Overview
ISO 6993-1:2006 specifies requirements for buried, high‑impact poly(vinyl chloride) (PVC‑HI) pipes used to convey gaseous fuels at a maximum operating pressure (MOP) of 1 bar (100 kPa) and an operating temperature range of 0 °C to +30 °C. It applies to pipes manufactured from the impact‑modified PVC materials PVC‑A, PVC‑CPE and PVC‑EPR and is intended for gases that do not contain concentrations of components likely to impair the pipe material.
Keywords: ISO 6993-1:2006, PVC-HI, buried piping systems, gaseous fuels, 1 bar, PVC-A, PVC-CPE, PVC-EPR.
Key Topics
- Scope and application: Buried piping systems for gaseous fuels with MOP up to 1 bar and service temperatures 0–30 °C.
- Materials: Requirements for PVC‑HI composition (impact modifier ≥ 7% by mass) and permitted additives.
- Long‑term strength (MRS): Material qualification based on long‑term hydrostatic strength testing (ISO 9080); the extrusion material shall have an MRS of at least 18 MPa.
- Thermal and chemical resistance:
- Vicat softening temperature ≥ 76 °C (ISO 2507).
- Resistance to gas constituents assessed per Annex A and clause 11.
- Physical and mechanical properties:
- Limits on contaminants and appearance (surface free of pits, blisters, voids).
- Minimum wall thickness (for handling and soil loads) - typically ≥ 2.0 mm for SDR series.
- Dimensional tolerances, mean outside diameter, out‑of‑roundness and SDR requirements per ISO 3126 and Table specifications.
- Testing and compliance:
- Tests for long‑term hydrostatic strength, resistance to external blows (Annex B / ISO 3127), longitudinal reversion (ISO 2505), UV/weathering, and specific marking requirements.
- Marking and documentation: Requirements for traceability and identification on manufactured pipes.
Applications and Who Uses It
ISO 6993-1 is used by:
- Pipe manufacturers and material suppliers to design and certify PVC‑HI pipes for buried gas distribution.
- Gas utilities and network designers selecting materials for low‑pressure buried mains and service lines (≤ 1 bar).
- Installers, contractors and specifiers who need to ensure conformity with international requirements for safety, durability and installation compatibility.
- Testing laboratories performing material qualification and compliance testing (MRS, Vicat, impact and gas‑constituent resistance).
Practical applications include low‑pressure natural gas distribution mains, service connections and other buried gas pipelines where PVC‑HI properties meet site gas composition and temperature constraints.
Related Standards
- Other parts of the ISO 6993 series: ISO 6993‑2, ISO 6993‑3, ISO 6993‑4 (fittings and code of practice).
- Referenced test standards: ISO 9080, ISO 3126, ISO 3127, ISO 2505, ISO 2507, ISO 9852, ISO 9969 - used for long‑term strength, dimensional, impact, thermal and chemical testing.
For manufacturers and operators working with buried PVC‑HI gas piping, ISO 6993‑1:2006 provides the material, dimensional and test framework needed to ensure safe, durable low‑pressure gas distribution systems.