ISO 15875-2:2025

Overview

ISO 15875-2:2025 specifies requirements and test parameters for crosslinked polyethylene (PE‑X) pipes used in hot and cold water installations inside buildings. It covers PE‑X pipes with and without a barrier layer intended for domestic water and heating systems under the design pressures and temperatures defined by application class (see ISO 15875‑1:2025, Table 1). The standard is part of the ISO 15875 series and is intended to be used together with ISO 15875‑3 (fittings) and ISO 15875‑5 (joint performance).

Key topics and technical requirements

• Scope and applicability: Pipes for conveyance of water (whether or not for human consumption) and for heating systems; intended connections to ISO 15875‑3 fittings and joints conforming to ISO 15875‑5.
• Materials: Specifications for PE‑X pipe material and acceptance criteria for degree of crosslinking; inclusion of new crosslinking method PE‑Xe (UV light initiated crosslinking).
• Barrier layers: Requirements and thermal stability tests for barrier, adhesive and outer layer materials where applicable.
• Geometrical characteristics: Outside diameter and wall‑thickness requirements extended up to 250 mm; dimensional options for pipes with integrated or overlaid barrier layers.
• Mechanical and endurance tests: Defined test parameters for resistance to internal pressure (including new parameters at 20 °C / 22 h and 95 °C / 2 500 h), tensile and other mechanical characteristics.
• Physical and chemical: Opacity, oxygen permeability and influence on water intended for human consumption.
• Marking and documentation: Minimum marking requirements and test result interchangeability rules.
• Normative test methods and annexes: Includes test parameter definitions, derivation of S values and procedures to prove thermal stability (Annexes A–C).

Applications and who uses it

ISO 15875-2:2025 is used by:

• Manufacturers of PE‑X pipe systems to certify product design and testing.
• Testing laboratories to perform standardized mechanical, thermal and barrier tests.
• Specifiers, architects and MEP engineers selecting piping systems for domestic hot/cold water and heating applications.
• Installers and contractors for compliance and compatibility checks with fittings and jointing methods.
• Authorities and compliance bodies verifying fitness‑for‑purpose and safety for potable water installations.

Related standards

• ISO 15875‑1:2025 (general requirements and application classes)
• ISO 15875‑3 (fittings)
• ISO 15875‑5 (joint performance)
• ISO/TS 15875‑7 (conformity guidance)
• Other piping series referenced: ISO 15874, ISO 15876, ISO 15877, ISO 21003, ISO 22391

This standard is essential for ensuring consistent PE‑X pipe performance, reliable joint compatibility, and regulatory compliance in modern water and heating installations.