SIST EN ISO 15875-3:2026 PDF

Overview

EN ISO 15875-3:2025 - "Plastics piping systems for hot and cold water installations - Crosslinked polyethylene (PE‑X) - Part 3: Fittings" is a CEN-adopted European version of ISO 15875-3:2025. It specifies the characteristics, test parameters and requirements for fittings intended for PE‑X piping systems used in building hot and cold water installations (including potable water and heating systems). The standard covers fittings made from PE‑X, other plastics, or non‑plastic materials, and applies to mechanical and electrofusion fittings that connect to pipes conforming to ISO 15875-2 with joints meeting ISO 15875-5.

Key topics and requirements

• Scope and application classes: Defines intended use for domestic water and heating systems and references design pressures and temperatures per the ISO 15875 series.
• Material characteristics: Requirements for PE‑X bodies, auxiliary plastic parts, and metallic materials; consideration of influence on water intended for human consumption.
• Geometrical and dimensional requirements: Socket and metallic fitting dimensions, nominal diameters, threads and angles; Annex A gives dimensional requirements for metallic fittings.
• Mechanical performance: Strength, hydrostatic stress resistance and mechanical test protocols for fittings made from PE‑X and other plastics.
• Physical and chemical tests: Thermal stability, degree of crosslinking, melt flow rate for plastics; resistance to stress corrosion and dezincification for copper alloys.
• Sealing and joint integrity: Requirements for sealing elements and verification of joints consistent with ISO 15875-5.
• Marking and traceability: Minimum marking requirements and information to be provided on products for compliance and identification.
• Test methods and parameters: Standardised test parameters to ensure interchangeability and performance validation.

Practical applications and users

Who uses EN ISO 15875-3:2025:

• Manufacturers of PE‑X fittings and system components - for product design, testing and CE/national compliance.
• Product engineers and R&D - to select materials and validate mechanical/chemical performance.
• Test laboratories and certification bodies - to perform the standardised tests and report results.
• Specifiers, architects and consultants - to choose compliant fittings for potable water and heating systems.
• Installers, procurement and facility managers - to verify product marking, compatibility with ISO 15875-2 pipes and joint requirements (ISO 15875-5).

Practical benefits:

• Ensures safety, reliability and compatibility of fittings in domestic and heating installations.
• Facilitates harmonised testing and market acceptance across CEN member states.
• Supports potable water safety by specifying material influence and corrosion resistance requirements.

Related standards

• ISO 15875-1 - general principles and application classes (referenced for design pressures/temperatures)
• ISO 15875-2 - requirements for PE‑X pipes
• ISO 15875-5 - requirements for joints (compatibility with fittings)
• Annex B of EN ISO 15875-3 lists ISO standards for plastics materials used in hot and cold applications.