ISO 13477 specifies a procedure for testing the slow crack growth resistance of polyethylene and other thermoplastic pipes using notched ring specimens under constant internal pressure, providing standardized results to assess long-term durability and support material comparison in the plastic pipe industry.
Introduction to ISO 13477
ISO 13477 is an internationally recognized standard that specifies a test method for determining the resistance to slow crack growth (SCG) of polyethylene (PE) and other thermoplastics in pipe form. The standard outlines the procedures and equipment needed to evaluate how plastic pipes perform when subjected to sustained internal pressure. ISO 13477 plays an important role in assessing the long-term durability and reliability of plastic piping systems, especially those used for transporting water, gas, and other pressurized fluids.
Scope of application
The ISO 13477 standard addresses a key failure mode—slow crack growth—that can affect the service life of buried plastic pipes. The method can be applied to pipes, fittings, or raw materials formed into test specimens. Results generated by ISO 13477 are often used to predict the operational performance of piping systems over extended timeframes, enabling manufacturers and end-users to compare materials and product designs based on their SCG resistance.
Testing parameters and procedures
The SCG resistance test under ISO 13477 is typically conducted using a notched pipe ring under constant internal pressure and at controlled temperatures. Parameters such as notch depth, internal pressure, and temperature are defined to ensure reproducible and consistent test results. Testing continues until the specimen fails or reaches a predetermined endpoint. The standard provides precise definitions for preparation, test setup, and evaluation of results, supporting repeatability across laboratories.
Takeaway
ISO 13477 offers a clear framework for measuring slow crack growth resistance in thermoplastic pipes, supporting consistent product evaluation across the plastic piping industry.
Overview of the procedure
Conducting a slow crack growth resistance test according to ISO 13477 involves specific sample preparation, notching, controlled pressurization, and environmental conditioning. The test process yields data critical for material comparison and quality evaluation in the plastic pipe industry. Following each step accurately ensures that test results remain consistent and meaningful across laboratories and product runs.
Preparing the sample and test setup
Specimens are typically cut from a pipe or fabricated into rings, with notches introduced at precise locations. All dimensional requirements are dictated by the standard. Test equipment is calibrated and configured to apply a defined internal pressure and control temperature around the samples.
Executing the test and monitoring
The test begins when internal pressure is applied to the notched specimens and maintained at a steady level. Throughout the process, temperature and pressure are continuously monitored. The duration to failure or maximum test time is recorded for each sample. All observations are logged, including any deviations or anomalies discovered during the test run.
Collecting and analyzing results
After completion, failure times are analyzed according to ISO 13477 instructions. Results can be used to calculate material performance indices and compare the SCG resistance of various batches or product designs. Proper documentation and archiving of both raw data and calculated outcomes are expected as part of the process.
Key points to remember
By adhering to ISO 13477 testing procedures, laboratories can reliably determine how thermoplastic pipes will perform in challenging conditions involving slow crack growth. Consistency and precision in following the method are crucial for obtaining reproducible and industry-accepted results.
Summary
ISO 13477 provides a systematic means to evaluate the slow crack growth resistance of plastic pipes, supporting both quality control and material development. Careful attention to sample preparation, pressurization, and test monitoring ensures reliable outcomes.
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