ISO 15876-2:2017

Overview

ISO 15876-2:2017 specifies requirements for polybutene (PB) pipes used in piping systems for hot and cold water installations within buildings - including domestic water and heating systems. Part 2 of the ISO 15876 series focuses on the pipe product (geometry, material behaviour, testing and marking) and is intended to be used together with ISO 15876‑1 (general) and other parts for fittings, joints and system fitness-for-purpose.

Key technical topics and requirements

• Scope and applicability: Covers PB-1 pipes for conveyance of water (whether or not for human consumption) and for heating systems under the application classes and design pressures/temperatures defined in ISO 15876‑1. It does not apply where Td, Tmax or Tmal exceed values given in Part 1.
• Material types: Differentiates PB homopolymer (PB‑H) and PB random copolymer (PB‑R) (introduced in this edition) and requires pipe material to conform with ISO 15876‑1.
• Crystalline phase transition (ageing): PB pipes undergo a slow crystallization after extrusion. Minimum conditioning guidance: ~5 days for PB‑H and ~1 day for PB‑R at 23 °C before testing, unless accelerated ageing is used.
• Long‑term hydrostatic strength: Material evaluation by procedures such as ISO 9080 and internal pressure tests per ISO 1167‑1/2. Conformance demonstrated by comparing σ (hoop stress) vs time curves against reference lines for PB‑H and PB‑R; at least 97.5% of test points should lie on or above the reference.
• Geometrical and appearance requirements: Dimensions and tolerances per ISO 3126; surface finish, clean cuts, and opacity limits (opaque pipes ≤ 0.2% visible light transmission per ISO 7686).
• Test parameters and marking: Specifies test parameters for referenced methods and minimum marking requirements for traceability and correct selection by specifiers.
• Barrier layers: Applies to pipes with or without thin barrier layers; design stress requirements are met by the base PB polymer.

Practical applications and users

ISO 15876-2:2017 is used by:

• Pipe manufacturers for design, production and quality control of PB pipes.
• Testing laboratories for hydrostatic strength, dimensional and opacity testing.
• Specifiers, consulting engineers and architects selecting piping materials for domestic water and heating systems.
• Installers, building owners and authorities to ensure compliance with system requirements.
• Certification bodies assessing conformity with the ISO 15876 system.

The standard helps ensure safe, durable PB piping suitable for building water distribution and heating, while guiding selection of correct application class and compliance with national regulations.

Related standards

• ISO 15876‑1 (General)
• ISO 15876‑3 (Fittings)
• ISO 15876‑5 (Fitness for purpose)
• ISO/TS 15876‑7 (Conformity assessment guidance)
• Normative test references: ISO 9080, ISO 1167‑1/2, ISO 3126, ISO 7686, ISO 1133‑1.