Overview
EN ISO 22391-3:2009/A1:2020 is an amendment to the European adoption of ISO 22391-3:2009, the part of the ISO 22391 series that covers fittings for PE-RT (polyethylene of raised temperature resistance) piping systems used in hot and cold water installations. Published by CEN in December 2020, this Amendment 1 specifically updates dimensional requirements for electrofusion socket fittings, clarifying socket diameters, fusion-zone depths and penetration lengths for a range of nominal pipe sizes.
Key topics and technical requirements
- Electrofusion socket dimensions: The amendment replaces Table 6 in the original standard with revised socket dimensions for electrofusion fittings, given in millimetres for nominal diameters from 16 mm up to 250 mm.
- Fusion zone depths and penetration lengths: Updated minimum and maximum values for the depth of penetration of the fusion zone and the nominal length of the fusion zone are specified to ensure consistent weld quality.
- Dimensional tolerance note: For systems that use spigot trimming, the standard permits smaller values for socket diameter (D) when they conform to the manufacturer’s specification.
- Standards governance: Prepared by ISO/TC 138 in collaboration with CEN/TC 155, and endorsed for national implementation across CEN member bodies.
Applications
This amendment is directly applicable to design, manufacture, installation and quality control of PE-RT piping systems for domestic and commercial hot and cold water supply, where reliable electrofusion connections are required. Typical applications include:
- Plumbing and sanitary water distribution
- Underfloor heating and radiant heating systems using PE-RT pipework
- Prefabricated plumbing modules and mechanical room assemblies
- Production and testing of electrofusion fittings and fusion equipment
Who should use this standard
- Manufacturers of PE-RT pipes and electrofusion fittings (to ensure product dimensional compliance)
- Plumbing system designers and consulting engineers (to specify compatible fittings and jointing methods)
- Installers and contractors performing electrofusion welding and commissioning of water systems
- Regulatory bodies and certification labs verifying compliance and performing type testing
Related standards and keywords
Related documents: other parts of the ISO 22391 series, ISO/TC 138 and CEN/TC 155 guidance.
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For exact dimension tables and implementation details, consult the official EN ISO 22391-3:2009/A1:2020 document.