Thermoplastics pipes - Longitudinal reversion - Test method and parameters (ISO 2505:2023)

This document specifies a test method and associated parameters for determining the longitudinal shrinkage of thermoplastic pipes and fittings. The procedure is applicable to both newly manufactured products and those that have undergone processing or installation. It outlines the conditions under which samples are subjected to thermal stress, allowing for the measurement of dimensional changes that occur along the longitudinal axis. The method involves placing test pieces in an oven or a fluid bath at a specified temperature for a defined duration. Following the exposure period, the samples are cooled, and the change in length is measured with precision instruments. Results are typically expressed as a percentage of the original length. This approach ensures consistency in evaluating the thermal stability and quality control of thermoplastic piping systems across various applications. The parameter definitions provided assist in interpreting the shrinkage behavior under specific environmental conditions, facilitating comparative analysis in manufacturing and quality assurance processes without requiring subjective assessment of the utility or necessity of the method itself.