Overview
EN ISO 16138:2006 - Industrial valves - Diaphragm valves of thermoplastics materials (ISO 16138:2006) specifies requirements for the design, functional characteristics, manufacture and testing of diaphragm valves made from thermoplastic materials. The standard covers valves intended for isolating and control service in industrial pipe systems (hand- or power-operated), across a defined range of nominal sizes and pressure classes, with a design temperature window from −40 °C to +120 °C and a reference service life of 25 years.
Key keywords: EN ISO 16138, ISO 16138:2006, diaphragm valves, thermoplastics, industrial valves, pressure/temperature rating, DN sizes, PN classes, valve testing, PED compliance.
Key topics & technical requirements
- Scope and applicability: Valves for industrial pipe systems irrespective of application or conveyed fluid; includes water systems (with caveats for potable water).
- Size and pressure ranges: Covers DN 8 to DN 250 and pressure designations PN 6, PN 10, PN 16 and Class 150.
- Design and materials: Requirements for valve body geometry, internal trim and thermoplastic materials suitable for the rated pressures and temperatures.
- Pressure/temperature rating: Defines PMA (allowable maximum operating pressure) across the specified temperature range and includes rating factors for temperature adjustments.
- Operation and functional characteristics: Requirements for manual or powered operation, torque/fatigue considerations, and functional performance.
- Manufacture and traceability: Production controls, marking, documentation and traceability of pressure-bearing parts.
- Testing: Initial type tests and pressure tests, test documentation and acceptance criteria aligned with referenced valve test methods.
- Marking & storage: Requirements for marking, preparation for storage and transport, and declaration of compliance.
- Regulatory linkage: Informative Annex ZA maps key clauses of the standard to EU Directive 97/23/EC (PED), giving a presumption of conformity within scope.
Applications & who uses it
- Valve manufacturers and designers specifying thermoplastic diaphragm valve construction and testing.
- Process, chemical, water-treatment and wastewater engineers selecting valves for corrosive or chemically aggressive services.
- Procurement teams and compliance officers assessing vendor conformity and CE/PED requirements.
- Maintenance and inspection teams relying on standard testing and marking for lifecycle planning (25-year design life).
Related standards
Standards referenced within EN ISO 16138 include (non-exhaustive): EN 12266-1 (valve testing), EN 558 (face-to-face dimensions), EN 1267 (flow resistance), ISO 8233 / ISO 8659 (torque/fatigue tests), and material/system standards such as ISO 10931, ISO 15493, ISO 15494.
This standard is essential when specifying, manufacturing or certifying diaphragm valves made of thermoplastics to ensure safe, traceable, and compliant installations.
