 5855‑3 - Aerospace MJ threads - limit dimensions for fittings for fluid systems (thread limits).
- ISO 8788 - Aerospace nuts, metric - tolerances of form and position (nut tolerances).
ISO 22436:2018 is essential for anyone involved in the design, manufacture, inspection or procurement of 8°30′ aerospace pipe couplings, providing the geometric configuration and surface requirements needed for reliable, high‑pressure fluid system performance.