Fluid Systems Standards Summary - October 2025

Looking back at October 2025, professionals in the field of Fluid Systems witnessed the release of five notable standards that reflect both consolidation and innovation in piping system technologies. This month's suite of standards concentrated on the evolving landscape of polyethylene materials, an integrated approach to crosslinked polyethylene piping systems, and the refinement of specifications for underground drainage networks. For practitioners and decision-makers, a thorough understanding of these developments is essential for ensuring quality, safety, and regulatory compliance in modern fluid management projects. This article provides a comprehensive retrospective analysis of the standards released, offering insights into their broader significance, application, and practical adoption within the industry.

Monthly Overview: October 2025

The standardization activity in Fluid Systems during October 2025 highlighted a distinct shift towards harmonization, detailed material evaluation, and life-cycle optimization for piping systems. The month’s releases included a technically revised test method for slow crack growth resistance in polyethylene (PE), a cohesive update to the ISO 15875 series on PE-X piping for hot and cold water systems (covering general, pipe, and fittings requirements), and a comprehensive CEN standard for structured-wall pipes in non-pressure underground sewerage systems. Compared to previous months, October 2025 demonstrated increased alignment between international and European approaches, with standards showing heightened attention to durability, modular specification structures, and sustainability (e.g., provisions for recyclates and material characterization). This coordinated effort suggests the industry is prioritizing modular system integration and resilience against long-term mechanical and environmental stresses in both above-ground and buried applications.

Standards Published This Month

ISO 18488:2025 - Polyethylene (PE) materials for piping systems - Determination of strain hardening modulus in relation to slow crack growth - Test method

Polyethylene (PE) materials for piping systems — Determination of strain hardening modulus in relation to slow crack growth — Test method

ISO 18488:2025 introduces a robust methodology for assessing the resistance of polyethylene materials to slow crack growth via measurement of the strain hardening modulus. The standard details a tensile test protocol, relying on compression-moulded specimens and the analysis of true stress versus draw ratio curves, applicable regardless of PE manufacturing method, comonomer, or catalyst type. Its revised content refines the test definition, incorporates updated sample preparation and data reporting requirements, and enhances precision in apparatus calibration.

This technical revision is pivotal for manufacturers, laboratory personnel, and quality managers engaged in the qualification of PE pipe and fitting materials, particularly in water and gas distribution, where failure resistance is mission-critical. The adoption of this standard helps harmonize crack growth resistance evaluation, streamlining global procurement and compliance processes.

Key highlights:

• Revised strain hardening modulus definition and measurement protocol
• Broader acceptance of regrind PE and updated guidance on specimen preparation
• Direct alignment with other PE product standards and testing methods

Access the full standard:View ISO 18488:2025 on iTeh Standards

ISO 15875-1:2025 - Plastics piping systems for hot and cold water installations - Crosslinked polyethylene (PE-X) - Part 1: General

Plastics piping systems for hot and cold water installations — Crosslinked polyethylene (PE-X) — Part 1: General

The updated ISO 15875-1:2025 articulates the overarching requirements for PE-X piping systems in hot and cold water applications, encompassing both domestic and heating settings. The standard defines system scope, applicable service conditions (design pressures and temperature classes), and general terminologies, serving as the foundation for the series. It provides the structural framework for the performance and compatibility requirements detailed in Parts 2, 3, and 5, emphasizing the system-level approach to testing and installation.

Targeting manufacturers, specifiers, and building engineers, this updated edition reflects developments in piping system conceptualization, enhanced test parameter definitions, and clarified terminology. It encourages system-level thinking, moving beyond individual component compliance to holistic assurance of system integrity and service life.

Key highlights:

• Updated definitions of piping system structure and component integration
• Explicit classification of service condition classes and design pressures
• Foundation for interoperable standards across the PE-X system lifecycle

Access the full standard:View ISO 15875-1:2025 on iTeh Standards

ISO 15875-2:2025 - Plastics piping systems for hot and cold water installations - Crosslinked polyethylene (PE-X) - Part 2: Pipes

Plastics piping systems for hot and cold water installations — Crosslinked polyethylene (PE-X) — Part 2: Pipes

ISO 15875-2:2025 delineates detailed specifications and test methods for PE-X pipes designed for hot and cold water use in buildings, either for potable water or heating circuits. The revision expands upon geometrical requirements—covering dimensions, tolerances, and construction for both plain and barrier-layered pipes—and integrates updated testing for internal pressure, crosslinking, and thermal stability across a broadened size range (now up to 250 mm). This part not only addresses pipe material and oxygen permeability but also prescribes construction standards for compatibility with fittings and overall system performance.

Intended for pipe manufacturers, system designers, and certification bodies, the revised standard advances clarity on the use of barrier layers, inclusion of recyclate, and the modular integration of pipes and joints. Its rigor ensures reliable system lifecycle performance, aligning water system installers’ and regulators' expectations across diverse markets.

Key highlights:

• Expanded pipe size range and inclusion of barrier-layer constructions
• New and stricter thermal stability and internal pressure testing protocols
• Enhanced clarity on recyclate usage, construction standards, and dimensional integration

Access the full standard:View ISO 15875-2:2025 on iTeh Standards

ISO 15875-3:2025 - Plastics piping systems for hot and cold water installations - Crosslinked polyethylene (PE-X) - Part 3: Fittings

Plastics piping systems for hot and cold water installations — Crosslinked polyethylene (PE-X) — Part 3: Fittings

This third part of the ISO 15875 series focuses on the fittings used within PE-X piping systems, specifying geometrical, physical, chemical, and performance requirements for a variety of mechanical and electrofusion joint types. It mandates standardized material characteristics (for both PE-X and non-PE-X fittings), hydrostatic stress resistance, tightness, marking, and delineates compatibility requirements with pipes covered by Part 2. New in this edition are enhanced tests for stress corrosion, inclusion of auxiliary plastics materials, and the introduction of prolonged thermal stability testing.

The standard impacts manufacturers of fittings, system designers, and certification/certification laboratories, demanding stricter material qualification and cross-compatibility across modular piping networks. Its provisions for both plastic and metal fittings acknowledge the multidimensional nature of current water system installations.

Key highlights:

• Revised stress corrosion tests (2,500 h at 95°C), new definitions for plastics/auxiliary material compatibility
• Enhanced dimensional requirements and cross-standard marking rules
• Comprehensive mechanical and physical test requirements for a variety of fitting materials

Access the full standard:View ISO 15875-3:2025 on iTeh Standards

EN 13476-3:2025 - Plastics piping systems for non-pressure underground drains and sewers - Structured-wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) - Part 3: Specifications for pipes and fittings with smooth internal and profiled external surface and the system, Type B

Plastics piping systems for non-pressure underground drains and sewers — Structured-wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) — Part 3: Specifications for pipes and fittings with smooth internal and profiled external surface and the system, Type B

EN 13476-3:2025 delivers a robust European approach to specifying structured-wall pipes and fittings for non-pressure underground drainage and sewerage, with a focus on pipes composed of PVC-U, PP, or PE and featuring a smooth internal and profiled external (Type B) wall construction. The standard outlines system-level requirements, detailed material characteristics—including the use of recyclate—dimensions, jointing methods (including elastomeric and welded solutions), stiffness classes, and colour codes. Notably, the revision reflects the latest technical insights into ring flexibility, mechanical impact performance (including at sub-zero temperatures), and system marking.

End users include civil engineers, infrastructure project managers, and procurement specialists tasked with selecting and installing underground sewer and drainage systems. The document enables both national consistency and specification modularity, allowing tailored solutions that conform to diverse regulatory environments.

Key highlights:

• Comprehensive update of wall construction, test methods, and marking requirements
• Enhanced criteria for recyclate use and environmental performance
• Detailed jointing method descriptions (elastomeric, welded, fused) and system compatibility recommendations

Access the full standard:View EN 13476-3:2025 on iTeh Standards

Common Themes and Industry Trends

The October 2025 standards reveal several important sectoral trends:

• Holistic System Specification: Both the ISO 15875 series and EN 13476-3 focus on system-level compliance, emphasizing compatibility and performance of the entire assembly—not just isolated components.
• Durability and Life-Cycle Optimization: There is a clear movement towards specifying materials and test methods (e.g., strain hardening modulus, long-term pressure resistance, and enhanced corrosion testing) that extend operational lifetime under demanding service conditions.
• Material Versatility and Recyclability: Expanded guidance on the use of reworked materials and recyclates addresses sustainability imperatives without compromising system performance.
• Expanded Application Envelopes: Larger pipe size ranges and comprehensive performance classifications (e.g., in ISO 15875-2 and EN 13476-3) facilitate a broader spectrum of project needs in building and civil infrastructure.
• Enhanced Test Protocols: Stricter, standardized test requirements—especially for slow crack growth, hydrostatic stress and impact resistance—reflect heightened reliability expectations.

Compliance and Implementation Considerations

Organizations affected by these standards will need to adopt an integrative and forward-looking approach to compliance:

1. System Review: Review current piping systems and underground infrastructure against the new requirements for materials, testing, and marking.
2. Training and Quality Assurance: Ensure laboratory and field staff are familiar with test protocols for slow crack growth (ISO 18488), hydrostatic stress, and fitting compatibility. QA programs should be updated to reflect revised and new test stipulations and marking requirements.
3. Procurement: Target products and suppliers that are able to deliver fully compliant modular systems, covering pipes, fittings, and jointing elements in accordance with ISO 15875 and EN 13476-3 standards.
4. Timeline: Pay attention to the national adoption timelines (for CEN standards) and ensure procurement/installation cycles align with withdrawal of superseded standards (noted in EN 13476-3 for example).
5. Technical Resources: Leverage the detailed test method references and guidance documents included within these standards when specifying or assessing new systems.

Conclusion: Key Takeaways from October 2025

The successful navigation of October 2025’s standards releases in Fluid Systems is central to strategic planning for all stakeholders in piping and drainage infrastructure. The spotlight on enhanced PE material qualification, iterative series approaches to system definition, and integrated European requirements for underground sewerage networks signals a future in which system durability, sustainability, and modular specification are increasingly non-negotiable. Industry professionals are encouraged to:

• Prioritize adoption of updated testing and performance methods in both new projects and maintenance planning
• Embed system-level compliance into procurement, design, and installation workflows
• Continually monitor revisions within modular standard series (such as ISO 15875) to synchronize project documentation and certification

Staying abreast of these standards will position organizations at the forefront of safe, efficient, and future-ready fluid system management. Explore the linked standards in detail at iTeh Standards to ensure your operations align with the latest best practices and regulatory expectations.