ISO 15875-3:2003

Overview

ISO 15875-3:2003 defines requirements for fittings used with crosslinked polyethylene (PE‑X) piping systems for hot and cold water installations inside buildings. It is Part 3 of the ISO 15875 series and works together with Parts 1 (General), 2 (Pipes), 5 (Fitness for purpose) and 7 (Conformity guidance). The standard covers fittings intended for domestic water (potable or non‑potable) and heating systems, across the application classes and design pressure classes defined in ISO 15875‑1. It also specifies parameters for the referenced test methods.

Key topics

• Scope and applicability
  • Fittings for PE‑X systems used in hot and cold water and heating installations.
  • Applies to mechanical fittings, electrofusion fittings and fittings with incorporated inserts.
  • Not applicable when design or malfunction temperatures exceed the limits given in ISO 15875‑1.
• Materials
  • Requirements for fittings made from PE‑X (both identical and non‑identical to pipe material).
  • Requirements for fittings made from other plastics and metallic materials.
  • Consideration of influence on water intended for human consumption.
• Geometry and dimensions
  • Nominal diameters, angles and thread forms.
  • Socket dimensions for electrofusion fittings and dimensions for metallic fittings.
• Mechanical, physical and chemical properties
  • Mechanical performance requirements for different fitting material combinations.
  • Long‑term hydrostatic strength and resistance to internal pressure addressed via referenced test methods.
• Sealing and joints
  • Requirements for elastomeric sealing elements and joint types (compression, crimped, flanged, flat seat union).
  • Compatibility with joint performance criteria in ISO 15875‑5.
• Performance, testing and marking
  • Test parameter specifications (referenced normative standards).
  • Minimum marking requirements for traceability and conformity.

Applications

ISO 15875‑3:2003 is used for:

• Specification and design of building plumbing and heating systems using PE‑X piping.
• Product design, testing and quality control by manufacturers of PE‑X fittings (mechanical, electrofusion, insert fittings).
• Assessment, certification and conformity testing by testing laboratories and certification bodies.
• Procurement, specification and compliance checks by project engineers, building services designers, contractors and regulators.

Related standards

• ISO 15875‑1 (General), ISO 15875‑2 (Pipes), ISO 15875‑5 (Fitness for purpose), ISO 15875‑7 (Conformity guidance).
• Various normative references cited for test methods and materials (e.g., EN ISO 3126, EN ISO 9080).

Keywords: ISO 15875-3:2003, PE‑X fittings, crosslinked polyethylene, plumbing standard, electrofusion fittings, mechanical fittings, hot and cold water installations, piping system fittings.