Overview
ISO 13844:2022 defines a standardized test method for leaktightness of elastomeric-sealing-ring-type socket joints used with plastic pressure pipes. The standard describes how to evaluate joint performance under negative internal pressure (partial vacuum), angular deflection and pipe deformation. It is intended for assembled joints between elastomeric-sealed sockets (plastic or metal) and plastic pipes and supports consistent type testing, quality control and conformity assessment of plastic piping systems.
Key topics and requirements
- Test principle: A pipe section restrained in a socket is subjected to a specified negative internal pressure while undergoing angular deflection and, where required, diametric deformation; the joint is inspected for leakage over the test period.
- Test parameters: The referring standard or Annex A specifies test medium, pressures, duration, temperature, deformation (%), angle of deflection (°) and free length (L). Annex A gives typical values:
- Test medium: air
- Test temperature: 20 ± 5 °C
- Deformation: 5 %
- Angle of deflection: 2°
- Two negative gauge pressures: −0.1 ± 0.02 bar and −0.8 ± 0.02 bar (≈ −10 kPa and −80 kPa)
- Free length L = 5 × nominal outside diameter (min 500 mm, max 1 500 mm)
- Apparatus: Framework with fixed and movable fixtures to apply angular deflection; vacuum source and vacuum gauge (accuracy ±1%); isolation valve; mechanical/hydraulic device and deforming beams sized per pipe diameter (beam width rules: 100 mm, 150 mm, 200 mm).
- Procedure controls: Maintain temperature within ±2 °C; isolate pump after reaching target vacuum and monitor pressure change (stop if change > 0.05 bar); measure deformation at the beam face adjacent to socket mouth.
- Test report: Must reference ISO 13844:2022, include component IDs, nominal pressure class or series, angle, temperature, duration, deformation, leak information, deviations and test date.
Applications and users
ISO 13844 is used by:
- Manufacturers of plastic pipes and elastomeric-sealed sockets for type testing and design validation
- Independent test laboratories and certification bodies performing leak tightness testing
- Quality assurance teams for production control and batch verification
- Designers, utilities and infrastructure owners specifying reliable socket joint performance in pressure piping systems
Practical applications include verification of joints for potable water, sewage, drainage and other plastic pressure pipeline systems where sealing under negative pressure and flexibility under deflection are critical.
Related standards
- Prepared by ISO/TC 138 (Plastics pipes) in collaboration with CEN/TC 155.
- The beam shape used in ISO 13844:2022 is aligned with ISO 13259 as noted in the foreword.
Keywords: ISO 13844:2022, elastomeric-sealing-ring, socket joints, plastic piping systems, negative pressure test, angular deflection, deformation, leaktightness testing.
Open preview (PDF)Plastics piping systems — Elastomeric-sealing-ring-type socket joints for use with plastic pipes — Test method for leaktightness under negative pressure, angular deflection and deformation
