Overview
EN ISO 19892:2018 (identical to ISO 19892:2011) defines a standardized test method for the resistance of joints to pressure cycling in thermoplastics piping systems intended for hot and cold water. The standard describes how to prepare, condition and cyclically pressurize assemblies of pipes and fittings, monitor for leakage, and report results - providing a repeatable way to assess joint durability under fluctuating pressures.
Key topics and requirements
- Scope: Applies to thermoplastics pipes and fittings for hot and cold water applications; evaluates joint performance under repeated positive pressure cycles.
- Test principle: An assembly is subjected to water pressure cycling between two positive pressure limits at a specified temperature and inspected for leakage.
- Default test parameters (unless the referencing standard specifies otherwise):
- Number of test pieces: 3
- Test/conditioning temperature: (23 ± 2) °C
- Cycle frequency: (30 ± 5) cycles per minute
- Number of cycles: 10 000
- Test pressure limits: depend on design pressure (examples from the standard)
- design pD = 4 bar → upper 6 bar / lower 0.5 bar
- pD = 6 bar → upper 9 bar / lower 0.5 bar
- pD = 8 bar → upper 12 bar / lower 0.5 bar
- pD = 10 bar → upper 15 bar / lower 0.5 bar
- Apparatus and measurement:
- Pressurizing device able to generate sinusoidal or trapezoidal pressure waves
- Pressure measurement accuracy ±5% with waveform recording
- Temperature-controlled test chamber (±2 °C)
- End-sealing device that does not impose longitudinal forces on joints
- Specimen preparation and conditioning:
- Assemblies made per manufacturer’s joining practice
- Minimum free length each side of fitting: greater of 1.5·d or 300 mm (d = outside diameter)
- Conditioning period depends on pipe wall thickness (e):
