Overview
ISO 16486-2:2024 specifies the physical and mechanical properties of pipes made from unplasticized polyamide (PA‑U) intended for buried plastics piping systems that convey gaseous fuels. Part 2 of the ISO 16486 series focuses on pipes used in PA‑U systems with fusion jointing and mechanical jointing, and defines dimensional characteristics, test parameters and marking requirements for pipes that are typically joined by mechanical, electrofusion or butt‑fusion techniques.
Key topics and requirements
- Material and compound: Pipes must be manufactured from PA‑U compound in accordance with ISO 16486‑1 and produced from virgin material only (no rework/recyclate).
- Appearance and colour: Internal and external surfaces shall be smooth and defect‑free; colours required are yellow or black (black pipes may carry yellow/orange stripes by preference).
- Fusion compatibility: PA‑U11 and PA‑U12 are not fusion compatible with each other or with other polymers - PA‑U11 only fuses with PA‑U11, PA‑U12 only with PA‑U12.
- Geometrical characteristics: Specifies mean outside diameter, out‑of‑roundness and tolerances for a range of nominal sizes (typical sizes covered from 16 mm up to larger diameters). Dimensional measurement is specified per ISO 3126 at (23 ± 2) °C after conditioning.
- Wall thickness and tolerances: Minimum wall thickness and point tolerances are defined to ensure structural integrity for buried gas operation.
- Mechanical and physical testing: Conditioning and performance requirements reference standard test methods (e.g., ISO 1167, ISO 2505, ISO 13477, ISO 13479, ISO 6259). Test parameter settings for these methods are specified.
- Special techniques & annexes: Annex A covers the squeeze‑off technique; Annex B provides water uptake examples as a function of sample thickness.
- Marking: Requirements for pipe marking (identification, size, material, etc.) to support traceability and safe installation.
Practical applications and users
ISO 16486-2:2024 is used by:
- Pipe manufacturers to design and certify PA‑U pipes for buried gas distribution.
- Gas utilities and network operators specifying materials for new or replacement buried mains and service lines.
- Contractors and fusion operators selecting pipes compatible with mechanical, electrofusion or butt fusion joining.
- Testing laboratories and conformity assessors performing mechanical/physical tests and dimensional verification.
- Specifiers and standards authors aligning project specifications with international requirements.
Typical applications include buried distribution mains, service lines for natural gas and blends, and systems evaluated for hydrogen admixtures (see ISO 16486‑1 for hydrogen suitability information).
Related standards
- ISO 16486‑1, ISO 16486‑3, ISO 16486‑4, ISO 16486‑5, ISO 16486‑6 (installation guidance), ISO/TS 16486‑7/‑8
- Referenced test standards: ISO 291, ISO 3126, ISO 1167, ISO 2505, ISO 13477, ISO 13479, ISO 6259, ISO 11922‑1, ISO 307, ISO 1133‑2
Keywords: ISO 16486-2:2024, PA‑U pipes, unplasticized polyamide, plastics piping systems, gaseous fuels, fusion jointing, mechanical jointing, buried gas pipelines.