ISO 16138:2006

Overview

ISO 16138:2006 - Industrial valves - Diaphragm valves of thermoplastics materials - defines requirements for the design, functional characteristics, manufacture and testing of diaphragm valves made from thermoplastic materials. It covers valves for isolating and control service (hand- or power-operated) for industrial pipe systems, rated for a service life of 25 years and a working temperature range from −40 °C to +120 °C. The standard applies to nominal sizes DN 8–DN 250 and pressure classes PN 6, PN 10, PN 16 and Class 150.

Key topics and technical requirements

• Design requirements
  • Diaphragm separating bonnet and functional parts from the process fluid.
  • Bonnet sealing at the diaphragm/body interface; compressor and spindle that press the diaphragm against the weir.
  • Valve obturation designed for both flow directions.
• End connections
  • Supported end types include butt-fusion, spigot (cementing/welding), socket (electrofusion/heated tool/cementing), flanged, threaded and union ends.
• Materials
  • Body materials: ABS, PE, PP, PVC-C, PVC-U, PVDF (selection per ISO 15493 / ISO 15494 / ISO 10931).
  • Trim, diaphragm and other internal components: manufacturer responsibility; must meet mechanical integrity and pass specified tests.
• Pressure/temperature (p/t) rating
  • PMA (allowable maximum operating pressure) derived using a rating factor f: PMA = f × PN (bar) or PMA = f × Class (psi).
  • ISO 16138 provides minimum rating factors for body materials over the service temperature range; manufacturers must declare the p/t rating for each valve type and material.
• Testing and conformity
  • Initial type tests and documentation of test results are specified (see Clause 5).
  • Requirements for manufacture, marking, storage, transport and declaration of compliance are included.

Applications and users

• Practical applications: chemical processing, water treatment, drainage/sewerage, industrial fluid handling and any industrial piping where corrosion resistance and lightweight thermoplastic valves are preferred.
• Typical users: valve manufacturers, piping system designers, plant engineers, procurement/specification writers, and quality/test laboratories evaluating diaphragm valves made of thermoplastics.
• Useful when selecting valves by DN, PN/Class, material compatibility (chemical resistance), and required lifetime / temperature rating.

Related standards

• Normative references cited include ISO 15493, ISO 15494, ISO 10931 (thermoplastic component specifications) and valve testing/terminology standards such as EN 12266-1, ISO 8233, ISO 8659 and flange/connection standards (EN 1092-1, EN 1759-1). These should be consulted for detailed material, testing and connection specifications.

Keywords: ISO 16138, diaphragm valves, thermoplastics, pressure temperature rating, DN PN, PVDF, PVC-U, ABS, industrial valves, valve testing.