Overview
ISO 24131-1:2023 specifies requirements and test methods for factory-applied polyurethane internal linings for ductile iron pipes (per ISO 2531, ISO 7186 and ISO 16631). The standard covers linings intended for the conveyance of raw water, potable water and sewage at operating temperatures up to 50 °C. It establishes technical and performance criteria, routine and performance test regimes, and quality assurance guidance for manufacturers and testing laboratories.
Key Topics
- Scope and definitions: Clear terms for polyurethane lining, cross-linkage, non-porosity (holiday testing), adhesion, minimum lining thickness, chalking and more.
- Technical requirements:
- Surface preparation: Clean, dry substrates; maintain surface temperature above dew point; manufacturer responsibility to demonstrate fitness-for-purpose.
- Surface roughness and appearance: Requirements for substrate profile and visual inspection criteria.
- Lining thickness and protection of pipe ends: Minimum thickness control and end/coating protection for spigots and sockets.
- Adhesion and cross-linkage: Pull-off adhesion tests and verification of cure chemistry.
- Non-porosity (holiday) testing: Electrical puncture testing to confirm continuity of the lining.
- Hardness and mechanical properties: Shore hardness, elongation at break, resistance to ovalization.
- Performance requirements:
- Abrasion and chemical resistance (specifically for sewage applications).
- Indirect impact resistance and resistance to hot water.
- Specific lining resistance (electrical surface resistance).
- Test methods:
- Routine tests for process control (e.g., thickness, adhesion, DSC, hardness, non-porosity).
- Performance tests required on material/process changes (e.g., abrasion, chemical, impact, hot water).
- Quality assurance and handling: Normative Annex A (quality assurance) and informative Annex B (handling, transport, storage).
Applications
ISO 24131-1:2023 is used to:
- Specify acceptance criteria in procurement and contract documents for lined ductile iron pipes.
- Guide manufacturers of ductile iron pipes and lining applicators on production control and factory testing.
- Support QA/QC teams and independent testing laboratories performing routine and performance tests.
- Inform engineers, water utilities, and consultants selecting linings for potable water, raw water and sewage pipelines.
Who benefits: pipe manufacturers, coating system suppliers, municipal utilities, civil/pipe engineers, contractors, and compliance auditors.
Related standards
Key referenced standards include:
Keywords: ISO 24131-1:2023, polyurethane lining, ductile iron pipes, internal protection, test methods, potable water lining, sewage pipe lining, factory applied lining.