ISO 9967 specifies a method for determining the creep ratio of thermoplastics pipes under a constant compressive load. The standard evaluates how a pipe deforms over time when subjected to sustained external pressure, providing information about its long-term mechanical performance.

The test applies a defined compressive force to a pipe specimen and measures the change in diameter over a specified time period. The calculated creep ratio helps to assess the pipe’s resistance to long-term deformation and its suitability for applications such as buried piping systems and pressure-independent installations.

For more information about this test method, please visit the official ISO website.