Overview
ISO 4435:2003 - "Plastics piping systems for non-pressure underground drainage and sewerage - Unplasticized poly(vinyl chloride) (PVC‑U)" - sets requirements for PVC‑U pipes, fittings and piping systems used for non‑pressure underground drainage and sewerage (soil, domestic/industrial waste and surface water). The standard covers buried pipework (not piping buried inside building structures) and applies to PVC‑U pipes with or without integral sockets. It specifies material, geometrical, mechanical and performance requirements and the test parameters for conformity verification.
Key topics and technical requirements
- Material requirements
- Raw material must be PVC‑U with required additives; recommended guidance for use of non‑virgin material refers to EN 1401‑1.
- Minimum PVC content: ≥ 80% by mass for pipes, ≥ 85% for injection‑moulded fittings (or determined by EN 1905).
- Mechanical and ageing tests
- Pipe material: resistance to internal pressure - no failure during 1 000 h at 60 °C under specified circumferential stress (see EN 921).
- Fitting material: similar long‑term pressure test at specified hoop stress and dimensions.
- Geometrical characteristics
- Defines nominal outside diameters, nominal sizes (DN/OD), and acceptable out‑of‑roundness (≤ 0.024 × d_n).
- Wall‑thickness classes (SDR / SN series) and minimum wall thickness values for each nominal size.
- Chamfer requirements: chamfer angle 15°–45°, and remaining end wall thickness ≥ one‑third of e_min.
- Jointing and sealing
- Requirements for elastomeric ring‑seal sockets and spigots, sealing ring retention and leaktightness testing (see EN 1277, EN 1053).
- Other topics
- Surface finish, dimensional tolerances (ISO 3126), marking, adhesives, and test methods for impact, thermal and chemical resistance (references such as EN 580, EN 727, EN 743).
Applications
- Design, manufacture and quality control of buried non‑pressure drainage and sewerage systems using PVC‑U.
- Specification and procurement documentation for civil works, municipal drainage, stormwater conveyance and sewer networks.
- Test labs and conformity assessment bodies for product type‑testing and certification.
- Basis for installation guidance and component selection where long‑term chemical/temperature resistance and joint leaktightness are critical.
Who uses ISO 4435:2003
- PVC‑U pipe and fitting manufacturers
- Civil and environmental engineers
- Installers and contractors for underground drainage/sewerage
- Specifiers, procurement officers and regulators
- Testing laboratories and certification bodies
Related standards
Key normative references used in ISO 4435:2003 include ISO 3126 (dimensions), EN 1401‑1 (use of reprocessed material), EN 921 (resistance to internal pressure), EN 1277 and EN 1053 (joint leaktightness), EN 1905 (PVC content) and test methods for impact, thermal and chemical behaviour.
Keywords: ISO 4435:2003, PVC‑U, unplasticized polyvinyl chloride, non‑pressure underground drainage, sewerage, buried pipework, pipes and fittings, sealing rings, wall thickness, standards for drainage systems.