Overview
EN ISO 21003-2:2008 (ISO 21003-2:2008) specifies requirements for pipes used in multilayer piping systems for hot and cold water installations inside buildings. It covers the characteristics and test parameters for multilayer pipes intended for domestic water and heating systems under specified design pressures and temperatures. EN ISO 21003-2 is a reference product standard and is intended to be used together with the other parts of ISO 21003 (system general requirements, fittings, fitness-for-purpose, and conformity guidance).
Keywords: multilayer piping systems, hot and cold water installations, EN ISO 21003-2, ISO 21003-2, multilayer pipes, building plumbing standards.
Key Topics
- Scope and applicability: Pipes for conveying water inside buildings (domestic and heating systems). Limits on design temperature and malfunction temperature are referenced to ISO 21003-1 (application classes).
- Materials: Stress-bearing polymeric layers permitted include PB, PE-RT, PE‑X, PP and PVC‑C. PE‑X used must be fully crosslinked and comply with the relevant reference product standard (e.g., ISO 15875).
- Construction & geometry: Requirements for multilayer construction, layer arrangement and dimensional tolerances.
- Pressure strength: Long-term pressure strength and design pressure concepts are specified (including parameters and test conditions).
- Thermal durability: Tests and criteria for thermal ageing of pipe layers, including oven-ageing and long-term elongation assessments.
- Weld line strength & delamination: Strength requirements for weld lines in certain multilayer constructions and tests for interlayer delamination.
- Oxygen permeability: Requirements where oxygen diffusion is a concern (e.g., heating systems).
- Physical/chemical characteristics & marking: Tests for material properties, effects on water quality, and mandatory product markings.
- Test parameters: Specific test parameters for methods referenced in the standard (so laboratories and manufacturers run consistent tests).
Applications
- Residential and commercial plumbing for hot and cold potable water distribution.
- Heating systems where multilayer pipes are used in underfloor heating or radiator circuits.
- Product development, quality control and certification by pipe manufacturers and testing laboratories.
- Specification and procurement when designers and building engineers select compliant multilayer piping systems.
Who uses this standard
- Pipe and fitting manufacturers
- Plumbing designers and specifiers
- Installation contractors and system integrators
- Testing laboratories, conformity assessment bodies and national standards organizations
- Regulatory authorities and building code writers evaluating materials for water contact
Related standards
EN ISO 21003-2 helps ensure consistent safety, durability and performance of multilayer piping systems used inside buildings - a critical reference for anyone specifying, producing or testing modern plumbing systems.
