Overview
ISO 22391-3:2009/Amd 2:2021 is an important amendment to the international standard covering plastics piping systems for hot and cold water installations using Polyethylene of Raised Temperature resistance (PE-RT). Specifically, this document focuses on Part 3: Fittings, providing updated requirements for fittings made from PE-RT and compatible metallic materials such as copper alloys and stainless steel.
This amendment enhances material definitions, dimensional tolerances, and testing procedures to ensure the durability, safety, and performance of piping fittings under various temperature and pressure conditions. It is a key resource for manufacturers, designers, and engineers involved in hot and cold water plumbing systems.
Key Topics
-
Scope of Fittings: The document details fittings types including compression fittings, radial and axial press fittings, and push-fit fittings. It defines the mechanisms by which joints are formed and sealed, emphasizing the importance of internal pipe supports and sealing elements.
-
Materials Standards:
- Plastic fittings use PE-RT compounds with restrictions on melt mass flow rate (MFR) variations after processing.
- Metallic fittings are limited to copper alloys or stainless steel alloys conforming to recognized standards. Requirements for corrosion resistance, specifically stress corrosion and dezincification resistance, are included to ensure long-term integrity.
-
Dimensional and Appearance Requirements:
- Plastic fittings must have smooth, clean surfaces free from defects.
- Metallic fittings must be free of residues, cracks, and sharp edges with strict wall thickness tolerances measured at designated points.
- Dimensional measurements must adhere to ISO 3126 (plastic) and ISO 2768-1 and ISO 22081 (metal fittings) for accuracy.
-
Testing and Quality Assurance:
- Tightness testing for cast alloy fittings involves compressed air at a minimum of 0.5 MPa to detect leaks.
- Corrosion resistance tests follow ISO 6957 for stress corrosion and ISO 6509-1 for dezincification when applicable.
-
New Terminology and Definitions:
- Clarifications on the types of fittings and their jointing methods support better understanding and implementation of installation practices.
Applications
ISO 22391-3:2009/Amd 2:2021 serves as a critical guideline for:
- Designing and manufacturing reliable piping fittings for both hot and cold potable water supply systems.
- Ensuring compliance with international and regional plumbing codes by standardizing materials and jointing methods.
- Facilitating quality control and certification processes in plastic and metal pipe fittings production.
- Supporting installation professionals by defining the characteristics and performance expectations for fittings to be used with PE-RT piping systems.
- Promoting safe and durable water installation networks in residential, commercial, and industrial buildings.
This standard supports sustainable plumbing practices by endorsing corrosion-resistant materials and robust testing methods that reduce failure rates and maintenance needs.
Related Standards
ISO 22391-3:2009/Amd 2:2021 complements other standards critical to plastics piping systems and metallic fittings, including:
- ISO 22391 series - covering PE-RT pipe systems, guidance on conformity, and installation practices.
- ISO 3126 - Plastics piping system dimensional measurement.
- ISO 2768-1 and ISO 22081 - For tolerances and geometrical product specifications of metallic components.
- ISO 6506-1 and ISO 6509-1 - Testing methods for metallic hardness and dezincification resistance.
- ISO 6957 - Stress corrosion resistance testing of copper alloys.
- CEN/TS 13388 and EN 1982 - Standards defining copper and copper alloy compositions.
- ISO 16143 and EN 10088 - Standards defining stainless steel corrosion-resistant products.
These related documents collectively establish comprehensive criteria for the manufacture, testing, and installation of plastic and metal fittings used in modern water installation systems worldwide.
Keywords: ISO 22391-3, PE-RT fittings, plastics piping systems, hot and cold water installations, polyethylene of raised temperature resistance, metallic fittings, copper alloys, stainless steel, compression fittings, radial press fittings, axial press fittings, push-fit fittings, corrosion resistance, piping dimensions, fitting testing, international plumbing standards.
Open preview (PDF)Plastics piping systems for hot and cold water installations — Polyethylene of raised temperature resistance (PE-RT) — Part 3: Fittings — Amendment 2
